kernel/include/trace/events/kmem.h, branch linux-5.11.y

mm, tracing: print symbol name for kmem_alloc_node call_site events

2020-01-31T18:30:38Z

Print the call_site ip of kmem_alloc_node using '%pS' to improve the readability of raw slab trace points. Link: http://lkml.kernel.org/r/1577949568-4518-1-git-send-email-sunjunyong@xiaomi.com Signed-off-by: Junyong Sun Acked-by: Steven Rostedt (VMware) Cc: Ingo Molnar Cc: Joel Fernandes (Google) Cc: Changbin Du Cc: Tim Murray Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

rss_stat: add support to detect RSS updates of external mm

2019-12-01T14:29:18Z

When a process updates the RSS of a different process, the rss_stat tracepoint appears in the context of the process doing the update. This can confuse userspace that the RSS of process doing the update is updated, while in reality a different process's RSS was updated. This issue happens in reclaim paths such as with direct reclaim or background reclaim. This patch adds more information to the tracepoint about whether the mm being updated belongs to the current process's context (curr field). We also include a hash of the mm pointer so that the process who the mm belongs to can be uniquely identified (mm_id field). Also vsprintf.c is refactored a bit to allow reuse of hashing code. [akpm@linux-foundation.org: remove unused local `str'] [joelaf@google.com: inline call to ptr_to_hashval] Link: http://lore.kernel.org/r/20191113153816.14b95acd@gandalf.local.home Link: http://lkml.kernel.org/r/20191114164622.GC233237@google.com Link: http://lkml.kernel.org/r/20191106024452.81923-1-joel@joelfernandes.org Signed-off-by: Joel Fernandes (Google) Reported-by: Ioannis Ilkos Acked-by: Petr Mladek [lib/vsprintf.c] Cc: Tim Murray Cc: Michal Hocko Cc: Carmen Jackson Cc: Mayank Gupta Cc: Daniel Colascione Cc: Steven Rostedt (VMware) Cc: Minchan Kim Cc: "Aneesh Kumar K.V" Cc: Dan Williams Cc: Jerome Glisse Cc: Matthew Wilcox Cc: Ralph Campbell Cc: Vlastimil Babka Cc: Steven Rostedt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: emit tracepoint when RSS changes

2019-12-01T14:29:18Z

Useful to track how RSS is changing per TGID to detect spikes in RSS and memory hogs. Several Android teams have been using this patch in various kernel trees for half a year now. Many reported to me it is really useful so I'm posting it upstream. Initial patch developed by Tim Murray. Changes I made from original patch: o Prevent any additional space consumed by mm_struct. Regarding the fact that the RSS may change too often thus flooding the traces - note that, there is some "hysterisis" with this already. That is - We update the counter only if we receive 64 page faults due to SPLIT_RSS_ACCOUNTING. However, during zapping or copying of pte range, the RSS is updated immediately which can become noisy/flooding. In a previous discussion, we agreed that BPF or ftrace can be used to rate limit the signal if this becomes an issue. Also note that I added wrappers to trace_rss_stat to prevent compiler errors where linux/mm.h is included from tracing code, causing errors such as: CC kernel/trace/power-traces.o In file included from ./include/trace/define_trace.h:102, from ./include/trace/events/kmem.h:342, from ./include/linux/mm.h:31, from ./include/linux/ring_buffer.h:5, from ./include/linux/trace_events.h:6, from ./include/trace/events/power.h:12, from kernel/trace/power-traces.c:15: ./include/trace/trace_events.h:113:22: error: field `ent' has incomplete type struct trace_entry ent; \ Link: http://lore.kernel.org/r/20190903200905.198642-1-joel@joelfernandes.org Link: http://lkml.kernel.org/r/20191001172817.234886-1-joel@joelfernandes.org Co-developed-by: Tim Murray Signed-off-by: Tim Murray Signed-off-by: Joel Fernandes (Google) Acked-by: Michal Hocko Cc: Carmen Jackson Cc: Mayank Gupta Cc: Daniel Colascione Cc: Steven Rostedt (VMware) Cc: Minchan Kim Cc: "Aneesh Kumar K.V" Cc: Dan Williams Cc: Jerome Glisse Cc: Matthew Wilcox Cc: Ralph Campbell Cc: Vlastimil Babka Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm, tracing: Print symbol name for call_site in trace events

