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Since gup-fast doesn't have the vma reference, teach it to detect such huge
pfnmaps by checking the special bit for pmd/pud too, just like ptes.
Link: https://lkml.kernel.org/r/20240826204353.2228736-6-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Gavin Shan <gshan@redhat.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Niklas Schnelle <schnelle@linux.ibm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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This enables PFNMAPs to be mapped at either pmd/pud layers. Generalize the
dax case into vma_is_special_huge() so as to cover both. Meanwhile, rename
the macro to THP_ORDERS_ALL_SPECIAL.
Link: https://lkml.kernel.org/r/20240826204353.2228736-5-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Gavin Shan <gshan@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Niklas Schnelle <schnelle@linux.ibm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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We need these special bits to be around on pfnmaps. Mark properly for
!devmap case, reflecting that there's no page struct backing the entry.
Link: https://lkml.kernel.org/r/20240826204353.2228736-4-peterx@redhat.com
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Gavin Shan <gshan@redhat.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Niklas Schnelle <schnelle@linux.ibm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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It constantly returns false since 2017. One assertion is added in 2019 but
it should never have triggered, IOW it means what is checked should be
asserted instead.
If it didn't exist for 7 years maybe it's good idea to remove it and only
add it when it comes.
Link: https://lkml.kernel.org/r/20240826204353.2228736-3-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Gavin Shan <gshan@redhat.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Niklas Schnelle <schnelle@linux.ibm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patch series "mm: Support huge pfnmaps", v2.
Overview
========
This series implements huge pfnmaps support for mm in general. Huge
pfnmap allows e.g. VM_PFNMAP vmas to map in either PMD or PUD levels,
similar to what we do with dax / thp / hugetlb so far to benefit from TLB
hits. Now we extend that idea to PFN mappings, e.g. PCI MMIO bars where
it can grow as large as 8GB or even bigger.
Currently, only x86_64 (1G+2M) and arm64 (2M) are supported. The last
patch (from Alex Williamson) will be the first user of huge pfnmap, so as
to enable vfio-pci driver to fault in huge pfn mappings.
Implementation
==============
In reality, it's relatively simple to add such support comparing to many
other types of mappings, because of PFNMAP's specialties when there's no
vmemmap backing it, so that most of the kernel routines on huge mappings
should simply already fail for them, like GUPs or old-school follow_page()
(which is recently rewritten to be folio_walk* APIs by David).
One trick here is that we're still unmature on PUDs in generic paths here
and there, as DAX is so far the only user. This patchset will add the 2nd
user of it. Hugetlb can be a 3rd user if the hugetlb unification work can
go on smoothly, but to be discussed later.
The other trick is how to allow gup-fast working for such huge mappings
even if there's no direct sign of knowing whether it's a normal page or
MMIO mapping. This series chose to keep the pte_special solution, so that
it reuses similar idea on setting a special bit to pfnmap PMDs/PUDs so
that gup-fast will be able to identify them and fail properly.
Along the way, we'll also notice that the major pgtable pfn walker, aka,
follow_pte(), will need to retire soon due to the fact that it only works
with ptes. A new set of simple API is introduced (follow_pfnmap* API) to
be able to do whatever follow_pte() can already do, plus that it can also
process huge pfnmaps now. Half of this series is about that and
converting all existing pfnmap walkers to use the new API properly.
Hopefully the new API also looks better to avoid exposing e.g. pgtable
lock details into the callers, so that it can be used in an even more
straightforward way.
Here, three more options will be introduced and involved in huge pfnmap:
- ARCH_SUPPORTS_HUGE_PFNMAP
Arch developers will need to select this option when huge pfnmap is
supported in arch's Kconfig. After this patchset applied, both x86_64
and arm64 will start to enable it by default.
- ARCH_SUPPORTS_PMD_PFNMAP / ARCH_SUPPORTS_PUD_PFNMAP
These options are for driver developers to identify whether current
arch / config supports huge pfnmaps, making decision on whether it can
use the huge pfnmap APIs to inject them. One can refer to the last
vfio-pci patch from Alex on the use of them properly in a device
driver.
So after the whole set applied, and if one would enable some dynamic debug
lines in vfio-pci core files, we should observe things like:
vfio-pci 0000:00:06.0: vfio_pci_mmap_huge_fault(,order = 9) BAR 0 page offset 0x0: 0x100
vfio-pci 0000:00:06.0: vfio_pci_mmap_huge_fault(,order = 9) BAR 0 page offset 0x200: 0x100
vfio-pci 0000:00:06.0: vfio_pci_mmap_huge_fault(,order = 9) BAR 0 page offset 0x400: 0x100
In this specific case, it says that vfio-pci faults in PMDs properly for a
few BAR0 offsets.
Patch Layout
============
Patch 1: Introduce the new options mentioned above for huge PFNMAPs
Patch 2: A tiny cleanup
Patch 3-8: Preparation patches for huge pfnmap (include introduce
special bit for pmd/pud)
Patch 9-16: Introduce follow_pfnmap*() API, use it everywhere, and
then drop follow_pte() API
Patch 17: Add huge pfnmap support for x86_64
Patch 18: Add huge pfnmap support for arm64
Patch 19: Add vfio-pci support for all kinds of huge pfnmaps (Alex)
TODO
====
More architectures / More page sizes
------------------------------------
Currently only x86_64 (2M+1G) and arm64 (2M) are supported. There seems
to have plan to support arm64 1G later on top of this series [2].
