kernel/linux.git/arch/alpha/mm, branch linux-5.9.y

mm/alpha: use general page fault accounting

2020-08-12T17:58:03+00:00

Use the general page fault accounting by passing regs into handle_mm_fault(). Add the missing PERF_COUNT_SW_PAGE_FAULTS perf events too. Note, the other two perf events (PERF_COUNT_SW_PAGE_FAULTS_[MAJ|MIN]) were done in handle_mm_fault(). Signed-off-by: Peter Xu Signed-off-by: Andrew Morton Cc: Richard Henderson Cc: Ivan Kokshaysky Cc: Matt Turner Link: http://lkml.kernel.org/r/20200707225021.200906-3-peterx@redhat.com Signed-off-by: Linus Torvalds

mm: do page fault accounting in handle_mm_fault

2020-08-12T17:58:02+00:00

Patch series "mm: Page fault accounting cleanups", v5. This is v5 of the pf accounting cleanup series. It originates from Gerald Schaefer's report on an issue a week ago regarding to incorrect page fault accountings for retried page fault after commit 4064b9827063 ("mm: allow VM_FAULT_RETRY for multiple times"): https://lore.kernel.org/lkml/20200610174811.44b94525@thinkpad/ What this series did: - Correct page fault accounting: we do accounting for a page fault (no matter whether it's from #PF handling, or gup, or anything else) only with the one that completed the fault. For example, page fault retries should not be counted in page fault counters. Same to the perf events. - Unify definition of PERF_COUNT_SW_PAGE_FAULTS: currently this perf event is used in an adhoc way across different archs. Case (1): for many archs it's done at the entry of a page fault handler, so that it will also cover e.g. errornous faults. Case (2): for some other archs, it is only accounted when the page fault is resolved successfully. Case (3): there're still quite some archs that have not enabled this perf event. Since this series will touch merely all the archs, we unify this perf event to always follow case (1), which is the one that makes most sense. And since we moved the accounting into handle_mm_fault, the other two MAJ/MIN perf events are well taken care of naturally. - Unify definition of "major faults": the definition of "major fault" is slightly changed when used in accounting (not VM_FAULT_MAJOR). More information in patch 1. - Always account the page fault onto the one that triggered the page fault. This does not matter much for #PF handlings, but mostly for gup. More information on this in patch 25. Patchset layout: Patch 1: Introduced the accounting in handle_mm_fault(), not enabled. Patch 2-23: Enable the new accounting for arch #PF handlers one by one. Patch 24: Enable the new accounting for the rest outliers (gup, iommu, etc.) Patch 25: Cleanup GUP task_struct pointer since it's not needed any more This patch (of 25): This is a preparation patch to move page fault accountings into the general code in handle_mm_fault(). This includes both the per task flt_maj/flt_min counters, and the major/minor page fault perf events. To do this, the pt_regs pointer is passed into handle_mm_fault(). PERF_COUNT_SW_PAGE_FAULTS should still be kept in per-arch page fault handlers. So far, all the pt_regs pointer that passed into handle_mm_fault() is NULL, which means this patch should have no intented functional change. Suggested-by: Linus Torvalds Signed-off-by: Peter Xu Signed-off-by: Andrew Morton Cc: Albert Ou Cc: Alexander Gordeev Cc: Andy Lutomirski Cc: Benjamin Herrenschmidt Cc: Borislav Petkov Cc: Brian Cain Cc: Catalin Marinas Cc: Christian Borntraeger Cc: Chris Zankel Cc: Dave Hansen Cc: David S. Miller Cc: Geert Uytterhoeven Cc: Gerald Schaefer Cc: Greentime Hu Cc: Guo Ren Cc: Heiko Carstens Cc: Helge Deller Cc: H. Peter Anvin Cc: Ingo Molnar Cc: Ivan Kokshaysky Cc: James E.J. Bottomley Cc: John Hubbard Cc: Jonas Bonn Cc: Ley Foon Tan Cc: "Luck, Tony" Cc: Matt Turner Cc: Max Filippov Cc: Michael Ellerman Cc: Michal Simek Cc: Nick Hu Cc: Palmer Dabbelt Cc: Paul Mackerras Cc: Paul Walmsley Cc: Pekka Enberg Cc: Peter Zijlstra Cc: Richard Henderson Cc: Rich Felker Cc: Russell King Cc: Stafford Horne Cc: Stefan Kristiansson Cc: Thomas Bogendoerfer Cc: Thomas Gleixner Cc: Vasily Gorbik Cc: Vincent Chen Cc: Vineet Gupta Cc: Will Deacon Cc: Yoshinori Sato Link: http://lkml.kernel.org/r/20200707225021.200906-1-peterx@redhat.com Link: http://lkml.kernel.org/r/20200707225021.200906-2-peterx@redhat.com Signed-off-by: Linus Torvalds

