- 03 Apr, 2015 1 commit
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Ingo Molnar authored
Merge tag 'perf-core-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo: User visible changes: - Support unnamed union/structure members data collection in 'perf probe'. (Masami Hiramatsu) - Support missing -f to override perf.data file ownership. (Yunlong Song) Infrastructure changes: - No need to lookup thread twice when processing samples in 'perf script'. (Arnaldo Carvalho de Melo) - No need to pass thread twice to the scripting callbacks. (Arnaldo Carvalho de Melo) - No need to pass thread twice to the db-export facility. (Arnaldo Carvalho de Melo) Signed-off-by:
Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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- 02 Apr, 2015 39 commits
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Yunlong Song authored
Enable perf data convert to use perf.data when it is not owned by current user or root. Example: # perf record ls # chown Yunlong.Song:Yunlong.Song perf.data # ls -al perf.data -rw------- 1 Yunlong.Song Yunlong.Song 28260 Apr 2 17:35 perf.data # id uid=0(root) gid=0(root) groups=0(root),64(pkcs11) Before this patch: # perf data convert --to-ctf=./ctf-data/ File perf.data not owned by current user or root (use -f to override) # perf data convert --to-ctf=./ctf-data/ -f Error: unknown switch `f' usage: perf data convert [<options>] -v, --verbose be more verbose -i, --input <file> input file name --to-ctf ... Convert to CTF format After this patch: # perf data convert --to-ctf=./ctf-data/ File perf.data not owned by current user or root (use -f to override) # perf data convert --to-ctf=./ctf-data/ -f # ls ctf-data/ metadata perf_stream_0 As shown above, the -f option really works now. Signed-off-by:Yunlong Song <yunlong.song@huawei.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/1427982439-27388-11-git-send-email-yunlong.song@huawei.comSigned-off-by:
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Yunlong Song authored
Enable perf trace to use perf.data when it is not owned by current user or root. Example: # perf trace record ls # chown Yunlong.Song:Yunlong.Song perf.data # ls -al perf.data -rw------- 1 Yunlong.Song Yunlong.Song 4153101 Apr 2 15:28 perf.data # id uid=0(root) gid=0(root) groups=0(root),64(pkcs11) Before this patch: # perf trace -i perf.data File perf.data not owned by current user or root (use -f to override) # perf trace -i perf.data -f Error: unknown switch `f' usage: perf trace [<options>] [<command>] or: perf trace [<options>] -- <command> [<options>] or: perf trace record [<options>] [<command>] or: perf trace record [<options>] -- <command> [<options>] --event <event> event selector. use 'perf list' to list available events --comm show the thread COMM next to its id --tool_stats show tool stats -e, --expr <expr> list of events to trace -o, --output <file> output file name -i, --input <file> Analyze events in file -p, --pid <pid> trace events on existing process id -t, --tid <tid> trace events on existing thread id --filter-pids <float> ... As shown above, the -f option does not work at all. After this patch: # perf trace -i perf.data File perf.data not owned by current user or root (use -f to override) # perf trace -i perf.data -f 0.056 ( 0.002 ms): ls/47325 brk( ... 0.108 ( 0.018 ms): ls/47325 mmap(len: 4096, prot: READ|WRITE, ... 0.145 ( 0.013 ms): ls/47325 access(filename: 0x7f31259a0eb0, ... 0.172 ( 0.008 ms): ls/47325 open(filename: 0x7fffeb9a0d00, ... 0.180 ( 0.004 ms): ls/47325 stat(filename: 0x7fffeb9a0d00, ... 0.185 ( 0.004 ms): ls/47325 open(filename: 0x7fffeb9a0d00, ... 0.189 ( 0.003 ms): ls/47325 stat(filename: 0x7fffeb9a0d00, ... 0.195 ( 0.004 ms): ls/47325 open(filename: 0x7fffeb9a0d00, ... 0.199 ( 0.002 ms): ls/47325 stat(filename: 0x7fffeb9a0d00, ... 0.205 ( 0.004 ms): ls/47325 open(filename: 0x7fffeb9a0d00, ... 0.211 ( 0.004 ms): ls/47325 stat(filename: 0x7fffeb9a0d00, ... 0.220 ( 0.007 ms): ls/47325 open(filename: 0x7f312599e8ff, ... ... ... As shown above, the -f option really works now. Signed-off-by: -
Yunlong Song authored