Any arch will need to first support THP / THP_1G, then provide a special
bit in pmds/puds to support huge pfnmaps.
remap_pfn_range() support
-------------------------
Currently, remap_pfn_range() still only maps PTEs. With the new option,
remap_pfn_range() can logically start to inject either PMDs or PUDs when
the alignment requirements match on the VAs.
When the support is there, it should be able to silently benefit all
drivers that is using remap_pfn_range() in its mmap() handler on better
TLB hit rate and overall faster MMIO accesses similar to processor on
hugepages.
More driver support
-------------------
VFIO is so far the only consumer for the huge pfnmaps after this series
applied. Besides above remap_pfn_range() generic optimization, device
driver can also try to optimize its mmap() on a better VA alignment for
either PMD/PUD sizes. This may, iiuc, normally require userspace changes,
as the driver doesn't normally decide the VA to map a bar. But I don't
think I know all the drivers to know the full picture.
Credits all go to Alex on help testing the GPU/NIC use cases above.
[0] https://lore.kernel.org/r/73ad9540-3fb8-4154-9a4f-30a0a2b03d41@lucifer.local
[1] https://lore.kernel.org/r/20240807194812.819412-1-peterx@redhat.com
[2] https://lore.kernel.org/r/498e0731-81a4-4f75-95b4-a8ad0bcc7665@huawei.com
This patch (of 19):
This patch introduces the option to introduce special pte bit into
pmd/puds. Archs can start to define pmd_special / pud_special when
supported by selecting the new option. Per-arch support will be added
later.
Before that, create fallbacks for these helpers so that they are always
available.
Link: https://lkml.kernel.org/r/20240826204353.2228736-1-peterx@redhat.com
Link: https://lkml.kernel.org/r/20240826204353.2228736-2-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Gavin Shan <gshan@redhat.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Niklas Schnelle <schnelle@linux.ibm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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In commit 96cfe2c0fd23 ("mm/madvise: replace ptrace attach requirement for
process_madvise") process_madvise() was updated to require the caller to
possess the CAP_SYS_NICE capability to perform the operation, in addition
to a check against PTRACE_MODE_READ performed by mm_access().
The mm_access() function explicitly checks to see if the address space of
the process being referenced is the current one, in which case no check is
performed.
We, however, do not do this when checking the CAP_SYS_NICE capability. This
means that we insist on the caller possessing this capability in order to
perform madvise() operations on its own address space, which seems
nonsensical.
Simply add a check to allow for an invocation of this function with pidfd
set to the current process without elevation.
Link: https://lkml.kernel.org/r/20240913140628.77047-1-lorenzo.stoakes@oracle.com
Fixes: 96cfe2c0fd23 ("mm/madvise: replace ptrace attach requirement for process_madvise")
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Ensure huge_zero_folio won't have large_rmappable flag set. So it can be
reported as thp,zero correctly through stable_page_flags().
Link: https://lkml.kernel.org/r/20240914015306.3656791-1-linmiaohe@huawei.com
Fixes: 5691753d73a2 ("mm: convert huge_zero_page to huge_zero_folio")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Syzbot reports a UAF in hugetlb_fault(). This happens because
vmf_anon_prepare() could drop the per-VMA lock and allow the current VMA
to be freed before hugetlb_vma_unlock_read() is called.
We can fix this by using a modified version of vmf_anon_prepare() that
doesn't release the VMA lock on failure, and then release it ourselves
after hugetlb_vma_unlock_read().
Link: https://lkml.kernel.org/r/20240914194243.245-2-vishal.moola@gmail.com
Fixes: 9acad7ba3e25 ("hugetlb: use vmf_anon_prepare() instead of anon_vma_prepare()")
Reported-by: syzbot+2dab93857ee95f2eeb08@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-mm/00000000000067c20b06219fbc26@google.com/
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Some callers of vmf_anon_prepare() may not want us to release the per-VMA
lock ourselves. Rename vmf_anon_prepare() to __vmf_anon_prepare() and let
the callers drop the lock when desired.
Also, make vmf_anon_prepare() a wrapper that releases the per-VMA lock
itself for any callers that don't care.
This is in preparation to fix this bug reported by syzbot:
https://lore.kernel.org/linux-mm/00000000000067c20b06219fbc26@google.com/
Link: https://lkml.kernel.org/r/20240914194243.245-1-vishal.moola@gmail.com
Fixes: 9acad7ba3e25 ("hugetlb: use vmf_anon_prepare() instead of anon_vma_prepare()")
Reported-by: syzbot+2dab93857ee95f2eeb08@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-mm/00000000000067c20b06219fbc26@google.com/
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Each zsmalloc pool maintains several named kmem-caches for zs_handle-s and
zspage-s. On a system with multiple zsmalloc pools and CONFIG_DEBUG_VM
this triggers kmem_cache_sanity_check():
kmem_cache of name 'zspage' already exists
WARNING: at mm/slab_common.c:108 do_kmem_cache_create_usercopy+0xb5/0x310
...
kmem_cache of name 'zs_handle' already exists
WARNING: at mm/slab_common.c:108 do_kmem_cache_create_usercopy+0xb5/0x310
...
We provide zram device name when init its zsmalloc pool, so we can use
that same name for zsmalloc caches and, hence, create unique names that
can easily be linked to zram device that has created them.
So instead of having this
cat /proc/slabinfo
slabinfo - version: 2.1
zspage 46 46 ...
zs_handle 128 128 ...
zspage 34270 34270 ...
zs_handle 34816 34816 ...
zspage 0 0 ...
zs_handle 0 0 ...