mm: remove unneeded includes of

2020-08-07T18:33:26+00:00

Patch series "mm: cleanup usage of " Most architectures have very similar versions of pXd_alloc_one() and pXd_free_one() for intermediate levels of page table. These patches add generic versions of these functions in and enable use of the generic functions where appropriate. In addition, functions declared and defined in headers are used mostly by core mm and early mm initialization in arch and there is no actual reason to have the included all over the place. The first patch in this series removes unneeded includes of In the end it didn't work out as neatly as I hoped and moving pXd_alloc_track() definitions to would require unnecessary changes to arches that have custom page table allocations, so I've decided to move lib/ioremap.c to mm/ and make pgalloc-track.h local to mm/. This patch (of 8): In most cases header is required only for allocations of page table memory. Most of the .c files that include that header do not use symbols declared in and do not require that header. As for the other header files that used to include , it is possible to move that include into the .c file that actually uses symbols from and drop the include from the header file. The process was somewhat automated using sed -i -E '/[<"]asm\/pgalloc\.h/d' \ $(grep -L -w -f /tmp/xx \ $(git grep -E -l '[<"]asm/pgalloc\.h')) where /tmp/xx contains all the symbols defined in arch/*/include/asm/pgalloc.h. [rppt@linux.ibm.com: fix powerpc warning] Signed-off-by: Mike Rapoport Signed-off-by: Andrew Morton Reviewed-by: Pekka Enberg Acked-by: Geert Uytterhoeven [m68k] Cc: Abdul Haleem Cc: Andy Lutomirski Cc: Arnd Bergmann Cc: Christophe Leroy Cc: Joerg Roedel Cc: Max Filippov Cc: Peter Zijlstra Cc: Satheesh Rajendran Cc: Stafford Horne Cc: Stephen Rothwell Cc: Steven Rostedt Cc: Joerg Roedel Cc: Matthew Wilcox Link: http://lkml.kernel.org/r/20200627143453.31835-1-rppt@kernel.org Link: http://lkml.kernel.org/r/20200627143453.31835-2-rppt@kernel.org Signed-off-by: Linus Torvalds

mmap locking API: convert mmap_sem API comments

2020-06-09T16:39:14+00:00

Convert comments that reference old mmap_sem APIs to reference corresponding new mmap locking APIs instead. Signed-off-by: Michel Lespinasse Signed-off-by: Andrew Morton Reviewed-by: Vlastimil Babka Reviewed-by: Davidlohr Bueso Reviewed-by: Daniel Jordan Cc: David Rientjes Cc: Hugh Dickins Cc: Jason Gunthorpe Cc: Jerome Glisse Cc: John Hubbard Cc: Laurent Dufour Cc: Liam Howlett Cc: Matthew Wilcox Cc: Peter Zijlstra Cc: Ying Han Link: http://lkml.kernel.org/r/20200520052908.204642-12-walken@google.com Signed-off-by: Linus Torvalds

