- 23 Jul, 2019 8 commits
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Arnaldo Carvalho de Melo authored
So that, when perf_add_probe_events() fails, like in: # perf probe icmp_rcv:64 "type=icmph->type" Failed to find 'icmph' in this function. Error: Failed to add events. Segmentation fault (core dumped) # We don't segfault. clear_perf_probe_event() was zeroing the whole pev, and since the switch to zfree() for the members in the pev, that memset() was removed, which left nargs with its original value, in the above case 1. With the memset the same pev could be passed to clear_perf_probe_event() multiple times, since all it would have would be zeroes, and free() accepts zero, the loop would not happen and we would just memset it again to zeroes. Without it we got that segfault, so zero nargs to keep it like it was, next cset will avoid calling clear_perf_probe_event() for the same pevs in case of failure. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Fixes: d8f9da24 ("perf tools: Use zfree() where applicable") Link: https://lkml.kernel.org/n/tip-802f2jypnwqsvyavvivs8464@git.kernel.orgSigned-off-by:Arnaldo Carvalho de Melo <acme@redhat.com>
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Alexey Budankov authored
Fix decompression failure found during the loading of compressed trace collected on larger scale systems (>48 cores). The error happened due to lack of decompression space for a mmaped buffer data chunk split across adjacent PERF_RECORD_COMPRESSED records. $ perf report -i bt.16384.data --stats failed to decompress (B): 63869 -> 0 : Destination buffer is too small user stack dump failure Can't parse sample, err = -14 0x2637e436 [0x4080]: failed to process type: 9 Error: failed to process sample $ perf test 71 71: Zstd perf.data compression/decompression : Ok Signed-off-by:
Alexey Budankov <alexey.budankov@linux.intel.com> Acked-by:
Jiri Olsa <jolsa@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/4d839e1b-9c48-89c4-9702-a12217420611@linux.intel.comSigned-off-by:
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Cong Wang authored
The "stalled cycles per insn" is appended to "instructions" when the CPU has this hardware counter directly. We should always make it a separate line, which also aligns to the output when we hit the "if (total && avg)" branch. Before: $ sudo perf stat --all-cpus --field-separator , --log-fd 1 -einstructions,cycles -- sleep 1 4565048704,,instructions,64114578096,100.00,1.34,insn per cycle,, 3396325133,,cycles,64146628546,100.00,, After: $ sudo ./tools/perf/perf stat --all-cpus --field-separator , --log-fd 1 -einstructions,cycles -- sleep 1 6721924,,instructions,24026790339,100.00,0.22,insn per cycle ,,,,,0.00,stalled cycles per insn 30939953,,cycles,24025512526,100.00,, Signed-off-by:
Cong Wang <xiyou.wangcong@gmail.com> Acked-by:
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Jiri Olsa authored
Numfor Mbiziwo-Tiapo reported segfault on stat of event group in repeat mode: # perf stat -e '{cycles,instructions}' -r 10 ls It's caused by memory corruption due to not cleaned evsel's id array and index, which needs to be rebuilt in every stat iteration. Currently the ids index grows, while the array (which is also not freed) has the same size. Fixing this by releasing id array and zeroing ids index in perf_evsel__close function. We also need to keep the evsel_list alive for stat record (which is disabled in repeat mode). Reported-by:Numfor Mbiziwo-Tiapo <nums@google.com> Signed-off-by:
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Jiri Olsa authored
After Song Liu's segfault fix for pipe mode, Arnaldo reported following error: # perf record -o - | perf script 0x514 [0x1ac]: failed to process type: 80 It's caused by wrong buffer size setup in feature processing, which makes cpu topology feature fail, because it's using buffer size to recognize its header version. Reported-by:
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Andi Kleen authored
When we hit the end of a program block, need to count the last instruction too for the IPC computation. This caused large errors for small blocks. % perf script -b ls / > /dev/null Before: % perf script -F +brstackinsn --xed ... 00007f94c9ac70d8 jz 0x7f94c9ac70e3 # PRED 3 cycles [36] 4.33 IPC 00007f94c9ac70e3 testb $0x20, 0x31d(%rbx) 00007f94c9ac70ea jnz 0x7f94c9ac70b0 00007f94c9ac70ec testb $0x8, 0x205ad(%rip) 00007f94c9ac70f3 jz 0x7f94c9ac6ff0 # PRED 1 cycles [37] 3.00 IPC After: % perf script -F +brstackinsn --xed ... 00007f94c9ac70d8 jz 0x7f94c9ac70e3 # PRED 3 cycles [15] 4.67 IPC 00007f94c9ac70e3 testb $0x20, 0x31d(%rbx) 00007f94c9ac70ea jnz 0x7f94c9ac70b0 00007f94c9ac70ec testb $0x8, 0x205ad(%rip) 00007f94c9ac70f3 jz 0x7f94c9ac6ff0 # PRED 1 cycles [16] 4.00 IPC Suggested-by:Denis Bakhvalov <denis.bakhvalov@intel.com> Signed-off-by:
Andi Kleen <ak@linux.intel.com> Cc: Jiri Olsa <jolsa@kernel.org> Link: http://lkml.kernel.org/r/20190711181922.18765-2-andi@firstfloor.orgSigned-off-by:
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Andi Kleen authored
Clarify that a metric is based on events, not referring to itself. Also some improvements with the sentences. Signed-off-by:
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Andi Kleen authored
The --max-blocks description was using the old name brstackasm. Use brstackinsn instead. Signed-off-by:
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- 17 Jul, 2019 1 commit
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Thomas Gleixner authored
Merge tag 'perf-core-for-mingo-5.3-20190715' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo: perf db-export: Adrian Hunter: - Improvements in how COMM details are exported to databases for post processing and use in the sql-viewer.py UI. - Export switch events to the database. BPF: Arnaldo Carvalho de Melo: - Bump rlimit(MEMLOCK) for 'perf test bpf' and 'perf trace', just like selftests/bpf/bpf_rlimit.h do, which makes errors due to exhaustion of this limit, which are kinda cryptic (EPERM sometimes) less frequent. perf version: Ravi Bangoria: - Fix segfault due to missing OPT_END(), noticed on PowerPC. perf vendor events: Thomas Richter: - Add JSON files for IBM s/390 machine type 8561. perf cs-etm (ARM): YueHaibing: - Fix two cases of error returns not bing done properly: Invalid ERR_PTR() use and loss of propagation error codes.