We now have this
cat /proc/slabinfo
slabinfo - version: 2.1
zspage-zram2 46 46 ...
zs_handle-zram2 128 128 ...
zspage-zram0 34270 34270 ...
zs_handle-zram0 34816 34816 ...
zspage-zram1 0 0 ...
zs_handle-zram1 0 0 ...
Link: https://lkml.kernel.org/r/20240906035103.2435557-1-senozhatsky@chromium.org
Fixes: 2e40e163a25a ("zsmalloc: decouple handle and object")
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Adds a smoke test to ensure that KASAN in Rust is actually detecting a
Rust-native UAF. There is significant room to expand this test suite,
but this will at least ensure that flags are having the intended effect.
The rename from kasan_test.c to kasan_test_c.c is in order to allow the
single kasan_test.ko test suite to contain both a .o file produced
by the C compiler and one produced by rustc.
Signed-off-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Link: https://lore.kernel.org/r/20240820194910.187826-5-mmaurer@google.com
[ Applied empty line nit, removed double empty line,
applied `rustfmt` and formatted crate comment. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
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Pull io_uring async discard support from Jens Axboe:
"Sitting on top of both the 6.12 block and io_uring core branches,
here's support for async discard through io_uring.
This allows applications to issue async discards, rather than rely on
the blocking sync ioctl discards we already have. The sync support is
difficult to use outside of idle/cleanup periods.
On a real (but slow) device, testing shows the following results when
compared to sync discard:
qd64 sync discard: 21K IOPS, lat avg 3 msec (max 21 msec)
qd64 async discard: 76K IOPS, lat avg 845 usec (max 2.2 msec)
qd64 sync discard: 14K IOPS, lat avg 5 msec (max 25 msec)
qd64 async discard: 56K IOPS, lat avg 1153 usec (max 3.6 msec)
and synthetic null_blk testing with the same queue depth and block
size settings as above shows:
Type Trim size IOPS Lat avg (usec) Lat Max (usec)
==============================================================
sync 4k 144K 444 20314
async 4k 1353K 47 595
sync 1M 56K 1136 21031
async 1M 94K 680 760"
* tag 'for-6.12/io_uring-discard-20240913' of git://git.kernel.dk/linux:
block: implement async io_uring discard cmd
block: introduce blk_validate_byte_range()
filemap: introduce filemap_invalidate_pages
io_uring/cmd: give inline space in request to cmds
io_uring/cmd: expose iowq to cmds
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Pull block updates from Jens Axboe:
- MD changes via Song:
- md-bitmap refactoring (Yu Kuai)
- raid5 performance optimization (Artur Paszkiewicz)
- Other small fixes (Yu Kuai, Chen Ni)
- Add a sysfs entry 'new_level' (Xiao Ni)
- Improve information reported in /proc/mdstat (Mateusz Kusiak)
- NVMe changes via Keith:
- Asynchronous namespace scanning (Stuart)
- TCP TLS updates (Hannes)
- RDMA queue controller validation (Niklas)
- Align field names to the spec (Anuj)
- Metadata support validation (Puranjay)
- A syntax cleanup (Shen)
- Fix a Kconfig linking error (Arnd)
- New queue-depth quirk (Keith)
- Add missing unplug trace event (Keith)
- blk-iocost fixes (Colin, Konstantin)
- t10-pi modular removal and fixes (Alexey)
- Fix for potential BLKSECDISCARD overflow (Alexey)
- bio splitting cleanups and fixes (Christoph)
- Deal with folios rather than rather than pages, speeding up how the
block layer handles bigger IOs (Kundan)
- Use spinlocks rather than bit spinlocks in zram (Sebastian, Mike)
- Reduce zoned device overhead in ublk (Ming)
- Add and use sendpages_ok() for drbd and nvme-tcp (Ofir)
- Fix regression in partition error pointer checking (Riyan)
- Add support for write zeroes and rotational status in nbd (Wouter)
- Add Yu Kuai as new BFQ maintainer. The scheduler has been
unmaintained for quite a while.
- Various sets of fixes for BFQ (Yu Kuai)
- Misc fixes and cleanups (Alvaro, Christophe, Li, Md Haris, Mikhail,
Yang)
* tag 'for-6.12/block-20240913' of git://git.kernel.dk/linux: (120 commits)
nvme-pci: qdepth 1 quirk
block: fix potential invalid pointer dereference in blk_add_partition
blk_iocost: make read-only static array vrate_adj_pct const
block: unpin user pages belonging to a folio at once
mm: release number of pages of a folio
block: introduce folio awareness and add a bigger size from folio
block: Added folio-ized version of bio_add_hw_page()
block, bfq: factor out a helper to split bfqq in bfq_init_rq()
block, bfq: remove local variable 'bfqq_already_existing' in bfq_init_rq()
block, bfq: remove local variable 'split' in bfq_init_rq()
block, bfq: remove bfq_log_bfqg()
block, bfq: merge bfq_release_process_ref() into bfq_put_cooperator()
block, bfq: fix procress reference leakage for bfqq in merge chain
block, bfq: fix uaf for accessing waker_bfqq after splitting
blk-throttle: support prioritized processing of metadata
blk-throttle: remove last_low_overflow_time
drbd: Add NULL check for net_conf to prevent dereference in state validation
nvme-tcp: fix link failure for TCP auth
blk-mq: add missing unplug trace event
mtip32xx: Remove redundant null pointer checks in mtip_hw_debugfs_init()
...
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs file updates from Christian Brauner:
"This is the work to cleanup and shrink struct file significantly.