mmap locking API: use coccinelle to convert mmap_sem rwsem call sites

2020-06-09T16:39:14+00:00

This change converts the existing mmap_sem rwsem calls to use the new mmap locking API instead. The change is generated using coccinelle with the following rule: // spatch --sp-file mmap_lock_api.cocci --in-place --include-headers --dir . @@ expression mm; @@ ( -init_rwsem +mmap_init_lock | -down_write +mmap_write_lock | -down_write_killable +mmap_write_lock_killable | -down_write_trylock +mmap_write_trylock | -up_write +mmap_write_unlock | -downgrade_write +mmap_write_downgrade | -down_read +mmap_read_lock | -down_read_killable +mmap_read_lock_killable | -down_read_trylock +mmap_read_trylock | -up_read +mmap_read_unlock ) -(&mm->mmap_sem) +(mm) Signed-off-by: Michel Lespinasse Signed-off-by: Andrew Morton Reviewed-by: Daniel Jordan Reviewed-by: Laurent Dufour Reviewed-by: Vlastimil Babka Cc: Davidlohr Bueso Cc: David Rientjes Cc: Hugh Dickins Cc: Jason Gunthorpe Cc: Jerome Glisse Cc: John Hubbard Cc: Liam Howlett Cc: Matthew Wilcox Cc: Peter Zijlstra Cc: Ying Han Link: http://lkml.kernel.org/r/20200520052908.204642-5-walken@google.com Signed-off-by: Linus Torvalds

mm: don't include asm/pgtable.h if linux/mm.h is already included

2020-06-09T16:39:13+00:00

Patch series "mm: consolidate definitions of page table accessors", v2. The low level page table accessors (pXY_index(), pXY_offset()) are duplicated across all architectures and sometimes more than once. For instance, we have 31 definition of pgd_offset() for 25 supported architectures. Most of these definitions are actually identical and typically it boils down to, e.g. static inline unsigned long pmd_index(unsigned long address) { return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1); } static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address) { return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(address); } These definitions can be shared among 90% of the arches provided XYZ_SHIFT, PTRS_PER_XYZ and xyz_page_vaddr() are defined. For architectures that really need a custom version there is always possibility to override the generic version with the usual ifdefs magic. These patches introduce include/linux/pgtable.h that replaces include/asm-generic/pgtable.h and add the definitions of the page table accessors to the new header. This patch (of 12): The linux/mm.h header includes to allow inlining of the functions involving page table manipulations, e.g. pte_alloc() and pmd_alloc(). So, there is no point to explicitly include in the files that include . The include statements in such cases are remove with a simple loop: for f in $(git grep -l "include ") ; do sed -i -e '/include / d' $f done Signed-off-by: Mike Rapoport Signed-off-by: Andrew Morton Cc: Arnd Bergmann Cc: Borislav Petkov Cc: Brian Cain Cc: Catalin Marinas Cc: Chris Zankel Cc: "David S. Miller" Cc: Geert Uytterhoeven Cc: Greentime Hu Cc: Greg Ungerer Cc: Guan Xuetao Cc: Guo Ren Cc: Heiko Carstens Cc: Helge Deller Cc: Ingo Molnar Cc: Ley Foon Tan Cc: Mark Salter Cc: Matthew Wilcox Cc: Matt Turner Cc: Max Filippov Cc: Michael Ellerman Cc: Michal Simek Cc: Mike Rapoport Cc: Nick Hu Cc: Paul Walmsley Cc: Richard Weinberger Cc: Rich Felker Cc: Russell King Cc: Stafford Horne Cc: Thomas Bogendoerfer Cc: Thomas Gleixner Cc: Tony Luck Cc: Vincent Chen Cc: Vineet Gupta Cc: Will Deacon Cc: Yoshinori Sato Link: http://lkml.kernel.org/r/20200514170327.31389-1-rppt@kernel.org Link: http://lkml.kernel.org/r/20200514170327.31389-2-rppt@kernel.org Signed-off-by: Linus Torvalds