Enable perf timechart to use perf.data when it is not owned by current user or root. Example: # perf timechart record ls # chown Yunlong.Song:Yunlong.Song perf.data # ls -al perf.data -rw------- 1 Yunlong.Song Yunlong.Song 5471744 Apr 2 15:15 perf.data # id uid=0(root) gid=0(root) groups=0(root),64(pkcs11) Before this patch: # perf timechart File perf.data not owned by current user or root (use -f to override) # perf timechart -f Error: unknown switch `f' usage: perf timechart [<options>] {record} -i, --input <file> input file name -o, --output <file> output file name -w, --width <n> page width --highlight <duration or task name> highlight tasks. Pass duration in ns or process name. -P, --power-only output power data only -T, --tasks-only output processes data only -p, --process <process> process selector. Pass a pid or process name. --symfs <directory> Look for files with symbols relative to this directory -n, --proc-num <n> min. number of tasks to print -t, --topology sort CPUs according to topology --io-skip-eagain skip EAGAIN errors --io-min-time <time> all IO faster than min-time will visually appear longer --io-merge-dist <time> merge events that are merge-dist us apart As shown above, the -f option does not work at all. After this patch: # perf timechart File perf.data not owned by current user or root (use -f to override) # perf timechart -f Written 0.0 seconds of trace to output.svg. # cat output.svg <?xml version="1.0" standalone="no"?> <!DOCTYPE svg SYSTEM "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd"> <svg width="1000" height="10110" version="1.1" xmlns="http://www.w3.org/2000/svg"> <defs> <style type="text/css"> <![CDATA[ rect { stroke-width: 1; } ... ... As shown above, the -f option really works now. Signed-off-by: -
Yunlong Song authored
Enable perf script to use perf.data when it is not owned by current user or root. Change the short option name of --fields to -F to avoid confusion with --force. Example: # perf record ls # chown Yunlong.Song:Yunlong.Song perf.data # ls -al perf.data -rw------- 1 Yunlong.Song Yunlong.Song 28360 Apr 2 14:53 perf.data # id uid=0(root) gid=0(root) groups=0(root),64(pkcs11) Before this patch: # perf script File perf.data not owned by current user or root (use -f to override) # perf script -f Error: switch `f' requires a value usage: perf script [<options>] or: perf script [<options>] record <script> [<record-options>] <command> or: perf script [<options>] report <script> [script-args] or: perf script [<options>] <script> [<record-options>] <command> or: perf script [<options>] <top-script> [script-args] -f, --fields <str> comma separated output fields prepend with 'type:'. Valid types: hw,sw,trace,raw. Fields: comm,tid,pid,time,cpu,event,trace,ip,sym,dso,addr,symoff,period As shown above, the -f option does not work at all. And -f is already taken up by --fields, which makes --force confused, so change the short option name of --fields to -F like what other perf commands do (e.g. perf report -F) and use -f as the short option name of --force. After this patch: # perf script File perf.data not owned by current user or root (use -f to override) # perf script -f :41298 41298 2590086.564226: 1 cycles: ffffffff8103efc6 native_write_msr_safe ([kernel.kallsyms]) :41298 41298 2590086.564244: 1 cycles: ffffffff8103efc6 native_write_msr_safe ([kernel.kallsyms]) :41298 41298 2590086.564249: 7 cycles: ffffffff8103efc6 native_write_msr_safe ([kernel.kallsyms]) :41298 41298 2590086.564255: 176 cycles: ffffffff8103efc6 native_write_msr_safe ([kernel.kallsyms]) ls 41298 2590086.567346: 4059 cycles: ffffffff8105a592 raise_softirq ([kernel.kallsyms]) ls 41298 2590086.567353: 3717 cycles: ffffffff8105a592 raise_softirq ([kernel.kallsyms]) ls 41298 2590086.567358: 63058 cycles: ffffffff8105a592 raise_softirq ([kernel.kallsyms]) ls 41298 2590086.567448: 1706255 cycles: 406ae0 [unknown] (/usr/bin/ls) As shown above, the -f option really works now. Signed-off-by: -
Yunlong Song authored