Right now, (focusing on x86) struct file is 232 bytes. After this
series struct file will be 184 bytes aka 3 cacheline and a spare 8
bytes for future extensions at the end of the struct.
With struct file being as ubiquitous as it is this should make a
difference for file heavy workloads and allow further optimizations in
the future.
- struct fown_struct was embedded into struct file letting it take up
32 bytes in total when really it shouldn't even be embedded in
struct file in the first place. Instead, actual users of struct
fown_struct now allocate the struct on demand. This frees up 24
bytes.
- Move struct file_ra_state into the union containg the cleanup hooks
and move f_iocb_flags out of the union. This closes a 4 byte hole
we created earlier and brings struct file to 192 bytes. Which means
struct file is 3 cachelines and we managed to shrink it by 40
bytes.
- Reorder struct file so that nothing crosses a cacheline.
I suspect that in the future we will end up reordering some members
to mitigate false sharing issues or just because someone does
actually provide really good perf data.
- Shrinking struct file to 192 bytes is only part of the work.
Files use a slab that is SLAB_TYPESAFE_BY_RCU and when a kmem cache
is created with SLAB_TYPESAFE_BY_RCU the free pointer must be
located outside of the object because the cache doesn't know what
part of the memory can safely be overwritten as it may be needed to
prevent object recycling.
That has the consequence that SLAB_TYPESAFE_BY_RCU may end up
adding a new cacheline.
So this also contains work to add a new kmem_cache_create_rcu()
function that allows the caller to specify an offset where the
freelist pointer is supposed to be placed. Thus avoiding the
implicit addition of a fourth cacheline.
- And finally this removes the f_version member in struct file.
The f_version member isn't particularly well-defined. It is mainly
used as a cookie to detect concurrent seeks when iterating
directories. But it is also abused by some subsystems for
completely unrelated things.
It is mostly a directory and filesystem specific thing that doesn't
really need to live in struct file and with its wonky semantics it
really lacks a specific function.
For pipes, f_version is (ab)used to defer poll notifications until
a write has happened. And struct pipe_inode_info is used by
multiple struct files in their ->private_data so there's no chance
of pushing that down into file->private_data without introducing
another pointer indirection.
But pipes don't rely on f_pos_lock so this adds a union into struct
file encompassing f_pos_lock and a pipe specific f_pipe member that
pipes can use. This union of course can be extended to other file
types and is similar to what we do in struct inode already"
* tag 'vfs-6.12.file' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (26 commits)
fs: remove f_version
pipe: use f_pipe
fs: add f_pipe
ubifs: store cookie in private data
ufs: store cookie in private data
udf: store cookie in private data
proc: store cookie in private data
ocfs2: store cookie in private data
input: remove f_version abuse
ext4: store cookie in private data
ext2: store cookie in private data
affs: store cookie in private data
fs: add generic_llseek_cookie()
fs: use must_set_pos()
fs: add must_set_pos()
fs: add vfs_setpos_cookie()
s390: remove unused f_version
ceph: remove unused f_version
adi: remove unused f_version
mm: Removed @freeptr_offset to prevent doc warning
...
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gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs
Pull vfs folio updates from Christian Brauner:
"This contains work to port write_begin and write_end to rely on folios
for various filesystems.
This converts ocfs2, vboxfs, orangefs, jffs2, hostfs, fuse, f2fs,
ecryptfs, ntfs3, nilfs2, reiserfs, minixfs, qnx6, sysv, ufs, and
squashfs.
After this series lands a bunch of the filesystems in this list do not
mention struct page anymore"
* tag 'vfs-6.12.folio' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs: (61 commits)
Squashfs: Ensure all readahead pages have been used
Squashfs: Rewrite and update squashfs_readahead_fragment() to not use page->index
Squashfs: Update squashfs_readpage_block() to not use page->index
Squashfs: Update squashfs_readahead() to not use page->index
Squashfs: Update page_actor to not use page->index
jffs2: Use a folio in jffs2_garbage_collect_dnode()
jffs2: Convert jffs2_do_readpage_nolock to take a folio
buffer: Convert __block_write_begin() to take a folio
ocfs2: Convert ocfs2_write_zero_page to use a folio
fs: Convert aops->write_begin to take a folio
fs: Convert aops->write_end to take a folio
vboxsf: Use a folio in vboxsf_write_end()
orangefs: Convert orangefs_write_begin() to use a folio
orangefs: Convert orangefs_write_end() to use a folio
jffs2: Convert jffs2_write_begin() to use a folio
jffs2: Convert jffs2_write_end() to use a folio
hostfs: Convert hostfs_write_end() to use a folio
fuse: Convert fuse_write_begin() to use a folio
fuse: Convert fuse_write_end() to use a folio
f2fs: Convert f2fs_write_begin() to use a folio
...
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gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs
Pull misc vfs updates from Christian Brauner:
"This contains the usual pile of misc updates:
Features:
- Add F_CREATED_QUERY fcntl() that allows userspace to query whether
a file was actually created. Often userspace wants to know whether
an O_CREATE request did actually create a file without using
O_EXCL. The current logic is that to first attempts to open the
file without O_CREAT | O_EXCL and if ENOENT is returned userspace
tries again with both flags. If that succeeds all is well. If it
now reports EEXIST it retries.
That works fairly well but some corner cases make this more
involved. If this operates on a dangling symlink the first openat()
without O_CREAT | O_EXCL will return ENOENT but the second openat()
with O_CREAT | O_EXCL will fail with EEXIST.
The reason is that openat() without O_CREAT | O_EXCL follows the
symlink while O_CREAT | O_EXCL doesn't for security reasons. So
it's not something we can really change unless we add an explicit
opt-in via O_FOLLOW which seems really ugly.