alpha: simplify detection of memory zone boundaries

2020-06-04T03:09:43+00:00

free_area_init() only requires the definition of maximal PFN for each of the supported zone rater than calculation of actual zone sizes and the sizes of the holes between the zones. After removal of CONFIG_HAVE_MEMBLOCK_NODE_MAP the free_area_init() is available to all architectures. Using this function instead of free_area_init_node() simplifies the zone detection. Signed-off-by: Mike Rapoport Signed-off-by: Andrew Morton Tested-by: Hoan Tran [arm64] Cc: Baoquan He Cc: Brian Cain Cc: Catalin Marinas Cc: "David S. Miller" Cc: Geert Uytterhoeven Cc: Greentime Hu Cc: Greg Ungerer Cc: Guan Xuetao Cc: Guo Ren Cc: Heiko Carstens Cc: Helge Deller Cc: "James E.J. Bottomley" Cc: Jonathan Corbet Cc: Ley Foon Tan Cc: Mark Salter Cc: Matt Turner Cc: Max Filippov Cc: Michael Ellerman Cc: Michal Hocko Cc: Michal Simek Cc: Nick Hu Cc: Paul Walmsley Cc: Richard Weinberger Cc: Rich Felker Cc: Russell King Cc: Stafford Horne Cc: Thomas Bogendoerfer Cc: Tony Luck Cc: Vineet Gupta Cc: Yoshinori Sato Link: http://lkml.kernel.org/r/20200412194859.12663-7-rppt@kernel.org Signed-off-by: Linus Torvalds

mm: free_area_init: use maximal zone PFNs rather than zone sizes

2020-06-04T03:09:43+00:00

Currently, architectures that use free_area_init() to initialize memory map and node and zone structures need to calculate zone and hole sizes. We can use free_area_init_nodes() instead and let it detect the zone boundaries while the architectures will only have to supply the possible limits for the zones. Signed-off-by: Mike Rapoport Signed-off-by: Andrew Morton Tested-by: Hoan Tran [arm64] Reviewed-by: Baoquan He Cc: Brian Cain Cc: Catalin Marinas Cc: "David S. Miller" Cc: Geert Uytterhoeven Cc: Greentime Hu Cc: Greg Ungerer Cc: Guan Xuetao Cc: Guo Ren Cc: Heiko Carstens Cc: Helge Deller Cc: "James E.J. Bottomley" Cc: Jonathan Corbet Cc: Ley Foon Tan Cc: Mark Salter Cc: Matt Turner Cc: Max Filippov Cc: Michael Ellerman Cc: Michal Hocko Cc: Michal Simek Cc: Nick Hu Cc: Paul Walmsley Cc: Richard Weinberger Cc: Rich Felker Cc: Russell King Cc: Stafford Horne Cc: Thomas Bogendoerfer Cc: Tony Luck Cc: Vineet Gupta Cc: Yoshinori Sato Link: http://lkml.kernel.org/r/20200412194859.12663-5-rppt@kernel.org Signed-off-by: Linus Torvalds

mm: remove CONFIG_HAVE_MEMBLOCK_NODE_MAP option

2020-06-04T03:09:43+00:00

CONFIG_HAVE_MEMBLOCK_NODE_MAP is used to differentiate initialization of nodes and zones structures between the systems that have region to node mapping in memblock and those that don't. Currently all the NUMA architectures enable this option and for the non-NUMA systems we can presume that all the memory belongs to node 0 and therefore the compile time configuration option is not required. The remaining few architectures that use DISCONTIGMEM without NUMA are easily updated to use memblock_add_node() instead of memblock_add() and thus have proper correspondence of memblock regions to NUMA nodes. Still, free_area_init_node() must have a backward compatible version because its semantics with and without CONFIG_HAVE_MEMBLOCK_NODE_MAP is different. Once all the architectures will use the new semantics, the entire compatibility layer can be dropped. To avoid addition of extra run time memory to store node id for architectures that keep memblock but have only a single node, the node id field of the memblock_region is guarded by CONFIG_NEED_MULTIPLE_NODES and the corresponding accessors presume that in those cases it is always 0. Signed-off-by: Mike Rapoport Signed-off-by: Andrew Morton Tested-by: Hoan Tran [arm64] Acked-by: Catalin Marinas [arm64] Cc: Baoquan He Cc: Brian Cain Cc: "David S. Miller" Cc: Geert Uytterhoeven Cc: Greentime Hu Cc: Greg Ungerer Cc: Guan Xuetao Cc: Guo Ren Cc: Heiko Carstens Cc: Helge Deller Cc: "James E.J. Bottomley" Cc: Jonathan Corbet Cc: Ley Foon Tan Cc: Mark Salter Cc: Matt Turner Cc: Max Filippov Cc: Michael Ellerman Cc: Michal Hocko Cc: Michal Simek Cc: Nick Hu Cc: Paul Walmsley Cc: Richard Weinberger Cc: Rich Felker Cc: Russell King Cc: Stafford Horne Cc: Thomas Bogendoerfer Cc: Tony Luck Cc: Vineet Gupta Cc: Yoshinori Sato Link: http://lkml.kernel.org/r/20200412194859.12663-4-rppt@kernel.org Signed-off-by: Linus Torvalds