2019-09-28T21:13:39Z

To improve the readability of raw slab trace points, print the call_site ip using '%pS'. Then we can grep events with function names. [002] .... 808.188897: kmem_cache_free: call_site=putname+0x47/0x50 ptr=00000000cef40c80 [002] .... 808.188898: kfree: call_site=security_cred_free+0x42/0x50 ptr=0000000062400820 [002] .... 808.188904: kmem_cache_free: call_site=put_cred_rcu+0x88/0xa0 ptr=0000000058d74ef8 [002] .... 808.188913: kmem_cache_alloc: call_site=prepare_creds+0x26/0x100 ptr=0000000058d74ef8 bytes_req=168 bytes_alloc=576 gfp_flags=GFP_KERNEL [002] .... 808.188917: kmalloc: call_site=security_prepare_creds+0x77/0xa0 ptr=0000000062400820 bytes_req=8 bytes_alloc=336 gfp_flags=GFP_KERNEL|__GFP_ZERO [002] .... 808.188920: kmem_cache_alloc: call_site=getname_flags+0x4f/0x1e0 ptr=00000000cef40c80 bytes_req=4096 bytes_alloc=4480 gfp_flags=GFP_KERNEL [002] .... 808.188925: kmem_cache_free: call_site=putname+0x47/0x50 ptr=00000000cef40c80 [002] .... 808.188926: kfree: call_site=security_cred_free+0x42/0x50 ptr=0000000062400820 [002] .... 808.188931: kmem_cache_free: call_site=put_cred_rcu+0x88/0xa0 ptr=0000000058d74ef8 Link: http://lkml.kernel.org/r/20190914103215.23301-1-changbin.du@gmail.com Signed-off-by: Changbin Du Signed-off-by: Steven Rostedt (VMware)

mm: remove cold parameter from free_hot_cold_page*

2017-11-16T02:21:06Z

Most callers users of free_hot_cold_page claim the pages being released are cache hot. The exception is the page reclaim paths where it is likely that enough pages will be freed in the near future that the per-cpu lists are going to be recycled and the cache hotness information is lost. As no one really cares about the hotness of pages being released to the allocator, just ditch the parameter. The APIs are renamed to indicate that it's no longer about hot/cold pages. It should also be less confusing as there are subtle differences between them. __free_pages drops a reference and frees a page when the refcount reaches zero. free_hot_cold_page handled pages whose refcount was already zero which is non-obvious from the name. free_unref_page should be more obvious. No performance impact is expected as the overhead is marginal. The parameter is removed simply because it is a bit stupid to have a useless parameter copied everywhere. [mgorman@techsingularity.net: add pages to head, not tail] Link: http://lkml.kernel.org/r/20171019154321.qtpzaeftoyyw4iey@techsingularity.net Link: http://lkml.kernel.org/r/20171018075952.10627-8-mgorman@techsingularity.net Signed-off-by: Mel Gorman Acked-by: Vlastimil Babka Cc: Andi Kleen Cc: Dave Chinner Cc: Dave Hansen Cc: Jan Kara Cc: Johannes Weiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55Z

Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

Merge tag 'trace-v4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2016-03-24T17:52:25Z

Pull tracing updates from Steven Rostedt: "Nothing major this round. Mostly small clean ups and fixes. Some visible changes: - A new flag was added to distinguish traces done in NMI context. - Preempt tracer now shows functions where preemption is disabled but interrupts are still enabled. Other notes: - Updates were done to function tracing to allow better performance with perf. - Infrastructure code has been added to allow for a new histogram feature for recording live trace event histograms that can be configured by simple user commands. The feature itself was just finished, but needs a round in linux-next before being pulled. This only includes some infrastructure changes that will be needed" * tag 'trace-v4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (22 commits) tracing: Record and show NMI state tracing: Fix trace_printk() to print when not using bprintk() tracing: Remove redundant reset per-CPU buff in irqsoff tracer x86: ftrace: Fix the misleading comment for arch/x86/kernel/ftrace.c tracing: Fix crash from reading trace_pipe with sendfile tracing: Have preempt(irqs)off trace preempt disabled functions tracing: Fix return while holding a lock in register_tracer() ftrace: Use kasprintf() in ftrace_profile_tracefs() ftrace: Update dynamic ftrace calls only if necessary ftrace: Make ftrace_hash_rec_enable return update bool tracing: Fix typoes in code comment and printk in trace_nop.c tracing, writeback: Replace cgroup path to cgroup ino tracing: Use flags instead of bool in trigger structure tracing: Add an unreg_all() callback to trigger commands tracing: Add needs_rec flag to event triggers tracing: Add a per-event-trigger 'paused' field tracing: Add get_syscall_name() tracing: Add event record param to trigger_ops.func() tracing: Make event trigger functions available tracing: Make ftrace_event_field checking functions available ...