All available workarounds are really nasty (fanotify, bpf lsm etc)
so add a simple fcntl().
- Try an opportunistic lookup for O_CREAT. Today, when opening a file
we'll typically do a fast lookup, but if O_CREAT is set, the kernel
always takes the exclusive inode lock. This was likely done with
the expectation that O_CREAT means that we always expect to do the
create, but that's often not the case. Many programs set O_CREAT
even in scenarios where the file already exists (see related
F_CREATED_QUERY patch motivation above).
The series contained in the pr rearranges the pathwalk-for-open
code to also attempt a fast_lookup in certain O_CREAT cases. If a
positive dentry is found, the inode_lock can be avoided altogether
and it can stay in rcuwalk mode for the last step_into.
- Expose the 64 bit mount id via name_to_handle_at()
Now that we provide a unique 64-bit mount ID interface in statx(2),
we can now provide a race-free way for name_to_handle_at(2) to
provide a file handle and corresponding mount without needing to
worry about racing with /proc/mountinfo parsing or having to open a
file just to do statx(2).
While this is not necessary if you are using AT_EMPTY_PATH and
don't care about an extra statx(2) call, users that pass full paths
into name_to_handle_at(2) need to know which mount the file handle
comes from (to make sure they don't try to open_by_handle_at a file
handle from a different filesystem) and switching to AT_EMPTY_PATH
would require allocating a file for every name_to_handle_at(2) call
- Add a per dentry expire timeout to autofs
There are two fairly well known automounter map formats, the autofs
format and the amd format (more or less System V and Berkley).
Some time ago Linux autofs added an amd map format parser that
implemented a fair amount of the amd functionality. This was done
within the autofs infrastructure and some functionality wasn't
implemented because it either didn't make sense or required extra
kernel changes. The idea was to restrict changes to be within the
existing autofs functionality as much as possible and leave changes
with a wider scope to be considered later.
One of these changes is implementing the amd options:
1) "unmount", expire this mount according to a timeout (same as
the current autofs default).
2) "nounmount", don't expire this mount (same as setting the
autofs timeout to 0 except only for this specific mount) .
3) "utimeout=<seconds>", expire this mount using the specified
timeout (again same as setting the autofs timeout but only for
this mount)
To implement these options per-dentry expire timeouts need to be
implemented for autofs indirect mounts. This is because all map
keys (mounts) for autofs indirect mounts use an expire timeout
stored in the autofs mount super block info. structure and all
indirect mounts use the same expire timeout.
Fixes:
- Fix missing fput for FSCONFIG_SET_FD in autofs
- Use param->file for FSCONFIG_SET_FD in coda
- Delete the 'fs/netfs' proc subtreee when netfs module exits
- Make sure that struct uid_gid_map fits into a single cacheline
- Don't flush in-flight wb switches for superblocks without cgroup
writeback
- Correcting the idmapping mount example in the idmapping
documentation
- Fix a race between evice_inodes() and find_inode() and iput()
- Refine the show_inode_state() macro definition in writeback code
- Prevent dump_mapping() from accessing invalid dentry.d_name.name
- Show actual source for debugfs in /proc/mounts
- Annotate data-race of busy_poll_usecs in eventpoll
- Don't WARN for racy path_noexec check in exec code
- Handle OOM on mnt_warn_timestamp_expiry()
- Fix some spelling in the iomap design documentation
- Fix typo in procfs comment
- Fix typo in fs/namespace.c comment
Cleanups:
- Add the VFS git tree to the MAINTAINERS file
- Move FMODE_UNSIGNED_OFFSET to fop_flags freeing up another f_mode
bit in struct file bringing us to 5 free f_mode bits
- Remove the __I_DIO_WAKEUP bit from i_state flags as we can simplify
the wait mechanism
- Remove the unused path_put_init() helper
- Replace a __u32 with u32 for s_fsnotify_mask as __u32 is uapi
specific
- Replace the unsigned long i_state member with a u32 i_state member
in struct inode freeing up 4 bytes in struct inode. Instead of
using the bit based wait apis we're now using the var event apis
and using the individual bytes of the i_state member to wait on
state changes
- Explain how per-syscall AT_* flags should be allocated
- Use in_group_or_capable() helper to simplify the posix acl mode
update code
- Switch to LIST_HEAD() in fsync_buffers_list() to simplify the code
- Removed comment about d_rcu_to_refcount() as that function doesn't
exist anymore
- Add kernel documentation for lookup_fast()
- Don't re-zero evenpoll fields
- Remove outdated comment after close_fd()
- Fix imprecise wording in comment about the pipe filesystem
- Drop GFP_NOFAIL mode from alloc_page_buffers
- Missing blank line warnings and struct declaration improved in
file_table
- Annotate struct poll_list with __counted_by()
- Remove the unused read parameter in percpu-rwsem
- Remove linux/prefetch.h include from direct-io code
- Use kmemdup_array instead of kmemdup for multiple allocation in
mnt_idmapping code
- Remove unused mnt_cursor_del() declaration
Performance tweaks:
- Dodge smp_mb in break_lease and break_deleg in the common case
- Only read fops once in fops_{get,put}()
- Use RCU in ilookup()
- Elide smp_mb in iversion handling in the common case
- Drop one lock trip in evict()"
* tag 'vfs-6.12.misc' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs: (58 commits)
uidgid: make sure we fit into one cacheline
proc: Fix typo in the comment
fs/pipe: Correct imprecise wording in comment
fhandle: expose u64 mount id to name_to_handle_at(2)
uapi: explain how per-syscall AT_* flags should be allocated
fs: drop GFP_NOFAIL mode from alloc_page_buffers
writeback: Refine the show_inode_state() macro definition
fs/inode: Prevent dump_mapping() accessing invalid dentry.d_name.name
mnt_idmapping: Use kmemdup_array instead of kmemdup for multiple allocation
netfs: Delete subtree of 'fs/netfs' when netfs module exits
fs: use LIST_HEAD() to simplify code
inode: make i_state a u32
inode: port __I_LRU_ISOLATING to var event
vfs: fix race between evice_inodes() and find_inode()&iput()
inode: port __I_NEW to var event
inode: port __I_SYNC to var event
fs: reorder i_state bits
fs: add i_state helpers
MAINTAINERS: add the VFS git tree
fs: s/__u32/u32/ for s_fsnotify_mask
...