mm: allow VM_FAULT_RETRY for multiple times

2020-04-02T16:35:30+00:00

The idea comes from a discussion between Linus and Andrea [1]. Before this patch we only allow a page fault to retry once. We achieved this by clearing the FAULT_FLAG_ALLOW_RETRY flag when doing handle_mm_fault() the second time. This was majorly used to avoid unexpected starvation of the system by looping over forever to handle the page fault on a single page. However that should hardly happen, and after all for each code path to return a VM_FAULT_RETRY we'll first wait for a condition (during which time we should possibly yield the cpu) to happen before VM_FAULT_RETRY is really returned. This patch removes the restriction by keeping the FAULT_FLAG_ALLOW_RETRY flag when we receive VM_FAULT_RETRY. It means that the page fault handler now can retry the page fault for multiple times if necessary without the need to generate another page fault event. Meanwhile we still keep the FAULT_FLAG_TRIED flag so page fault handler can still identify whether a page fault is the first attempt or not. Then we'll have these combinations of fault flags (only considering ALLOW_RETRY flag and TRIED flag): - ALLOW_RETRY and !TRIED: this means the page fault allows to retry, and this is the first try - ALLOW_RETRY and TRIED: this means the page fault allows to retry, and this is not the first try - !ALLOW_RETRY and !TRIED: this means the page fault does not allow to retry at all - !ALLOW_RETRY and TRIED: this is forbidden and should never be used In existing code we have multiple places that has taken special care of the first condition above by checking against (fault_flags & FAULT_FLAG_ALLOW_RETRY). This patch introduces a simple helper to detect the first retry of a page fault by checking against both (fault_flags & FAULT_FLAG_ALLOW_RETRY) and !(fault_flag & FAULT_FLAG_TRIED) because now even the 2nd try will have the ALLOW_RETRY set, then use that helper in all existing special paths. One example is in __lock_page_or_retry(), now we'll drop the mmap_sem only in the first attempt of page fault and we'll keep it in follow up retries, so old locking behavior will be retained. This will be a nice enhancement for current code [2] at the same time a supporting material for the future userfaultfd-writeprotect work, since in that work there will always be an explicit userfault writeprotect retry for protected pages, and if that cannot resolve the page fault (e.g., when userfaultfd-writeprotect is used in conjunction with swapped pages) then we'll possibly need a 3rd retry of the page fault. It might also benefit other potential users who will have similar requirement like userfault write-protection. GUP code is not touched yet and will be covered in follow up patch. Please read the thread below for more information. [1] https://lore.kernel.org/lkml/20171102193644.GB22686@redhat.com/ [2] https://lore.kernel.org/lkml/20181230154648.GB9832@redhat.com/ Suggested-by: Linus Torvalds Suggested-by: Andrea Arcangeli Signed-off-by: Peter Xu Signed-off-by: Andrew Morton Tested-by: Brian Geffon Cc: Bobby Powers Cc: David Hildenbrand Cc: Denis Plotnikov Cc: "Dr . David Alan Gilbert" Cc: Hugh Dickins Cc: Jerome Glisse Cc: Johannes Weiner Cc: "Kirill A . Shutemov" Cc: Martin Cracauer Cc: Marty McFadden Cc: Matthew Wilcox Cc: Maya Gokhale Cc: Mel Gorman Cc: Mike Kravetz Cc: Mike Rapoport Cc: Pavel Emelyanov Link: http://lkml.kernel.org/r/20200220160246.9790-1-peterx@redhat.com Signed-off-by: Linus Torvalds