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- 15 Jul, 2019 1 commit
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Ravi Bangoria authored
'perf version' on powerpc segfaults when used with non-supported option: # perf version -a Segmentation fault (core dumped) Fix this. Signed-off-by:
Ravi Bangoria <ravi.bangoria@linux.ibm.com> Reviewed-by:
Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Tested-by:
Mamatha Inamdar <mamatha4@linux.vnet.ibm.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/20190611030109.20228-1-ravi.bangoria@linux.ibm.comSigned-off-by:
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- 13 Jul, 2019 6 commits
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Kan Liang authored
If a user first sample a PEBS event on a fixed counter, then sample a non-PEBS event on the same fixed counter on Icelake, it will trigger spurious NMI. For example: perf record -e 'cycles:p' -a perf record -e 'cycles' -a The error message for spurious NMI: [June 21 15:38] Uhhuh. NMI received for unknown reason 30 on CPU 2. [ +0.000000] Do you have a strange power saving mode enabled? [ +0.000000] Dazed and confused, but trying to continue The bug was introduced by the following commit: commit 6f55967a ("perf/x86/intel: Fix race in intel_pmu_disable_event()") The commit moves the intel_pmu_pebs_disable() after intel_pmu_disable_fixed(), which returns immediately. The related bit of PEBS_ENABLE MSR will never be cleared for the fixed counter. Then a non-PEBS event runs on the fixed counter, but the bit on PEBS_ENABLE is still set, which triggers spurious NMIs. Check and disable PEBS for fixed counters after intel_pmu_disable_fixed(). Reported-by:
Yi, Ammy <ammy.yi@intel.com> Signed-off-by:
Kan Liang <kan.liang@linux.intel.com> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by:
Ingo Molnar <mingo@kernel.org>
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Alexander Shishkin authored
So far, we tried to disallow grouping exclusive events for the fear of complications they would cause with moving between contexts. Specifically, moving a software group to a hardware context would violate the exclusivity rules if both groups contain matching exclusive events. This attempt was, however, unsuccessful: the check that we have in the perf_event_open() syscall is both wrong (looks at wrong PMU) and insufficient (group leader may still be exclusive), as can be illustrated by running: $ perf record -e '{intel_pt//,cycles}' uname $ perf record -e '{cycles,intel_pt//}' uname ultimately successfully. Furthermore, we are completely free to trigger the exclusivity violation by: perf -e '{cycles,intel_pt//}' -e '{intel_pt//,instructions}' even though the helpful perf record will not allow that, the ABI will. The warning later in the perf_event_open() path will also not trigger, because it's also wrong. Fix all this by validating the original group before moving, getting rid of broken safeguards and placing a useful one to perf_install_in_context(). Signed-off-by:Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by:
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Kim Phillips authored
Fill in the L3 performance event select register ThreadMask bitfield, to enable per hardware thread accounting. Signed-off-by:
Kim Phillips <kim.phillips@amd.com> Signed-off-by:
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Kim Phillips authored
The following commit: d7cbbe49 ("perf/x86/amd/uncore: Set ThreadMask and SliceMask for L3 Cache perf events") enables L3 PMC events for all threads and slices by writing 1's in 'ChL3PmcCfg' (L3 PMC PERF_CTL) register fields. Those bitfields overlap with high order event select bits in the Data Fabric PMC control register, however. So when a user requests raw Data Fabric events (-e amd_df/event=0xYYY/), the two highest order bits get inadvertently set, changing the counter select to events that don't exist, and for which no counts are read. This patch changes the logic to write the L3 masks only when dealing with L3 PMC counters. AMD Family 16h and below Northbridge (NB) counters were not affected. Signed-off-by:
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Peter Zijlstra authored
Syzcaller reported the following Use-after-Free bug: close() clone() copy_process() perf_event_init_task() perf_event_init_context() mutex_lock(parent_ctx->mutex) inherit_task_group() inherit_group() inherit_event() mutex_lock(event->child_mutex) // expose event on child list list_add_tail() mutex_unlock(event->child_mutex) mutex_unlock(parent_ctx->mutex) ... goto bad_fork_* bad_fork_cleanup_perf: perf_event_free_task() perf_release() perf_event_release_kernel() list_for_each_entry() mutex_lock(ctx->mutex) mutex_lock(event->child_mutex) // event is from the failing inherit // on the other CPU perf_remove_from_context() list_move() mutex_unlock(event->child_mutex) mutex_unlock(ctx->mutex) mutex_lock(ctx->mutex) list_for_each_entry_safe() // event already stolen mutex_unlock(ctx->mutex) delayed_free_task() free_task() list_for_each_entry_safe() list_del() free_event() _free_event() // and so event->hw.target // is the already freed failed clone() if (event->hw.target) put_task_struct(event->hw.target) // WHOOPSIE, already quite dead Which puts the lie to the the comment on perf_event_free_task(): 'unexposed, unused context' not so much. Which is a 'fun' confluence of fail; copy_process() doing an unconditional free_task() and not respecting refcounts, and perf having creative locking. In particular: 82d94856 ("perf/core: Fix lock inversion between perf,trace,cpuhp") seems to have overlooked this 'fun' parade. Solve it by using the fact that detached events still have a reference count on their (previous) context. With this perf_event_free_task() can detect when events have escaped and wait for their destruction. Debugged-by:
Mark Rutland <mark.rutland@arm.com> Cc: <stable@vger.kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Fixes: 82d94856 ("perf/core: Fix lock inversion between perf,trace,cpuhp") Signed-off-by:
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Ingo Molnar authored
Merge tag 'perf-core-for-mingo-5.3-20190709' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent Pull perf/core improvements and fixes: Intel PT: Adrian Hunter: - Fix DROP VIEW power_events_view in the postgresql and sqlite export-db python scripts. perf script: Song Liu: - Assume native_arch for pipe mode, fixing a segfault. perf inject: Arnaldo Carvalho de Melo: - The tool->read() call may pass a NULL evsel, handle it. core: Arnaldo Carvalho de Melo: - Move zalloc/zfree.c to tools/lib, further eroding tools/perf/util.[ch] - Use zfree() where applicable instead of open coded equivalent. - Add stdlib.h and some other headers to places where its needed and were getting via util.h, that doesn't need that anymore. - Use list_del_init() more thoroughly. Miscellaneous: Leo Yan: - Fix use after free and potential NULL pointer derefs detected by the smatch tool in various places. Luke Mujica: - Remove a couple unused variables in the parse-events code. Numfor Mbiziwo-Tiapo: - Initialize variable to suppress memory sanitizer warning in the mmap-thread-lookup 'perf test' entry. Signed-off-by:
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- 12 Jul, 2019 24 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-coreLinus Torvalds authored
Pull driver core and debugfs updates from Greg KH: "Here is the "big" driver core and debugfs changes for 5.3-rc1 It's a lot of different patches, all across the tree due to some api changes and lots of debugfs cleanups. Other than the debugfs cleanups, in this set of changes we have: - bus iteration function cleanups - scripts/get_abi.pl tool to display and parse Documentation/ABI entries in a simple way - cleanups to Documenatation/ABI/ entries to make them parse easier due to typos and other minor things - default_attrs use for some ktype users - driver model documentation file conversions to .rst - compressed firmware file loading - deferred probe fixes All of these have been in linux-next for a while, with a bunch of merge issues that Stephen has been patient with me for" * tag 'driver-core-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (102 commits) debugfs: make error message a bit more verbose orangefs: fix build warning from debugfs cleanup patch ubifs: fix build warning after debugfs cleanup patch driver: core: Allow subsystems to continue deferring probe drivers: base: cacheinfo: Ensure cpu hotplug work is done before Intel RDT arch_topology: Remove error messages on out-of-memory conditions lib: notifier-error-inject: no need to check return value of debugfs_create functions swiotlb: no need to check return value of debugfs_create functions ceph: no need to check return value of debugfs_create functions sunrpc: no need to check return value of debugfs_create functions ubifs: no need to check return value of debugfs_create functions orangefs: no need to check return value of debugfs_create functions nfsd: no need to check return value of debugfs_create functions lib: 842: no need to check return value of debugfs_create functions debugfs: provide pr_fmt() macro debugfs: log errors when something goes wrong drivers: s390/cio: Fix compilation warning about const qualifiers drivers: Add generic helper to match by of_node driver_find_device: Unify the match function with class_find_device() bus_find_device: Unify the match callback with class_find_device ... -
Linus Torvalds authored
Merge updates from Andrew Morton: "Am experimenting with splitting MM up into identifiable subsystems perhaps with a view to gitifying it in complex ways. Also with more verbose "incoming" emails. Most of MM is here and a few other trees. Subsystems affected by this patch series: - hotfixes - iommu - scripts - arch/sh - ocfs2 - mm:slab-generic - mm:slub - mm:kmemleak - mm:kasan - mm:cleanups - mm:debug - mm:pagecache - mm:swap - mm:memcg - mm:gup - mm:pagemap - mm:infrastructure - mm:vmalloc - mm:initialization - mm:pagealloc - mm:vmscan - mm:tools - mm:proc - mm:ras - mm:oom-kill hotfixes: mm: vmscan: scan anonymous pages on file refaults mm/nvdimm: add is_ioremap_addr and use that to check ioremap address mm/memcontrol: fix wrong statistics in memory.stat mm/z3fold.c: lock z3fold page before __SetPageMovable() nilfs2: do not use unexported cpu_to_le32()/le32_to_cpu() in uapi header MAINTAINERS: nilfs2: update email address iommu: include/linux/dmar.h: replace single-char identifiers in macros scripts: scripts/decode_stacktrace: match basepath using shell prefix operator, not regex scripts/decode_stacktrace: look for modules with .ko.debug extension scripts/spelling.txt: drop "sepc" from the misspelling list scripts/spelling.txt: add spelling fix for prohibited scripts/decode_stacktrace: Accept dash/underscore in modules scripts/spelling.txt: add more spellings to spelling.txt arch/sh: arch/sh/configs/sdk7786_defconfig: remove CONFIG_LOGFS sh: config: remove left-over BACKLIGHT_LCD_SUPPORT sh: prevent warnings when using iounmap ocfs2: fs: ocfs: fix spelling mistake "hearbeating" -> "heartbeat" ocfs2/dlm: use struct_size() helper ocfs2: add last unlock times in locking_state ocfs2: add locking filter debugfs file ocfs2: add first lock wait time in locking_state ocfs: no need to check return value of debugfs_create functions fs/ocfs2/dlmglue.c: unneeded variable: "status" ocfs2: use kmemdup rather than duplicating its implementation mm:slab-generic: Patch series "mm/slab: Improved sanity checking": mm/slab: validate cache membership under freelist hardening mm/slab: sanity-check page type when looking up cache lkdtm/heap: add tests for freelist hardening mm:slub: mm/slub.c: avoid double string traverse in kmem_cache_flags() slub: don't panic for memcg kmem cache creation failure mm:kmemleak: mm/kmemleak.c: fix check for softirq context mm/kmemleak.c: change error at _write when kmemleak is disabled docs: kmemleak: add more documentation details mm:kasan: mm/kasan: print frame description for stack bugs Patch series "Bitops instrumentation for KASAN", v5: lib/test_kasan: add bitops tests x86: use static_cpu_has in uaccess region to avoid instrumentation asm-generic, x86: add bitops instrumentation for KASAN Patch series "mm/kasan: Add object validation in ksize()", v3: mm/kasan: introduce __kasan_check_{read,write} mm/kasan: change kasan_check_{read,write} to return boolean lib/test_kasan: Add test for double-kzfree detection mm/slab: refactor common ksize KASAN logic into slab_common.c mm/kasan: add object validation in ksize() mm:cleanups: include/linux/pfn_t.h: remove pfn_t_to_virt() Patch series "remove ARCH_SELECT_MEMORY_MODEL where it has no effect": arm: remove ARCH_SELECT_MEMORY_MODEL s390: remove ARCH_SELECT_MEMORY_MODEL sparc: remove ARCH_SELECT_MEMORY_MODEL mm/gup.c: make follow_page_mask() static mm/memory.c: trivial clean up in insert_page() mm: make !CONFIG_HUGE_PAGE wrappers into static inlines include/linux/mm_types.h: ifdef struct vm_area_struct::swap_readahead_info mm: remove the account_page_dirtied export mm/page_isolation.c: change the prototype of undo_isolate_page_range() include/linux/vmpressure.h: use spinlock_t instead of struct spinlock mm: remove the exporting of totalram_pages include/linux/pagemap.h: document trylock_page() return value mm:debug: mm/failslab.c: by default, do not fail allocations with direct reclaim only Patch series "debug_pagealloc improvements": mm, debug_pagelloc: use static keys to enable debugging mm, page_alloc: more extensive free page checking with debug_pagealloc mm, debug_pagealloc: use a page type instead of page_ext flag mm:pagecache: Patch series "fix filler_t callback type mismatches", v2: mm/filemap.c: fix an overly long line in read_cache_page mm/filemap: don't cast ->readpage to filler_t for do_read_cache_page jffs2: pass the correct prototype to read_cache_page 9p: pass the correct prototype to read_cache_page mm/filemap.c: correct the comment about VM_FAULT_RETRY mm:swap: mm, swap: fix race between swapoff and some swap operations mm/swap_state.c: simplify total_swapcache_pages() with get_swap_device() mm, swap: use rbtree for swap_extent mm/mincore.c: fix race between swapoff and mincore mm:memcg: memcg, oom: no oom-kill for __GFP_RETRY_MAYFAIL memcg, fsnotify: no oom-kill for remote memcg charging mm, memcg: introduce memory.events.local mm: memcontrol: dump memory.stat during cgroup OOM Patch series "mm: reparent slab memory on cgroup removal", v7: mm: memcg/slab: postpone kmem_cache memcg pointer initialization to memcg_link_cache() mm: memcg/slab: rename slab delayed deactivation functions and fields mm: memcg/slab: generalize postponed non-root kmem_cache deactivation mm: memcg/slab: introduce __memcg_kmem_uncharge_memcg() mm: memcg/slab: unify SLAB and SLUB page accounting mm: memcg/slab: don't check the dying flag on kmem_cache creation mm: memcg/slab: synchronize access to kmem_cache dying flag using a spinlock mm: memcg/slab: rework non-root kmem_cache lifecycle management mm: memcg/slab: stop setting page->mem_cgroup pointer for slab pages mm: memcg/slab: reparent memcg kmem_caches on cgroup removal mm, memcg: add a memcg_slabinfo debugfs file mm:gup: Patch series "switch the remaining architectures to use generic GUP", v4: mm: use untagged_addr() for get_user_pages_fast addresses mm: simplify gup_fast_permitted mm: lift the x86_32 PAE version of gup_get_pte to common code MIPS: use the generic get_user_pages_fast code sh: add the missing pud_page definition sh: use the generic get_user_pages_fast code sparc64: add the missing pgd_page definition sparc64: define untagged_addr() sparc64: use the generic get_user_pages_fast code mm: rename CONFIG_HAVE_GENERIC_GUP to CONFIG_HAVE_FAST_GUP mm: reorder code blocks in gup.c mm: consolidate the get_user_pages* implementations mm: validate get_user_pages_fast flags mm: move the powerpc hugepd code to mm/gup.c mm: switch gup_hugepte to use try_get_compound_head mm: mark the page referenced in gup_hugepte mm/gup: speed up check_and_migrate_cma_pages() on huge page mm/gup.c: remove some BUG_ONs from get_gate_page() mm/gup.c: mark undo_dev_pagemap as __maybe_unused mm:pagemap: asm-generic, x86: introduce generic pte_{alloc,free}_one[_kernel] alpha: switch to generic version of pte allocation arm: switch to generic version of pte allocation arm64: switch to generic version of pte allocation csky: switch to generic version of pte allocation m68k: sun3: switch to generic version of pte allocation mips: switch to generic version of pte allocation nds32: switch to generic version of pte allocation nios2: switch to generic version of pte allocation parisc: switch to generic version of pte allocation riscv: switch to generic version of pte allocation um: switch to generic version of pte allocation unicore32: switch to generic version of pte allocation mm/pgtable: drop pgtable_t variable from pte_fn_t functions mm/memory.c: fail when offset == num in first check of __vm_map_pages() mm:infrastructure: mm/mmu_notifier: use hlist_add_head_rcu() mm:vmalloc: Patch series "Some cleanups for the KVA/vmalloc", v5: mm/vmalloc.c: remove "node" argument mm/vmalloc.c: preload a CPU with one object for split purpose mm/vmalloc.c: get rid of one single unlink_va() when merge mm/vmalloc.c: switch to WARN_ON() and move it under unlink_va() mm/vmalloc.c: spelling> s/informaion/information/ mm:initialization: mm/large system hash: use vmalloc for size > MAX_ORDER when !hashdist mm/large system hash: clear hashdist when only one node with memory is booted mm:pagealloc: arm64: move jump_label_init() before parse_early_param() Patch series "add init_on_alloc/init_on_free boot options", v10: mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options mm: init: report memory auto-initialization features at boot time mm:vmscan: mm: vmscan: remove double slab pressure by inc'ing sc->nr_scanned mm: vmscan: correct some vmscan counters for THP swapout mm:tools: tools/vm/slabinfo: order command line options tools/vm/slabinfo: add partial slab listing to -X tools/vm/slabinfo: add option to sort by partial slabs tools/vm/slabinfo: add sorting info to help menu mm:proc: proc: use down_read_killable mmap_sem for /proc/pid/maps proc: use down_read_killable mmap_sem for /proc/pid/smaps_rollup proc: use down_read_killable mmap_sem for /proc/pid/pagemap proc: use down_read_killable mmap_sem for /proc/pid/clear_refs proc: use down_read_killable mmap_sem for /proc/pid/map_files mm: use down_read_killable for locking mmap_sem in access_remote_vm mm: smaps: split PSS into components mm: vmalloc: show number of vmalloc pages in /proc/meminfo mm:ras: mm/memory-failure.c: clarify error message mm:oom-kill: mm: memcontrol: use CSS_TASK_ITER_PROCS at mem_cgroup_scan_tasks() mm, oom: refactor dump_tasks for memcg OOMs mm, oom: remove redundant task_in_mem_cgroup() check oom: decouple mems_allowed from oom_unkillable_task mm/oom_kill.c: remove redundant OOM score normalization in select_bad_process()" * akpm: (147 commits) mm/oom_kill.c: remove redundant OOM score normalization in select_bad_process() oom: decouple mems_allowed from oom_unkillable_task mm, oom: remove redundant task_in_mem_cgroup() check mm, oom: refactor dump_tasks for memcg OOMs mm: memcontrol: use CSS_TASK_ITER_PROCS at mem_cgroup_scan_tasks() mm/memory-failure.c: clarify error message mm: vmalloc: show number of vmalloc pages in /proc/meminfo mm: smaps: split PSS into components mm: use down_read_killable for locking mmap_sem in access_remote_vm proc: use down_read_killable mmap_sem for /proc/pid/map_files proc: use down_read_killable mmap_sem for /proc/pid/clear_refs proc: use down_read_killable mmap_sem for /proc/pid/pagemap proc: use down_read_killable mmap_sem for /proc/pid/smaps_rollup proc: use down_read_killable mmap_sem for /proc/pid/maps tools/vm/slabinfo: add sorting info to help menu tools/vm/slabinfo: add option to sort by partial slabs tools/vm/slabinfo: add partial slab listing to -X tools/vm/slabinfo: order command line options mm: vmscan: correct some vmscan counters for THP swapout mm: vmscan: remove double slab pressure by inc'ing sc->nr_scanned ... -
Tetsuo Handa authored
Since commit bbbe4802 ("mm, oom: remove 'prefer children over parent' heuristic") removed the "%s: Kill process %d (%s) score %u or sacrifice child\n" line, oc->chosen_points is no longer used after select_bad_process(). Link: http://lkml.kernel.org/r/1560853435-15575-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jpSigned-off-by:
Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by:
Michal Hocko <mhocko@suse.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Roman Gushchin <guro@fb.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Shakeel Butt authored
Commit ef08e3b4 ("[PATCH] cpusets: confine oom_killer to mem_exclusive cpuset") introduces a heuristic where a potential oom-killer victim is skipped if the intersection of the potential victim and the current (the process triggered the oom) is empty based on the reason that killing such victim most probably will not help the current allocating process. However the commit 7887a3da ("[PATCH] oom: cpuset hint") changed the heuristic to just decrease the oom_badness scores of such potential victim based on the reason that the cpuset of such processes might have changed and previously they may have allocated memory on mems where the current allocating process can allocate from. Unintentionally 7887a3da ("[PATCH] oom: cpuset hint") introduced a side effect as the oom_badness is also exposed to the user space through /proc/[pid]/oom_score, so, readers with different cpusets can read different oom_score of the same process. Later, commit 6cf86ac6 ("oom: filter tasks not sharing the same cpuset") fixed the side effect introduced by 7887a3da by moving the cpuset intersection back to only oom-killer context and out of oom_badness. However the combination of ab290adb ("oom: make oom_unkillable_task() helper function") and 26ebc984 ("oom: /proc/<pid>/oom_score treat kernel thread honestly") unintentionally brought back the cpuset intersection check into the oom_badness calculation function. Other than doing cpuset/mempolicy intersection from oom_badness, the memcg oom context is also doing cpuset/mempolicy intersection which is quite wrong and is caught by syzcaller with the following report: kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 28426 Comm: syz-executor.5 Not tainted 5.2.0-rc3-next-20190607 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__read_once_size include/linux/compiler.h:194 [inline] RIP: 0010:has_intersects_mems_allowed mm/oom_kill.c:84 [inline] RIP: 0010:oom_unkillable_task mm/oom_kill.c:168 [inline] RIP: 0010:oom_unkillable_task+0x180/0x400 mm/oom_kill.c:155 Code: c1 ea 03 80 3c 02 00 0f 85 80 02 00 00 4c 8b a3 10 07 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8d 74 24 10 4c 89 f2 48 c1 ea 03 <80> 3c 02 00 0f 85 67 02 00 00 49 8b 44 24 10 4c 8d a0 68 fa ff ff RSP: 0018:ffff888000127490 EFLAGS: 00010a03 RAX: dffffc0000000000 RBX: ffff8880a4cd5438 RCX: ffffffff818dae9c RDX: 100000000c3cc602 RSI: ffffffff818dac8d RDI: 0000000000000001 RBP: ffff8880001274d0 R08: ffff888000086180 R09: ffffed1015d26be0 R10: ffffed1015d26bdf R11: ffff8880ae935efb R12: 8000000061e63007 R13: 0000000000000000 R14: 8000000061e63017 R15: 1ffff11000024ea6 FS: 00005555561f5940(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000607304 CR3: 000000009237e000 CR4: 00000000001426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: oom_evaluate_task+0x49/0x520 mm/oom_kill.c:321 mem_cgroup_scan_tasks+0xcc/0x180 mm/memcontrol.c:1169 select_bad_process mm/oom_kill.c:374 [inline] out_of_memory mm/oom_kill.c:1088 [inline] out_of_memory+0x6b2/0x1280 mm/oom_kill.c:1035 mem_cgroup_out_of_memory+0x1ca/0x230 mm/memcontrol.c:1573 mem_cgroup_oom mm/memcontrol.c:1905 [inline] try_charge+0xfbe/0x1480 mm/memcontrol.c:2468 mem_cgroup_try_charge+0x24d/0x5e0 mm/memcontrol.c:6073 mem_cgroup_try_charge_delay+0x1f/0xa0 mm/memcontrol.c:6088 do_huge_pmd_wp_page_fallback+0x24f/0x1680 mm/huge_memory.c:1201 do_huge_pmd_wp_page+0x7fc/0x2160 mm/huge_memory.c:1359 wp_huge_pmd mm/memory.c:3793 [inline] __handle_mm_fault+0x164c/0x3eb0 mm/memory.c:4006 handle_mm_fault+0x3b7/0xa90 mm/memory.c:4053 do_user_addr_fault arch/x86/mm/fault.c:1455 [inline] __do_page_fault+0x5ef/0xda0 arch/x86/mm/fault.c:1521 do_page_fault+0x71/0x57d arch/x86/mm/fault.c:1552 page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1156 RIP: 0033:0x400590 Code: 06 e9 49 01 00 00 48 8b 44 24 10 48 0b 44 24 28 75 1f 48 8b 14 24 48 8b 7c 24 20 be 04 00 00 00 e8 f5 56 00 00 48 8b 74 24 08 <89> 06 e9 1e 01 00 00 48 8b 44 24 08 48 8b 14 24 be 04 00 00 00 8b RSP: 002b:00007fff7bc49780 EFLAGS: 00010206 RAX: 0000000000000001 RBX: 0000000000760000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 000000002000cffc RDI: 0000000000000001 RBP: fffffffffffffffe R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000760008 R13: 00000000004c55f2 R14: 0000000000000000 R15: 00007fff7bc499b0 Modules linked in: ---[ end trace a65689219582ffff ]--- RIP: 0010:__read_once_size include/linux/compiler.h:194 [inline] RIP: 0010:has_intersects_mems_allowed mm/oom_kill.c:84 [inline] RIP: 0010:oom_unkillable_task mm/oom_kill.c:168 [inline] RIP: 0010:oom_unkillable_task+0x180/0x400 mm/oom_kill.c:155 Code: c1 ea 03 80 3c 02 00 0f 85 80 02 00 00 4c 8b a3 10 07 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8d 74 24 10 4c 89 f2 48 c1 ea 03 <80> 3c 02 00 0f 85 67 02 00 00 49 8b 44 24 10 4c 8d a0 68 fa ff ff RSP: 0018:ffff888000127490 EFLAGS: 00010a03 RAX: dffffc0000000000 RBX: ffff8880a4cd5438 RCX: ffffffff818dae9c RDX: 100000000c3cc602 RSI: ffffffff818dac8d RDI: 0000000000000001 RBP: ffff8880001274d0 R08: ffff888000086180 R09: ffffed1015d26be0 R10: ffffed1015d26bdf R11: ffff8880ae935efb R12: 8000000061e63007 R13: 0000000000000000 R14: 8000000061e63017 R15: 1ffff11000024ea6 FS: 00005555561f5940(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2f823000 CR3: 000000009237e000 CR4: 00000000001426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 The fix is to decouple the cpuset/mempolicy intersection check from oom_unkillable_task() and make sure cpuset/mempolicy intersection check is only done in the global oom context. [shakeelb@google.com: change function name and update comment] Link: http://lkml.kernel.org/r/20190628152421.198994-3-shakeelb@google.com Link: http://lkml.kernel.org/r/20190624212631.87212-3-shakeelb@google.comSigned-off-by:
Shakeel Butt <shakeelb@google.com> Reported-by: syzbot+d0fc9d3c166bc5e4a94b@syzkaller.appspotmail.com Acked-by:
Roman Gushchin <guro@fb.com> Acked-by:
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Shakeel Butt authored
oom_unkillable_task() can be called from three different contexts i.e. global OOM, memcg OOM and oom_score procfs interface. At the moment oom_unkillable_task() does a task_in_mem_cgroup() check on the given process. Since there is no reason to perform task_in_mem_cgroup() check for global OOM and oom_score procfs interface, those contexts provide NULL memcg and skips the task_in_mem_cgroup() check. However for memcg OOM context, the oom_unkillable_task() is always called from mem_cgroup_scan_tasks() and thus task_in_mem_cgroup() check becomes redundant and effectively dead code. So, just remove the task_in_mem_cgroup() check altogether. Link: http://lkml.kernel.org/r/20190624212631.87212-2-shakeelb@google.comSigned-off-by:
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Shakeel Butt authored
dump_tasks() traverses all the existing processes even for the memcg OOM context which is not only unnecessary but also wasteful. This imposes a long RCU critical section even from a contained context which can be quite disruptive. Change dump_tasks() to be aligned with select_bad_process and use mem_cgroup_scan_tasks to selectively traverse only processes of the target memcg hierarchy during memcg OOM. Link: http://lkml.kernel.org/r/20190617231207.160865-1-shakeelb@google.comSigned-off-by:
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Tetsuo Handa authored
Since commit c03cd773 ("cgroup: Include dying leaders with live threads in PROCS iterations") corrected how CSS_TASK_ITER_PROCS works, mem_cgroup_scan_tasks() can use CSS_TASK_ITER_PROCS in order to check only one thread from each thread group. [penguin-kernel@I-love.SAKURA.ne.jp: remove thread group leader check in oom_evaluate_task()] Link: http://lkml.kernel.org/r/1560853257-14934-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp Link: http://lkml.kernel.org/r/c763afc8-f0ae-756a-56a7-395f625b95fc@i-love.sakura.ne.jpSigned-off-by:
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Jane Chu authored
Some user who install SIGBUS handler that does longjmp out therefore keeping the process alive is confused by the error message "[188988.765862] Memory failure: 0x1840200: Killing cellsrv:33395 due to hardware memory corruption" Slightly modify the error message to improve clarity. Link: http://lkml.kernel.org/r/1558403523-22079-1-git-send-email-jane.chu@oracle.comSigned-off-by:
Jane Chu <jane.chu@oracle.com> Acked-by:
Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by:
Pankaj Gupta <pagupta@redhat.com> Reviewed-by:
Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by:
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Roman Gushchin authored
Vmalloc() is getting more and more used these days (kernel stacks, bpf and percpu allocator are new top users), and the total % of memory consumed by vmalloc() can be pretty significant and changes dynamically. /proc/meminfo is the best place to display this information: its top goal is to show top consumers of the memory. Since the VmallocUsed field in /proc/meminfo is not in use for quite a long time (it has been defined to 0 by a5ad88ce ("mm: get rid of 'vmalloc_info' from /proc/meminfo")), let's reuse it for showing the actual physical memory consumption of vmalloc(). Link: http://lkml.kernel.org/r/20190417194002.12369-3-guro@fb.comSigned-off-by:
Johannes Weiner <hannes@cmpxchg.org> Acked-by:
Vlastimil Babka <vbabka@suse.cz> Reviewed-by:
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Luigi Semenzato authored
Report separate components (anon, file, and shmem) for PSS in smaps_rollup. This helps understand and tune the memory manager behavior in consumer devices, particularly mobile devices. Many of them (e.g. chromebooks and Android-based devices) use zram for anon memory, and perform disk reads for discarded file pages. The difference in latency is large (e.g. reading a single page from SSD is 30 times slower than decompressing a zram page on one popular device), thus it is useful to know how much of the PSS is anon vs. file. All the information is already present in /proc/pid/smaps, but much more expensive to obtain because of the large size of that procfs entry. This patch also removes a small code duplication in smaps_account, which would have gotten worse otherwise. Also updated Documentation/filesystems/proc.txt (the smaps section was a bit stale, and I added a smaps_rollup section) and Documentation/ABI/testing/procfs-smaps_rollup. [semenzato@chromium.org: v5] Link: http://lkml.kernel.org/r/20190626234333.44608-1-semenzato@chromium.org Link: http://lkml.kernel.org/r/20190626180429.174569-1-semenzato@chromium.orgSigned-off-by:
Luigi Semenzato <semenzato@chromium.org> Acked-by:
Yu Zhao <yuzhao@chromium.org> Cc: Sonny Rao <sonnyrao@chromium.org> Cc: Yu Zhao <yuzhao@chromium.org> Cc: Brian Geffon <bgeffon@chromium.org> Signed-off-by:
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Konstantin Khlebnikov authored
This function is used by ptrace and proc files like /proc/pid/cmdline and /proc/pid/environ. Access_remote_vm never returns error codes, all errors are ignored and only size of successfully read data is returned. So, if current task was killed we'll simply return 0 (bytes read). Mmap_sem could be locked for a long time or forever if something goes wrong. Using a killable lock permits cleanup of stuck tasks and simplifies investigation. Link: http://lkml.kernel.org/r/156007494202.3335.16782303099589302087.stgit@buzzSigned-off-by:
Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Reviewed-by:
Michal Koutný <mkoutny@suse.com> Acked-by:
Oleg Nesterov <oleg@redhat.com> Acked-by:
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Konstantin Khlebnikov authored
Do not remain stuck forever if something goes wrong. Using a killable lock permits cleanup of stuck tasks and simplifies investigation. It seems ->d_revalidate() could return any error (except ECHILD) to abort validation and pass error as result of lookup sequence. [akpm@linux-foundation.org: fix proc_map_files_lookup() return value, per Andrei] Link: http://lkml.kernel.org/r/156007493995.3335.9595044802115356911.stgit@buzzSigned-off-by:
Cyrill Gorcunov <gorcunov@gmail.com> Reviewed-by:
Kirill Tkhai <ktkhai@virtuozzo.com> Acked-by:
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Konstantin Khlebnikov authored
Do not remain stuck forever if something goes wrong. Using a killable lock permits cleanup of stuck tasks and simplifies investigation. Replace the only unkillable mmap_sem lock in clear_refs_write(). Link: http://lkml.kernel.org/r/156007493826.3335.5424884725467456239.stgit@buzzSigned-off-by:
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Konstantin Khlebnikov authored
Do not remain stuck forever if something goes wrong. Using a killable lock permits cleanup of stuck tasks and simplifies investigation. Link: http://lkml.kernel.org/r/156007493638.3335.4872164955523928492.stgit@buzzSigned-off-by:
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Konstantin Khlebnikov authored
Do not remain stuck forever if something goes wrong. Using a killable lock permits cleanup of stuck tasks and simplifies investigation. Link: http://lkml.kernel.org/r/156007493429.3335.14666825072272692455.stgit@buzzSigned-off-by:
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Konstantin Khlebnikov authored
Do not remain stuck forever if something goes wrong. Using a killable lock permits cleanup of stuck tasks and simplifies investigation. This function is also used for /proc/pid/smaps. Link: http://lkml.kernel.org/r/156007493160.3335.14447544314127417266.stgit@buzzSigned-off-by:
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Tobin C. Harding authored
Passing more than one sorting option has undefined behaviour. Add an explicit statement as such to the help menu, this also has the advantage of highlighting all the sorting options. Link: http://lkml.kernel.org/r/20190426022622.4089-5-tobin@kernel.orgSigned-off-by:
Tobin C. Harding <tobin@kernel.org> Cc: Alexander Duyck <alexander.duyck@gmail.com> Cc: Brendan Gregg <brendan.d.gregg@gmail.com>, Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: Pekka Enberg <penberg@iki.fi> Cc: Qian Cai <cai@lca.pw> Cc: Tejun Heo <tj@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by:
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Tobin C. Harding authored
We would like to get a better view of the level of fragmentation within the SLUB allocator. Total number of partial slabs is an indicator of fragmentation. Add a command line option (-P | --partial) to sort the slab list by total number of partial slabs. Link: http://lkml.kernel.org/r/20190426022622.4089-4-tobin@kernel.orgSigned-off-by:
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Tobin C. Harding authored
We would like to see how fragmented the SLUB allocator is, one window into fragmentation is the total number of partial slabs. Currently `slabinfo -X` shows slabs sorted by loss and by size. We can use this option to also show slabs sorted by number of partial slabs. Option '-X' can be used in conjunction with '-N' to control the number of slabs shown e.g. list of top 5 slabs: slabinfo -X -N5 Add list of slabs ordered by number of partial slabs to output of `slabinfo -X`. Link: http://lkml.kernel.org/r/20190426022622.4089-3-tobin@kernel.orgSigned-off-by:
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Tobin C. Harding authored
During recent discussion on LKML over SLAB vs SLUB it was suggested by Jesper that it would be nice to have a tool to view the current fragmentation of the slab allocators. CC list for this set is taken from that thread. For SLUB we have all the information for this already exposed by the kernel and also we have a userspace tool for displaying this info: tools/vm/slabinfo.c Extend slabinfo to improve the fragmentation information by enabling sorting of caches by number of partial slabs. Also add cache list sorted in this manner to the output of `slabinfo -X`. This patch (of 4): get_opt() has a spurious character within the option string. Remove it and reorder the options in alphabetic order so that it is easier to keep the options correct. Use the same ordering for command help output and long option handling code. Link: http://lkml.kernel.org/r/20190426022622.4089-2-tobin@kernel.orgSigned-off-by:
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Yang Shi authored
Commit bd4c82c2 ("mm, THP, swap: delay splitting THP after swapped out"), THP can be swapped out in a whole. But, nr_reclaimed and some other vm counters still get inc'ed by one even though a whole THP (512 pages) gets swapped out. This doesn't make too much sense to memory reclaim. For example, direct reclaim may just need reclaim SWAP_CLUSTER_MAX pages, reclaiming one THP could fulfill it. But, if nr_reclaimed is not increased correctly, direct reclaim may just waste time to reclaim more pages, SWAP_CLUSTER_MAX * 512 pages in worst case. And, it may cause pgsteal_{kswapd|direct} is greater than pgscan_{kswapd|direct}, like the below: pgsteal_kswapd 122933 pgsteal_direct 26600225 pgscan_kswapd 174153 pgscan_direct 14678312 nr_reclaimed and nr_scanned must be fixed in parallel otherwise it would break some page reclaim logic, e.g. vmpressure: this looks at the scanned/reclaimed ratio so it won't change semantics as long as scanned & reclaimed are fixed in parallel. compaction/reclaim: compaction wants a certain number of physical pages freed up before going back to compacting. kswapd priority raising: kswapd raises priority if we scan fewer pages than the reclaim target (which itself is obviously expressed in order-0 pages). As a result, kswapd can falsely raise its aggressiveness even when it's making great progress. Other than nr_scanned and nr_reclaimed, some other counters, e.g. pgactivate, nr_skipped, nr_ref_keep and nr_unmap_fail need to be fixed too since they are user visible via cgroup, /proc/vmstat or trace points, otherwise they would be underreported. When isolating pages from LRUs, nr_taken has been accounted in base page, but nr_scanned and nr_skipped are still accounted in THP. It doesn't make too much sense too since this may cause trace point underreport the numbers as well. So accounting those counters in base page instead of accounting THP as one page. nr_dirty, nr_unqueued_dirty, nr_congested and nr_writeback are used by file cache, so they are not impacted by THP swap. This change may result in lower steal/scan ratio in some cases since THP may get split during page reclaim, then a part of tail pages get reclaimed instead of the whole 512 pages, but nr_scanned is accounted by 512, particularly for direct reclaim. But, this should be not a significant issue. Link: http://lkml.kernel.org/r/1559025859-72759-2-git-send-email-yang.shi@linux.alibaba.comSigned-off-by:
Yang Shi <yang.shi@linux.alibaba.com> Reviewed-by:
"Huang, Ying" <ying.huang@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by:
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Yang Shi authored
Commit 9092c71b ("mm: use sc->priority for slab shrink targets") has broken up the relationship between sc->nr_scanned and slab pressure. The sc->nr_scanned can't double slab pressure anymore. So, it sounds no sense to still keep sc->nr_scanned inc'ed. Actually, it would prevent from adding pressure on slab shrink since excessive sc->nr_scanned would prevent from scan->priority raise. The bonnie test doesn't show this would change the behavior of slab shrinkers. w/ w/o /sec %CP /sec %CP Sequential delete: 3960.6 94.6 3997.6 96.2 Random delete: 2518 63.8 2561.6 64.6 The slight increase of "/sec" without the patch would be caused by the slight increase of CPU usage. Link: http://lkml.kernel.org/r/1559025859-72759-1-git-send-email-yang.shi@linux.alibaba.comSigned-off-by:
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Alexander Potapenko authored
Print the currently enabled stack and heap initialization modes. Stack initialization is enabled by a config flag, while heap initialization is configured at boot time with defaults being set in the config. It's more convenient for the user to have all information about these hardening measures in one place at boot, so the user can reason about the expected behavior of the running system. The possible options for stack are: - "all" for CONFIG_INIT_STACK_ALL; - "byref_all" for CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL; - "byref" for CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF; - "__user" for CONFIG_GCC_PLUGIN_STRUCTLEAK_USER; - "off" otherwise. Depending on the values of init_on_alloc and init_on_free boottime options we also report "heap alloc" and "heap free" as "on"/"off". In the init_on_free mode initializing pages at boot time may take a while, so print a notice about that as well. This depends on how much memory is installed, the memory bandwidth, etc. On a relatively modern x86 system, it takes about 0.75s/GB to wipe all memory: [ 0.418722] mem auto-init: stack:byref_all, heap alloc:off, heap free:on [ 0.419765] mem auto-init: clearing system memory may take some time... [ 12.376605] Memory: 16408564K/16776672K available (14339K kernel code, 1397K rwdata, 3756K rodata, 1636K init, 11460K bss, 368108K reserved, 0K cma-reserved) Link: http://lkml.kernel.org/r/20190617151050.92663-3-glider@google.comSigned-off-by:
Alexander Potapenko <glider@google.com> Suggested-by:
Kees Cook <keescook@chromium.org> Acked-by:
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Alexander Potapenko authored
Patch series "add init_on_alloc/init_on_free boot options", v10. Provide init_on_alloc and init_on_free boot options. These are aimed at preventing possible information leaks and making the control-flow bugs that depend on uninitialized values more deterministic. Enabling either of the options guarantees that the memory returned by the page allocator and SL[AU]B is initialized with zeroes. SLOB allocator isn't supported at the moment, as its emulation of kmem caches complicates handling of SLAB_TYPESAFE_BY_RCU caches correctly. Enabling init_on_free also guarantees that pages and heap objects are initialized right after they're freed, so it won't be possible to access stale data by using a dangling pointer. As suggested by Michal Hocko, right now we don't let the heap users to disable initialization for certain allocations. There's not enough evidence that doing so can speed up real-life cases, and introducing ways to opt-out may result in things going out of control. This patch (of 2): The new options are needed to prevent possible information leaks and make control-flow bugs that depend on uninitialized values more deterministic. This is expected to be on-by-default on Android and Chrome OS. And it gives the opportunity for anyone else to use it under distros too via the boot args. (The init_on_free feature is regularly requested by folks where memory forensics is included in their threat models.) init_on_alloc=1 makes the kernel initialize newly allocated pages and heap objects with zeroes. Initialization is done at allocation time at the places where checks for __GFP_ZERO are performed. init_on_free=1 makes the kernel initialize freed pages and heap objects with zeroes upon their deletion. This helps to ensure sensitive data doesn't leak via use-after-free accesses. Both init_on_alloc=1 and init_on_free=1 guarantee that the allocator returns zeroed memory. The two exceptions are slab caches with constructors and SLAB_TYPESAFE_BY_RCU flag. Those are never zero-initialized to preserve their semantics. Both init_on_alloc and init_on_free default to zero, but those defaults can be overridden with CONFIG_INIT_ON_ALLOC_DEFAULT_ON and CONFIG_INIT_ON_FREE_DEFAULT_ON. If either SLUB poisoning or page poisoning is enabled, those options take precedence over init_on_alloc and init_on_free: initialization is only applied to unpoisoned allocations. Slowdown for the new features compared to init_on_free=0, init_on_alloc=0: hackbench, init_on_free=1: +7.62% sys time (st.err 0.74%) hackbench, init_on_alloc=1: +7.75% sys time (st.err 2.14%) Linux build with -j12, init_on_free=1: +8.38% wall time (st.err 0.39%) Linux build with -j12, init_on_free=1: +24.42% sys time (st.err 0.52%) Linux build with -j12, init_on_alloc=1: -0.13% wall time (st.err 0.42%) Linux build with -j12, init_on_alloc=1: +0.57% sys time (st.err 0.40%) The slowdown for init_on_free=0, init_on_alloc=0 compared to the baseline is within the standard error. The new features are also going to pave the way for hardware memory tagging (e.g. arm64's MTE), which will require both on_alloc and on_free hooks to set the tags for heap objects. With MTE, tagging will have the same cost as memory initialization. Although init_on_free is rather costly, there are paranoid use-cases where in-memory data lifetime is desired to be minimized. There are various arguments for/against the realism of the associated threat models, but given that we'll need the infrastructure for MTE anyway, and there are people who want wipe-on-free behavior no matter what the performance cost, it seems reasonable to include it in this series. [glider@google.com: v8] Link: http://lkml.kernel.org/r/20190626121943.131390-2-glider@google.com [glider@google.com: v9] Link: http://lkml.kernel.org/r/20190627130316.254309-2-glider@google.com [glider@google.com: v10] Link: http://lkml.kernel.org/r/20190628093131.199499-2-glider@google.com Link: http://lkml.kernel.org/r/20190617151050.92663-2-glider@google.comSigned-off-by:
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