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Merge kmem_cache_create() refactoring by Christian Brauner.
Note this includes a merge of the vfs.file tree that contains the
prerequisity kmem_cache_create_rcu() work.
|
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Merge most of SLUB feature work for 6.12:
- Barrier for pending kfree_rcu() in kmem_cache_destroy() and associated
refactoring of the destroy path (Vlastimil Babka)
- CONFIG_SLUB_RCU_DEBUG to allow KASAN catching UAF bugs in
SLAB_TYPESAFE_BY_RCU caches (Jann Horn)
- kmem_cache_charge() for delayed kmemcg charging (Shakeel Butt)
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As kmem_cache_create() became a _Generic() wrapper macro, it currently
has no kerneldoc despite being the main API to use. Add it. Also adjust
kmem_cache_create_usercopy() kerneldoc to indicate it is now a legacy
wrapper.
Also expand the kerneldoc for struct kmem_cache_args, especially for the
freeptr_offset field, where important details were removed with the
removal of kmem_cache_create_rcu().
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Christian Brauner <brauner@kernel.org>
|
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As Jann points out, PFN mappings are special, because unlike normal
memory mappings, there is no lifetime information associated with the
mapping - it is just a raw mapping of PFNs with no reference counting of
a 'struct page'.
That's all very much intentional, but it does mean that it's easy to
mess up the cleanup in case of errors. Yes, a failed mmap() will always
eventually clean up any partial mappings, but without any explicit
lifetime in the page table mapping itself, it's very easy to do the
error handling in the wrong order.
In particular, it's easy to mistakenly free the physical backing store
before the page tables are actually cleaned up and (temporarily) have
stale dangling PTE entries.
To make this situation less error-prone, just make sure that any partial
pfn mapping is torn down early, before any other error handling.
Reported-and-tested-by: Jann Horn <jannh@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Simona Vetter <simona.vetter@ffwll.ch>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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kiocb_invalidate_pages() is useful for the write path, however not
everything is backed by kiocb and we want to reuse the function for bio
based discard implementation. Extract and and reuse a new helper called
filemap_invalidate_pages(), which takes a argument indicating whether it
should be non-blocking and might return -EAGAIN.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/f81374b52c92d0dce0f01a279d1eed42b54056aa.1726072086.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
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* for-6.12/block: (115 commits)
block: unpin user pages belonging to a folio at once
mm: release number of pages of a folio
block: introduce folio awareness and add a bigger size from folio
block: Added folio-ized version of bio_add_hw_page()
block, bfq: factor out a helper to split bfqq in bfq_init_rq()
block, bfq: remove local variable 'bfqq_already_existing' in bfq_init_rq()
block, bfq: remove local variable 'split' in bfq_init_rq()
block, bfq: remove bfq_log_bfqg()
block, bfq: merge bfq_release_process_ref() into bfq_put_cooperator()
block, bfq: fix procress reference leakage for bfqq in merge chain
block, bfq: fix uaf for accessing waker_bfqq after splitting
blk-throttle: support prioritized processing of metadata
blk-throttle: remove last_low_overflow_time
drbd: Add NULL check for net_conf to prevent dereference in state validation
blk-mq: add missing unplug trace event
mtip32xx: Remove redundant null pointer checks in mtip_hw_debugfs_init()
md: Add new_level sysfs interface
zram: Shrink zram_table_entry::flags.
zram: Remove ZRAM_LOCK
zram: Replace bit spinlocks with a spinlock_t.
...
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Add a new function unpin_user_folio() to put the refs of a folio by
npages count.
The check for BIO_PAGE_PINNED flag is removed as it is already checked
in bio_release_pages().
Signed-off-by: Kundan Kumar <kundan.kumar@samsung.com>
Tested-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/20240911064935.5630-4-kundan.kumar@samsung.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Make __kmem_cache_create() a static inline function.
Signed-off-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
|
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Make kmem_cache_create_usercopy() a static inline function.
Signed-off-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
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Now that we have ported all users of kmem_cache_create_rcu() to struct
kmem_cache_args the function is unused and can be removed.
Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
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Use _Generic() to create a compatibility layer that type switches on the
third argument to either call __kmem_cache_create() or
__kmem_cache_create_args(). If NULL is passed for the struct
kmem_cache_args argument use default args making porting for callers
that don't care about additional arguments easy.
Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
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Pass down struct kmem_cache_args to calculate_sizes() so we can use
args->{use}_freeptr_offset directly. This allows us to remove
->rcu_freeptr_offset from struct kmem_cache.
Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
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and initialize most things in do_kmem_cache_create(). In a follow-up
patch we'll remove rcu_freeptr_offset from struct kmem_cache.
Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
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do_kmem_cache_create() is the only caller and we're going to pass down
struct kmem_cache_args in a follow-up patch.
Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
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Pass struct kmem_cache_args to create_cache() so that we can later
simplify further helpers.
Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
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Port kmem_cache_create_usercopy() to struct kmem_cache_args and remove
the now unused do_kmem_cache_create_usercopy() helper.
Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
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Port kmem_cache_create_rcu() to struct kmem_cache_args.
Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
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Port kmem_cache_create() to struct kmem_cache_args.
Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
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Currently we have multiple kmem_cache_create*() variants that take up to
seven separate parameters with one of the functions having to grow an
eigth parameter in the future to handle both usercopy and a custom
freelist pointer.
Add a struct kmem_cache_args structure and move less common parameters
into it. Core parameters such as name, object size, and flags continue
to be passed separately.
Add a new function __kmem_cache_create_args() that takes a struct
kmem_cache_args pointer and port do_kmem_cache_create_usercopy() over to
it.
In follow-up patches we will port the other kmem_cache_create*()
variants over to it as well.
Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
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Free up reusing the double-underscore variant for follow-up patches.
Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
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At the moment, the slab objects are charged to the memcg at the
allocation time. However there are cases where slab objects are
allocated at the time where the right target memcg to charge it to is
not known. One such case is the network sockets for the incoming
connection which are allocated in the softirq context.
Couple hundred thousand connections are very normal on large loaded
server and almost all of those sockets underlying those connections get
allocated in the softirq context and thus not charged to any memcg.
However later at the accept() time we know the right target memcg to
charge. Let's add new API to charge already allocated objects, so we can
have better accounting of the memory usage.
To measure the performance impact of this change, tcp_crr is used from
the neper [1] performance suite. Basically it is a network ping pong
test with new connection for each ping pong.
The server and the client are run inside 3 level of cgroup hierarchy
using the following commands:
Server:
$ tcp_crr -6
Client:
$ tcp_crr -6 -c -H ${server_ip}
If the client and server run on different machines with 50 GBPS NIC,
there is no visible impact of the change.
For the same machine experiment with v6.11-rc5 as base.
base (throughput) with-patch
tcp_crr 14545 (+- 80) 14463 (+- 56)
It seems like the performance impact is within the noise.
Link: https://github.com/google/neper [1]
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Reviewed-by: Yosry Ahmed <yosryahmed@google.com>
Acked-by: Paolo Abeni <pabeni@redhat.com> # net
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
|
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Add pgalloc_tag_copy() to transfer the codetag from the old folio to the
new one during migration. This makes original allocation sites persist
cross migration rather than lump into the get_new_folio callbacks passed
into migrate_pages(), e.g., compaction_alloc():
# echo 1 >/proc/sys/vm/compact_memory
# grep compaction_alloc /proc/allocinfo
Before this patch:
132968448 32463 mm/compaction.c:1880 func:compaction_alloc
After this patch:
0 0 mm/compaction.c:1880 func:compaction_alloc
Link: https://lkml.kernel.org/r/20240906042108.1150526-3-yuzhao@google.com
Fixes: dcfe378c81f7 ("lib: introduce support for page allocation tagging")
Signed-off-by: Yu Zhao <yuzhao@google.com>
Acked-by: Suren Baghdasaryan <surenb@google.com>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
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The current assumption is that a large folio can only be split into
order-0 folios. That is not the case for hugeTLB demotion, nor for THP
split: see commit c010d47f107f ("mm: thp: split huge page to any lower
order pages").
When a large folio is split into ones of a lower non-zero order, only the
new head pages should be tagged. Tagging tail pages can cause imbalanced
"calls" counters, since only head pages are untagged by pgalloc_tag_sub()
and the "calls" counts on tail pages are leaked, e.g.,
# echo 2048kB >/sys/kernel/mm/hugepages/hugepages-1048576kB/demote_size
# echo 700 >/sys/kernel/mm/hugepages/hugepages-1048576kB/nr_hugepages
# time echo 700 >/sys/kernel/mm/hugepages/hugepages-1048576kB/demote
# echo 0 >/sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages
# grep alloc_gigantic_folio /proc/allocinfo
Before this patch:
0 549427200 mm/hugetlb.c:1549 func:alloc_gigantic_folio
real 0m2.057s
user 0m0.000s
sys 0m2.051s
After this patch:
0 0 mm/hugetlb.c:1549 func:alloc_gigantic_folio
real 0m1.711s
user 0m0.000s
sys 0m1.704s
Not tagging tail pages also improves the splitting time, e.g., by about
15% when demoting 1GB hugeTLB folios to 2MB ones, as shown above.
Link: https://lkml.kernel.org/r/20240906042108.1150526-2-yuzhao@google.com
Fixes: be25d1d4e822 ("mm: create new codetag references during page splitting")
Signed-off-by: Yu Zhao <yuzhao@google.com>
Acked-by: Suren Baghdasaryan <surenb@google.com>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
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In many places, in the comments, we use both "higher-order" and
"high-order" to describe the non 0-order pages. That is confusing,
because a "higher-order" statement does not reflect what it is compared
with.
Link: https://lkml.kernel.org/r/20240906095049.3486-1-urezki@gmail.com
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Suggested-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Baoquan He <bhe@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Use helper function va_size() to improve code readability. No functional
modification involved.
Link: https://lkml.kernel.org/r/20240906102539.3537207-1-zhangpeng362@huawei.com
Signed-off-by: ZhangPeng <zhangpeng362@huawei.com>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
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The tracing of invalidation and truncation operations on large files
showed that xa_get_order() is among the top functions where kernel spends
a lot of CPUs. xa_get_order() needs to traverse the tree to reach the
right node for a given index and then extract the order of the entry.
However it seems like at many places it is being called within an already
happening tree traversal where there is no need to do another traversal.
Just use xas_get_order() at those places.
Link: https://lkml.kernel.org/r/20240906230512.124643-1-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
A clean up to make variable names more clear and to improve code
readability.
No functional change.
Link: https://lkml.kernel.org/r/20240905003058.1859929-6-kinseyho@google.com
Signed-off-by: Kinsey Ho <kinseyho@google.com>
Reviewed-by: T.J. Mercier <tjmercier@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Tejun Heo <tj@kernel.org>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: Zefan Li <lizefan.x@bytedance.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
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Currently, if multiple reclaimers raced on the same position, the
reclaimers which detect the race will still reclaim from the same memcg.
Instead, the reclaimers which detect the race should move on to the next
memcg in the hierarchy.
So, in the case where multiple traversals race, jump back to the start of
the mem_cgroup_iter() function to find the next memcg in the hierarchy to
reclaim from.
Link: https://lkml.kernel.org/r/20240905003058.1859929-5-kinseyho@google.com
Reported-by: syzbot+e099d407346c45275ce9@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/000000000000817cf10620e20d33@google.com/
Signed-off-by: Kinsey Ho <kinseyho@google.com>
Reviewed-by: T.J. Mercier <tjmercier@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Tejun Heo <tj@kernel.org>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: Zefan Li <lizefan.x@bytedance.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
The generation number in struct mem_cgroup_reclaim_iter should be
incremented on every round-trip. Currently, it is possible for a
concurrent reclaimer to jump in at the end of the hierarchy, causing a
traversal restart (resetting the iteration position) without incrementing
the generation number.
By resetting the position without incrementing the generation, it's
possible for another ongoing mem_cgroup_iter() thread to walk the tree
twice.
Move the traversal restart such that the generation number is
incremented before the restart.
Link: https://lkml.kernel.org/r/20240905003058.1859929-4-kinseyho@google.com
Signed-off-by: Kinsey Ho <kinseyho@google.com>
Reviewed-by: T.J. Mercier <tjmercier@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Tejun Heo <tj@kernel.org>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: Zefan Li <lizefan.x@bytedance.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
To obtain the pointer to the next memcg position, mem_cgroup_iter()
currently holds css->refcnt during memcg traversal only to put css->refcnt
at the end of the routine. This isn't necessary as an rcu_read_lock is
already held throughout the function. The use of the RCU read lock with
css_next_descendant_pre() guarantees that sibling linkage is safe without
holding a ref on the passed-in @css.
Remove css->refcnt usage during traversal by leveraging RCU.
Link: https://lkml.kernel.org/r/20240905003058.1859929-3-kinseyho@google.com
Signed-off-by: Kinsey Ho <kinseyho@google.com>
Reviewed-by: T.J. Mercier <tjmercier@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Tejun Heo <tj@kernel.org>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: Zefan Li <lizefan.x@bytedance.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
When has_unaccepted_memory() is unused, it prevents kernel builds
with clang, `make W=1` and CONFIG_WERROR=y:
mm/page_alloc.c:7036:20: error: unused function 'has_unaccepted_memory' [-Werror,-Wunused-function]
7036 | static inline bool has_unaccepted_memory(void)
| ^~~~~~~~~~~~~~~~~~~~~
Fix it by removeing the CONFIG_UNACCEPTED_MEMORY=n stub.
Link: https://lkml.kernel.org/r/20240905142220.49d93337a0abce5690e515d9@linux-foundation.org
Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Closes: https://lkml.kernel.org/r/20240905171553.275054-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
random.h is not needed since commit 6c542ab75714 ("mm/demotion: build
demotion targets based on explicit memory tiers"), all functions moved
into memory-tiers.
nsproxy.h is not needed since commit 228ebcbe634a ("Uninline
find_task_by_xxx set of functions"), no nsproxy, we only call
find_task_by_vpid() now.
hugetlb_cgroup.h is not needed since commit ab5ac90aecf5 ("mm, hugetlb: do
not rely on overcommit limit during migration"), move_hugetlb_state() is
called and it belongs to hugetlb.h, which is already included.
balloon_compaction.h, we have more general movable_operations for non-lru
movable page migration, so it could be dropped.
memremap.h, userfaultfd_k.h and oom.h are introduced for zone device page
migration, but all functions are moved into migrate_device.c, so no needed
anymore too.
Link: https://lkml.kernel.org/r/20240905152432.626877-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
The helper find_get_task_by_vpid() can totally replace the task_struct
find logic in split_huge_pages_pid(), so use it to simplify the code.
Also delete the needless comments for the helper function name already
explains what it's doing here.
Link: https://lkml.kernel.org/r/20240905153028.1205128-1-sunnanyong@huawei.com
Signed-off-by: Nanyong Sun <sunnanyong@huawei.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Use find_get_task_by_vpid() to replace the task_struct find logic in
find_mm_struct(), note that this patch move the ptrace_may_access() call
out from rcu_read_lock() scope, this is ok because it actually does not
need it, find_get_task_by_vpid() already get the pid and task safely,
ptrace_may_access() can use the task safely, like what
sched_core_share_pid() similarly do.
Link: https://lkml.kernel.org/r/20240905153118.1205173-1-sunnanyong@huawei.com
Signed-off-by: Nanyong Sun <sunnanyong@huawei.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
