kernel/linux.git/include/linux/highmem.h, branch linux-5.11.y

Merge branch 'akpm' (patches from Andrew)

2020-12-15T20:53:37+00:00

Merge misc updates from Andrew Morton: - a few random little subsystems - almost all of the MM patches which are staged ahead of linux-next material. I'll trickle to post-linux-next work in as the dependents get merged up. Subsystems affected by this patch series: kthread, kbuild, ide, ntfs, ocfs2, arch, and mm (slab-generic, slab, slub, dax, debug, pagecache, gup, swap, shmem, memcg, pagemap, mremap, hmm, vmalloc, documentation, kasan, pagealloc, memory-failure, hugetlb, vmscan, z3fold, compaction, oom-kill, migration, cma, page-poison, userfaultfd, zswap, zsmalloc, uaccess, zram, and cleanups). * emailed patches from Andrew Morton : (200 commits) mm: cleanup kstrto*() usage mm: fix fall-through warnings for Clang mm: slub: convert sysfs sprintf family to sysfs_emit/sysfs_emit_at mm: shmem: convert shmem_enabled_show to use sysfs_emit_at mm:backing-dev: use sysfs_emit in macro defining functions mm: huge_memory: convert remaining use of sprintf to sysfs_emit and neatening mm: use sysfs_emit for struct kobject * uses mm: fix kernel-doc markups zram: break the strict dependency from lzo zram: add stat to gather incompressible pages since zram set up zram: support page writeback mm/process_vm_access: remove redundant initialization of iov_r mm/zsmalloc.c: rework the list_add code in insert_zspage() mm/zswap: move to use crypto_acomp API for hardware acceleration mm/zswap: fix passing zero to 'PTR_ERR' warning mm/zswap: make struct kernel_param_ops definitions const userfaultfd/selftests: hint the test runner on required privilege userfaultfd/selftests: fix retval check for userfaultfd_open() userfaultfd/selftests: always dump something in modes userfaultfd: selftests: make __{s,u}64 format specifiers portable ...

mm: support THPs in zero_user_segments

2020-12-15T20:13:45+00:00

We can only kmap() one subpage of a THP at a time, so loop over all relevant subpages, skipping ones which don't need to be zeroed. This is too large to inline when THPs are enabled and we actually need highmem, so put it in highmem.c. [willy@infradead.org: start1 was allowed to be less than start2] Link: https://lkml.kernel.org/r/20201124041507.28996-1-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Cc: Yang Shi Cc: Jan Kara Cc: Michal Hocko Cc: Zi Yan Cc: Song Liu Cc: Mel Gorman Cc: Naresh Kamboju Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/highmem: Provide kmap_local*

2020-11-24T13:42:09+00:00

Now that the kmap atomic index is stored in task struct provide a preemptible variant. On context switch the maps of an outgoing task are removed and the map of the incoming task are restored. That's obviously slow, but highmem is slow anyway. The kmap_local.*() functions can be invoked from both preemptible and atomic context. kmap local sections disable migration to keep the resulting virtual mapping address correct, but disable neither pagefaults nor preemption. A wholesale conversion of kmap_atomic to be fully preemptible is not possible because some of the usage sites might rely on the preemption disable for serialization or on the implicit pagefault disable. Needs to be done on a case by case basis. Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20201118204007.468533059@linutronix.de

highmem: High implementation details and document API

2020-11-06T22:14:59+00:00

Move the gory details of kmap & al into a private header and only document the interfaces which are usable by drivers. Signed-off-by: Thomas Gleixner Cc: Linus Torvalds Cc: Christoph Hellwig Cc: Andrew Morton Link: https://lore.kernel.org/r/20201103095858.827582066@linutronix.de

mm/highmem: Remove the old kmap_atomic cruft

2020-11-06T22:14:58+00:00

All users gone. Signed-off-by: Thomas Gleixner Cc: Linus Torvalds Cc: Christoph Hellwig Cc: Andrew Morton Cc: Arnd Bergmann Link: https://lore.kernel.org/r/20201103095858.516281567@linutronix.de

highmem: Get rid of kmap_types.h

2020-11-06T22:14:58+00:00

The header is not longer used and on alpha, ia64, openrisc, parisc and um it was completely unused anyway as these architectures have no highmem support. Signed-off-by: Thomas Gleixner Cc: Christoph Hellwig Cc: Andrew Morton Cc: Arnd Bergmann Link: https://lore.kernel.org/r/20201103095858.422094352@linutronix.de

x86/mm/highmem: Use generic kmap atomic implementation

2020-11-06T22:14:55+00:00

Convert X86 to the generic kmap atomic implementation and make the iomap_atomic() naming convention consistent while at it. Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20201103095857.375127260@linutronix.de

highmem: Provide generic variant of kmap_atomic*

2020-11-06T22:14:54+00:00

The kmap_atomic* interfaces in all architectures are pretty much the same except for post map operations (flush) and pre- and post unmap operations. Provide a generic variant for that. Signed-off-by: Thomas Gleixner Cc: Linus Torvalds Cc: Christoph Hellwig Cc: Andrew Morton Link: https://lore.kernel.org/r/20201103095857.175939340@linutronix.de

highmem: Remove unused functions

2020-11-06T22:14:53+00:00

Nothing uses totalhigh_pages_dec() and totalhigh_pages_set(). Signed-off-by: Thomas Gleixner Cc: Christoph Hellwig Cc: Andrew Morton Link: https://lore.kernel.org/r/20201103095856.732891880@linutronix.de

include/linux/highmem.h: fix duplicated words in a comment

2020-08-12T17:57:57+00:00

Change the doubled word "is" in a comment to "it is". Signed-off-by: Randy Dunlap Signed-off-by: Andrew Morton Reviewed-by: Andrew Morton Link: http://lkml.kernel.org/r/ad605959-0083-4794-8d31-6b073300dd6f@infradead.org Signed-off-by: Linus Torvalds