Enable perf mem to use perf.data when it is not owned by current user or root. Example: # perf mem -t load record ls # chown Yunlong.Song:Yunlong.Song perf.data # ls -al perf.data -rw------- 1 Yunlong.Song Yunlong.Song 16392 Apr 2 14:34 perf.data # id uid=0(root) gid=0(root) groups=0(root),64(pkcs11) Before this patch: # perf mem -D report File perf.data not owned by current user or root (use -f to override) # perf mem -D -f report Error: unknown switch `f' usage: perf mem [<options>] {record|report} -t, --type <type> memory operations(load,store) Default load,store -D, --dump-raw-samples dump raw samples in ASCII -U, --hide-unresolved Only display entries resolved to a symbol -i, --input <file> input file name -C, --cpu <cpu> list of cpus to profile -x, --field-separator <separator> separator for columns, no spaces will be added between columns '.' is reserved. As shown above, the -f option does not work at all. After this patch: # perf mem -D report File perf.data not owned by current user or root (use -f to override) # perf mem -D -f report # PID, TID, IP, ADDR, LOCAL WEIGHT, DSRC, SYMBOL 39095 39095 0xffffffff81127e40 0x016ffff887f45148338 8 0x68100142 /proc/kcore:perf_event_aux 39095 39095 0xffffffff8100a3fe 0xffff89007f8cb7d0 6 0x68100142 /proc/kcore:native_sched_clock 39095 39095 0xffffffff81309139 0xffff88bf44c9ded8 6 0x68100142 /proc/kcore:acpi_map_lookup 39095 39095 0xffffffff810f8c4c 0xffff89007f8ccd88 6 0x68100142 /proc/kcore:rcu_nmi_exit 39095 39095 0xffffffff81136346 0xffff88fea995dd50 6 0x68100142 /proc/kcore:unlock_page 39095 39095 0xffffffff812a64a2 0xffff88fea995dcc8 6 0x68100142 /proc/kcore:half_md4_transform 39095 39095 0x7f0cf877c7e9 0x25dfb94 6 0x68100142 /lib64/libc-2.19.so:__readdir64 39095 39095 0x7f0cf87575a3 0x7f0cf9163731 6 0x68100142 /lib64/libc-2.19.so:__strcoll_l 39095 39095 0xffffffff8116910e 0xffffea01c1bfbd50 23 0x68100242 /proc/kcore:page_remove_rmap As shown above, the -f option really works now. Signed-off-by: -
Yunlong Song authored
Enable perf lock to use perf.data when it is not owned by current user or root. Example: # perf lock record ls # chown Yunlong.Song:Yunlong.Song perf.data # ls -al perf.data -rw------- 1 Yunlong.Song Yunlong.Song 4880686 Apr 2 14:14 perf.data # id uid=0(root) gid=0(root) groups=0(root),64(pkcs11) Before this patch: # perf lock report File perf.data not owned by current user or root (use -f to override) Initializing perf session failed # perf lock report -f Error: unknown switch `f' usage: perf lock report [<options>] -k, --key <acquired> key for sorting (acquired / contended / avg_wait / wait_total / wait_max / wait_min) As shown above, the -f option does not work at all. After this patch: # perf lock report File perf.data not owned by current user or root (use -f to override) Initializing perf session failed # perf lock report -f Name acquired contended avg wait (ns) total wait (ns) ... &ldata->output_l... 128 0 0 0 ... &ctx->lock 114 0 0 0 ... &p->pi_lock 112 0 0 0 ... &(&pool->lock)->... 112 0 0 0 ... &(&dentry->d_loc... 70 0 0 0 ... &(&newf->file_lo... 62 0 0 0 ... &(&fs->lock)->rl... 43 0 0 0 ... ... As shown above, the -f option really works now. Signed-off-by: -
Yunlong Song authored
Enable perf kvm to use perf.data.guest when it is not owned by current user or root. Example: # perf kvm stat record ls # chown Yunlong.Song:Yunlong.Song perf.data.guest # ls -al perf.data.guest -rw------- 1 Yunlong.Song Yunlong.Song 4128937 Apr 2 11:05 perf.data.guest # id uid=0(root) gid=0(root) groups=0(root),64(pkcs11) Before this patch: # perf kvm stat report File perf.data.guest not owned by current user or root (use -f to override) Initializing perf session failed # perf kvm stat report -f Error: unknown switch `f' usage: perf kvm stat report [<options>] --event <report event> event for reporting: vmexit, mmio (x86 only), ioport (x86 only) --vcpu <n> vcpu id to report -k, --key <sort-key> key for sorting: sample(sort by samples number) time (sort by avg time) -p, --pid <pid> analyze events only for given process id(s) As shown above, the -f option does not work at all. After this patch: # perf kvm stat report File perf.data.guest not owned by current user or root (use -f to override) Initializing perf session failed # perf kvm stat report -f Analyze events for all VMs, all VCPUs: VM-EXIT Samples Samples% Time% Min Time Max Time Avg time Total Samples:0, Total events handled time:0.00us. As shown above, the -f option really works now. Since we have not launched any KVM related process, the result shows 0 sample here. Signed-off-by: -
Yunlong Song authored
Enable perf kmem to use perf.data when it is not owned by current user or root. Example: # perf kmem record ls # chown Yunlong.Song:Yunlong.Song perf.data # ls -al perf.data -rw------- 1 Yunlong.Song Yunlong.Song 5315665 Apr 2 10:54 perf.data # id uid=0(root) gid=0(root) groups=0(root),64(pkcs11) Before this patch: # perf kmem stat File perf.data not owned by current user or root (use -f to override) # perf kmem stat -f Error: unknown switch `f' usage: perf kmem [<options>] {record|stat} -i, --input <file> input file name -v, --verbose be more verbose (show symbol address, etc) --caller show per-callsite statistics --alloc show per-allocation statistics -s, --sort <key[,key2...]> sort by keys: ptr, call_site, bytes, hit, pingpong, frag -l, --line <num> show n lines --raw-ip show raw ip instead of symbol As shown above, the -f option does not work at all. After this patch: # perf kmem stat File perf.data not owned by current user or root (use -f to override) # perf kmem stat -f SUMMARY ======= Total bytes requested: 437599 Total bytes allocated: 615472 Total bytes wasted on internal fragmentation: 177873 Internal fragmentation: 28.900259% Cross CPU allocations: 6/1192 As shown above, the -f option really works now. Signed-off-by: -
Yunlong Song authored
Enable perf inject to use perf.data when it is not owned by current user or root. Example: # perf record ls # chown Yunlong.Song:Yunlong.Song perf.data # ls -al perf.data -rw------- 1 Yunlong.Song Yunlong.Song 28260 Apr 2 10:37 perf.data # id uid=0(root) gid=0(root) groups=0(root),64(pkcs11) Before this patch: # perf inject -v -b -i perf.data -o perf.data.new File perf.data not owned by current user or root (use -f to override) # perf inject -v -b -i perf.data -o perf.data.new -f Error: unknown switch `f' usage: perf inject [<options>] -b, --build-ids Inject build-ids into the output stream -i, --input <file> input file name -o, --output <file> output file name -s, --sched-stat Merge sched-stat and sched-switch for getting events where and how long tasks slept -v, --verbose be more verbose (show build ids, etc) --kallsyms <file> kallsyms pathname As shown above, the -f option does not work at all. After this patch: # perf inject -v -b -i perf.data -o perf.data.new File perf.data not owned by current user or root (use -f to override) # perf inject -v -b -i perf.data -o perf.data.new -f build id event received for [kernel.kallsyms]: f6dcb66d8b98f1c0d9eb87bf043444b69f91d30c symsrc__init: cannot get elf header. Looking at the vmlinux_path (7 entries long) Using /proc/kcore for kernel object code Using /proc/kallsyms for symbols As shown above, the -f option really works now. Signed-off-by: -
Yunlong Song authored
Enable perf evlist to use perf.data when it is not owned by current user or root. Example: # perf record ls # chown Yunlong.Song:Yunlong.Song perf.data # ls -al perf.data -rw------- 1 Yunlong.Song Yunlong.Song 28260 Apr 2 10:18 perf.data # id uid=0(root) gid=0(root) groups=0(root),64(pkcs11) Before this patch: # perf evlist File perf.data not owned by current user or root (use -f to override) # perf evlist -f Error: unknown switch `f' usage: perf evlist [<options>] -i, --input <file> Input file name -F, --freq Show the sample frequency -v, --verbose Show all event attr details -g, --group Show event group information As shown above, the -f option does not work at all. After this patch: # perf evlist File perf.data not owned by current user or root (use -f to override) # perf evlist -f cycles As shown above, the -f option really works now. Signed-off-by: -
Masami Hiramatsu authored
Fix 'perf probe' to track down unnamed union/structure members. perf probe did not track down the tree of unnamed union/structure members, since it just failed to find given "name" in a parent structure/union. To solve this issue, I've introduced 2 changes. - Fix die_find_member() to track down the type-DIE if it is unnamed, and if it contains the specified member, returns the unnamed member. (note that we don't return found member, since unnamed member has the offset in the parent structure) - Fix convert_variable_fields() to track down the unnamed union/ structure (one-by-one). With this patch, perf probe can access unnamed fields: ----- #./perf probe -nfx ./perf lock__delete ops 'locked_ops=ops->locked.ops' Added new event: probe_perf:lock__delete (on lock__delete in /home/mhiramat/ksrc/linux-3/tools/perf/perf with ops locked_ops=ops->locked.ops) You can now use it in all perf tools, such as: perf record -e probe_perf:lock__delete -aR sleep 1 ----- Reported-by:Arnaldo Carvalho de Melo <acme@kernel.org> Report-Link: https://lkml.org/lkml/2015/3/5/431Signed-off-by:
Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Tested-by:
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Arnaldo Carvalho de Melo authored
As it comes from address_location->thread, that is already stored as export_sample->al, where the thread can be obtained. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: David Ahern <dsahern@gmail.com> Cc: Don Zickus <dzickus@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/r/20150402141542.GA9630@kernel.org Link: http://lkml.kernel.org/n/tip-bzotbl4epoztw0jd6sm2stpf@git.kernel.orgSigned-off-by:
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Arnaldo Carvalho de Melo authored
As it is available via another parameter, address_location->thread. Acked-by:
Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: David Ahern <dsahern@gmail.com> Cc: Don Zickus <dzickus@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> Link: lkml.kernel.org/r/551D08F8.3040706@intel.com Link: http://lkml.kernel.org/n/tip-6dbn0tcm9hyv92g7h3zj2dbt@git.kernel.orgSigned-off-by:
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Arnaldo Carvalho de Melo authored
It is already in the addr_location, so remove the redundant 'thread' parameter from the callback signatures. Acked-by:
Jiri Olsa <jolsa@redhat.com> Acked-by:
Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: David Ahern <dsahern@gmail.com> Cc: Don Zickus <dzickus@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/r/1427906210-10519-3-git-send-email-acme@kernel.orgSigned-off-by:
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Arnaldo Carvalho de Melo authored
We get the thread when we call perf_event__preprocess_sample(), no need to do it before that. Acked-by:
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Ingo Molnar authored
On a 32-bit build I got: arch/x86/kernel/cpu/perf_event_intel_pt.c:413:5: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast] arch/x86/kernel/cpu/perf_event_intel_bts.c:162:24: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast] Fix it. The code should probably be (re-)tested on 32-bit systems to make sure all is fine. Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kaixu Xia <kaixu.xia@linaro.org> Cc: linux-kernel@vger.kernel.org Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Robert Richter <rric@kernel.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: acme@infradead.org Cc: adrian.hunter@intel.com Cc: kan.liang@intel.com Cc: markus.t.metzger@intel.com Cc: mathieu.poirier@linaro.org Signed-off-by: -
Andi Kleen authored
perf with LBRs on has a tendency to rewrite the DEBUGCTL MSR with the same value. Add a little optimization to skip the unnecessary write. Signed-off-by:
Andi Kleen <ak@linux.intel.com> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: eranian@google.com Link: http://lkml.kernel.org/r/1426871484-21285-2-git-send-email-andi@firstfloor.orgSigned-off-by:
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Andi Kleen authored
The perf PMI currently does unnecessary MSR accesses when LBRs are enabled. We use LBR freezing, or when in callstack mode force the LBRs to only filter on ring 3. So there is no need to disable the LBRs explicitely in the PMI handler. Also we always unnecessarily rewrite LBR_SELECT in the LBR handler, even though it can never change. 5) | /* write_msr: MSR_LBR_SELECT(1c8), value 0 */ 5) | /* read_msr: MSR_IA32_DEBUGCTLMSR(1d9), value 1801 */ 5) | /* write_msr: MSR_IA32_DEBUGCTLMSR(1d9), value 1801 */ 5) | /* write_msr: MSR_CORE_PERF_GLOBAL_CTRL(38f), value 70000000f */ 5) | /* write_msr: MSR_CORE_PERF_GLOBAL_CTRL(38f), value 0 */ 5) | /* write_msr: MSR_LBR_SELECT(1c8), value 0 */ 5) | /* read_msr: MSR_IA32_DEBUGCTLMSR(1d9), value 1801 */ 5) | /* write_msr: MSR_IA32_DEBUGCTLMSR(1d9), value 1801 */ This patch: - Avoids disabling already frozen LBRs unnecessarily in the PMI - Avoids changing LBR_SELECT in the PMI Signed-off-by:
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Andi Kleen authored
Technically PEBS_ENABLED is only guaranteed to exist when we detected PEBS. So add a check for this to the PMU dump function. I don't think it can happen on a real CPU, but could in a VM. Signed-off-by:
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Andi Kleen authored
LBRs and LBR freezing are controlled through the DEBUGCTL MSR. So dump the state of DEBUGCTL too when dumping the PMU state. Signed-off-by:
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Andi Kleen authored
The PMU reset code didn't quite keep up with newer PMU features. Improve it a bit to really reset a modern PMU: - Clear all overflow status - Clear LBRs and freezing state - Disable fixed counters too Signed-off-by:
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Stephane Eranian authored
This patch disables the PMU HT bug when Hyperthreading (HT) is disabled. We cannot do this test immediately when perf_events is initialized. We need to wait until the topology information is setup properly. As such, we register a later initcall, check the topology and potentially disable the workaround. To do this, we need to ensure there is no user of the PMU. At this point of the boot, the only user is the NMI watchdog, thus we disable it during the switch and re-enable it right after. Having the workaround disabled when it is not needed provides some benefits by limiting the overhead is time and space. The workaround still ensures correct scheduling of the corrupting memory events (0xd0, 0xd1, 0xd2) when HT is off. Those events can only be measured on counters 0-3. Something else the current kernel did not handle correctly. Signed-off-by:
Stephane Eranian <eranian@google.com> Signed-off-by:
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Stephane Eranian authored
This patch adds two new functions to enable/disable the watchdog across all CPUs. This will be used by the HT PMU bug workaround code to disable/enable the NMI watchdog across quirk enablement. Signed-off-by:
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Stephane Eranian authored
perf/x86/intel: Limit to half counters when the HT workaround is enabled, to avoid exclusive mode starvation This patch limits the number of counters available to each CPU when the HT bug workaround is enabled. This is necessary to avoid situation of counter starvation. Such can arise from configuration where one HT thread, HT0, is using all 4 counters with corrupting events which require exclusion the the sibling HT, HT1. In such case, HT1 would not be able to schedule any event until HT0 is done. To mitigate this problem, this patch artificially limits the number of counters to 2. That way, we can gurantee that at least 2 counters are not in exclusive mode and therefore allow the sibling thread to schedule events of the same type (system vs. per-thread). The 2 counters are not determined in advance. We simply set the limit to two events per HT. This helps mitigate starvation in case of events with specific counter constraints such a PREC_DIST. Note that this does not elimintate the starvation is all cases. But it is better than not having it. (Solution suggested by Peter Zjilstra.) Signed-off-by:
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Stephane Eranian authored
With dynamic constraint, we need to restart from the static constraints each time the intel_get_event_constraints() is called. Signed-off-by:
Maria Dimakopoulou <maria.n.dimakopoulou@gmail.com> Cc: bp@alien8.de Cc: jolsa@redhat.com Cc: kan.liang@intel.com Link: http://lkml.kernel.org/r/1416251225-17721-10-git-send-email-eranian@google.comSigned-off-by:
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Maria Dimakopoulou authored
This patch modifies the PEBS constraint tables for SNB/IVB/HSW such that corrupting events supporting PEBS activate the HT workaround. Signed-off-by:
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Maria Dimakopoulou authored
This patches activates the HT bug workaround for the SNB/IVB/HSW processors. This covers non-PEBS mode. Activation is done thru the constraint tables. Both client and server processors needs this workaround. Signed-off-by:
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Maria Dimakopoulou authored
This patch implements a software workaround for a HW erratum on Intel SandyBridge, IvyBridge and Haswell processors with Hyperthreading enabled. The errata are documented for each processor in their respective specification update documents: - SandyBridge: BJ122 - IvyBridge: BV98 - Haswell: HSD29 The bug causes silent counter corruption across hyperthreads only when measuring certain memory events (0xd0, 0xd1, 0xd2, 0xd3). Counters measuring those events may leak counts to the sibling counter. For instance, counter 0, thread 0 measuring event 0xd0, may leak to counter 0, thread 1, regardless of the event measured there. The size of the leak is not predictible. It all depends on the workload and the state of each sibling hyper-thread. The corrupting events do undercount as a consequence of the leak. The leak is compensated automatically only when the sibling counter measures the exact same corrupting event AND the workload is on the two threads is the same. Given, there is no way to guarantee this, a work-around is necessary. Furthermore, there is a serious problem if the leaked count is added to a low-occurrence event. In that case the corruption on the low occurrence event can be very large, e.g., orders of magnitude. There is no HW or FW workaround for this problem. The bug is very easy to reproduce on a loaded system. Here is an example on a Haswell client, where CPU0, CPU4 are siblings. We load the CPUs with a simple triad app streaming large floating-point vector. We use 0x81d0 corrupting event (MEM_UOPS_RETIRED:ALL_LOADS) and 0x20cc (ROB_MISC_EVENTS:LBR_INSERTS). Given we are not using the LBR, the 0x20cc event should be zero. $ taskset -c 0 triad & $ taskset -c 4 triad & $ perf stat -a -C 0 -e r81d0 sleep 100 & $ perf stat -a -C 4 -r20cc sleep 10 Performance counter stats for 'system wide': 139 277 291 r20cc 10,000969126 seconds time elapsed In this example, 0x81d0 and r20cc ar eusing sinling counters on CPU0 and CPU4. 0x81d0 leaks into 0x20cc and corrupts it from 0 to 139 millions occurrences. This patch provides a software workaround to this problem by modifying the way events are scheduled onto counters by the kernel. The patch forces cross-thread mutual exclusion between counters in case a corrupting event is measured by one of the hyper-threads. If thread 0, counter 0 is measuring event 0xd0, then nothing can be measured on counter 0, thread 1. If no corrupting event is measured on any hyper-thread, event scheduling proceeds as before. The same example run with the workaround enabled, yield the correct answer: $ taskset -c 0 triad & $ taskset -c 4 triad & $ perf stat -a -C 0 -e r81d0 sleep 100 & $ perf stat -a -C 4 -r20cc sleep 10 Performance counter stats for 'system wide': 0 r20cc 10,000969126 seconds time elapsed The patch does provide correctness for all non-corrupting events. It does not "repatriate" the leaked counts back to the leaking counter. This is planned for a second patch series. This patch series makes this repatriation more easy by guaranteeing the sibling counter is not measuring any useful event. The patch introduces dynamic constraints for events. That means that events which did not have constraints, i.e., could be measured on any counters, may now be constrained to a subset of the counters depending on what is going on the sibling thread. The algorithm is similar to a cache coherency protocol. We call it XSU in reference to Exclusive, Shared, Unused, the 3 possible states of a PMU counter. As a consequence of the workaround, users may see an increased amount of event multiplexing, even in situtations where there are fewer events than counters measured on a CPU. Patch has been tested on all three impacted processors. Note that when HT is off, there is no corruption. However, the workaround is still enabled, yet not costing too much. Adding a dynamic detection of HT on turned out to be complex are requiring too much to code to be justified. This patch addresses the issue when PEBS is not used. A subsequent patch fixes the problem when PEBS is used. Signed-off-by: -
Maria Dimakopoulou authored
This patch adds a new shared_regs style structure to the per-cpu x86 state (cpuc). It is used to coordinate access between counters which must be used with exclusion across HyperThreads on Intel processors. This new struct is not needed on each PMU, thus is is allocated on demand. Signed-off-by:
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Stephane Eranian authored
This patch adds an index parameter to the get_event_constraint() x86_pmu callback. It is expected to represent the index of the event in the cpuc->event_list[] array. When the callback is used for fake_cpuc (evnet validation), then the index must be -1. The motivation for passing the index is to use it to index into another cpuc array. Signed-off-by:
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Maria Dimakopoulou authored
This patch adds 3 new PMU model specific callbacks during the event scheduling done by x86_schedule_events(). ->start_scheduling(): invoked when entering the schedule routine. ->stop_scheduling(): invoked at the end of the schedule routine ->commit_scheduling(): invoked for each committed event To be used optionally by model-specific code. Signed-off-by:
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Stephane Eranian authored
Make the cpuc->kfree_on_online a vector to accommodate more than one entry and add the second entry to be used by a later patch. Signed-off-by:
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Stephane Eranian authored
Because it will be used for more than just tracking the presence of extra registers. Signed-off-by:
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Ingo Molnar authored
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Alexander Shishkin authored
Add support for Branch Trace Store (BTS) via kernel perf event infrastructure. The difference with the existing implementation of BTS support is that this one is a separate PMU that exports events' trace buffers to userspace by means of AUX area of the perf buffer, which is zero-copy mapped into userspace. The immediate benefit is that the buffer size can be much bigger, resulting in fewer interrupts and no kernel side copying is involved and little to no trace data loss. Also, kernel code can be traced with this driver. The old way of collecting BTS traces still works. Signed-off-by:
Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by:
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Alexander Shishkin authored
Add support for Intel Processor Trace (PT) to kernel's perf events. PT is an extension of Intel Architecture that collects information about software execuction such as control flow, execution modes and timings and formats it into highly compressed binary packets. Even being compressed, these packets are generated at hundreds of megabytes per second per core, which makes it impractical to decode them on the fly in the kernel. This driver exports trace data by through AUX space in the perf ring buffer, which is zero-copy mapped into userspace for faster data retrieval. Signed-off-by:
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Alexander Shishkin authored
Intel PT cannot be used at the same time as LBR or BTS and will cause a general protection fault if they are used together. In order to avoid fixing up GPs in the fast path, instead we disallow creating LBR/BTS events when PT events are present and vice versa. Signed-off-by:
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Alexander Shishkin authored
Intel Processor Trace is an architecture extension that allows for program flow tracing. Signed-off-by:
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Alexander Shishkin authored
For counters that generate AUX data that is bound to the context of a running task, such as instruction tracing, the decoder needs to know exactly which task is running when the event is first scheduled in, before the first sched_switch. The decoder's need to know this stems from the fact that instruction flow trace decoding will almost always require program's object code in order to reconstruct said flow and for that we need at least its pid/tid in the perf stream. To single out such instruction tracing pmus, this patch introduces ITRACE PMU capability. The reason this is not part of RECORD_AUX record is that not all pmus capable of generating AUX data need this, and the opposite is *probably* also true. While sched_switch covers for most cases, there are two problems with it: the consumer will need to process events out of order (that is, having found RECORD_AUX, it will have to skip forward to the nearest sched_switch to figure out which task it was, then go back to the actual trace to decode it) and it completely misses the case when the tracing is enabled and disabled before sched_switch, for example, via PERF_EVENT_IOC_DISABLE. Signed-off-by:
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