mm, tracing: unify mm flags handling in tracepoints and printk

2016-03-15T23:55:16Z

In tracepoints, it's possible to print gfp flags in a human-friendly format through a macro show_gfp_flags(), which defines a translation array and passes is to __print_flags(). Since the following patch will introduce support for gfp flags printing in printk(), it would be nice to reuse the array. This is not straightforward, since __print_flags() can't simply reference an array defined in a .c file such as mm/debug.c - it has to be a macro to allow the macro magic to communicate the format to userspace tools such as trace-cmd. The solution is to create a macro __def_gfpflag_names which is used both in show_gfp_flags(), and to define the gfpflag_names[] array in mm/debug.c. On the other hand, mm/debug.c also defines translation tables for page flags and vma flags, and desire was expressed (but not implemented in this series) to use these also from tracepoints. Thus, this patch also renames the events/gfpflags.h file to events/mmflags.h and moves the table definitions there, using the same macro approach as for gfpflags. This allows translating all three kinds of mm-specific flags both in tracepoints and printk. Signed-off-by: Vlastimil Babka Reviewed-by: Michal Hocko Cc: Steven Rostedt Cc: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: Ingo Molnar Cc: Rasmus Villemoes Cc: Joonsoo Kim Cc: Minchan Kim Cc: Sasha Levin Cc: "Kirill A. Shutemov" Cc: Mel Gorman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

tracing: Remove duplicate checks for online CPUs

2016-03-08T16:19:28Z

Some trace events have conditions that check if the current CPU is online or not before recording the tracepoint. That's because certain trace events are in locations that can be called as the CPU is going offline and when RCU no longer monitors it (like kfree and friends). The check was added because trace events require RCU to be active. This is a trace event infrastructure issue and not something that individual trace events should worry about. The tracepoint.h code now has added a check to see if the current CPU is considered online, and it only does the tracepoint if it is. There's no more need for individual trace events to also include this check. It is now redundant. Cc: Shreyas B. Prabhu Signed-off-by: Steven Rostedt

tracing/mm: don't trace mm_page_pcpu_drain on offline cpus

2015-05-29T01:25:18Z

Since tracepoints use RCU for protection, they must not be called on offline cpus. trace_mm_page_pcpu_drain can be called on an offline cpu in this scenario caught by LOCKDEP: =============================== [ INFO: suspicious RCU usage. ] 4.1.0-rc1+ #9 Not tainted ------------------------------- include/trace/events/kmem.h:265 suspicious rcu_dereference_check() usage! other info that might help us debug this: RCU used illegally from offline CPU! rcu_scheduler_active = 1, debug_locks = 1 1 lock held by swapper/5/0: #0: (&(&zone->lock)->rlock){..-...}, at: [] .free_pcppages_bulk+0x70/0x920 stack backtrace: CPU: 5 PID: 0 Comm: swapper/5 Not tainted 4.1.0-rc1+ #9 Call Trace: .dump_stack+0x98/0xd4 (unreliable) .lockdep_rcu_suspicious+0x108/0x170 .free_pcppages_bulk+0x60c/0x920 .free_hot_cold_page+0x208/0x280 .destroy_context+0x90/0xd0 .__mmdrop+0x58/0x160 .idle_task_exit+0xf0/0x100 .pnv_smp_cpu_kill_self+0x58/0x2c0 .cpu_die+0x34/0x50 .arch_cpu_idle_dead+0x20/0x40 .cpu_startup_entry+0x708/0x7a0 .start_secondary+0x36c/0x3a0 start_secondary_prolog+0x10/0x14 Fix this by converting mm_page_pcpu_drain trace point into TRACE_EVENT_CONDITION where condition is cpu_online(smp_processor_id()) Signed-off-by: Shreyas B. Prabhu Reviewed-by: Preeti U Murthy Acked-by: Steven Rostedt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds