- 07 Aug, 2013 25 commits
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Adrian Hunter authored
Using the information in mmap events, perf tools can read object code associated with sampled addresses. A test is added that compares bytes read by perf with the same bytes read using objdump. Signed-off-by:
Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/r/1375875537-4509-2-git-send-email-adrian.hunter@intel.comSigned-off-by:
Arnaldo Carvalho de Melo <acme@redhat.com>
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Adrian Hunter authored
When removing duplicate symbols, prefer to remove syscall aliases starting with SyS or compat_SyS. A side-effect of that is that it results in slightly improved results for the "vmlinux symtab matches kallsyms" test. Signed-off-by:
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Andi Kleen authored
When interval mode is outputting to a pipe, each measurement should be flushed individually, so that the reader sees it timely. With a terminal each line is automatically flushed by stdio, but that is disabled with non terminal output. Simply fflush output after each time interval Signed-off-by:
Andi Kleen <ak@linux.intel.com> Reviewed-by:
Jiri Olsa <jolsa@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/r/1375490473-1503-5-git-send-email-andi@firstfloor.orgSigned-off-by:
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Andi Kleen authored
When measuring workloads the startup phase -- doing page faults, dynamic linking, opening files -- is often very different from the rest of the workload. Especially with smaller kernels and using counter multiplexing this can give significant measurement errors. Multiplexing assumes that the workload is mostly the same over longer periods. But at startup there is typically some spike of activity which is relatively short. If many groups are multiplexing the one group seeing the spike, and which is then scaled up over the time to run all groups, may see a significant error. Also in general it's often not useful to measure the startup, because it is so different from the rest. One way around this is to use interval mode and discard the first sample, but this can be awkward because interval mode doesn't support intervals of less than 100ms, and also a useful interval is not necessarily the same as a useful startup delay. This patch adds a new --initial-delay / -D option to skip measuring for the startup phase. The time can be specified in ms Here's a simple example: perf stat -e page-faults bash -c 'for i in $(seq 100000) ; do true ; done' ... 3,721 page-faults ... If we just wait 20 ms the number of page faults is 1/3 less: perf stat -D 20 -e page-faults bash -c 'for i in $(seq 100000) ; do true ; done' ... 2,823 page-faults ... So we filtered out most of the startup noise from bash. Signed-off-by: -
Andi Kleen authored
Add support for enabling already set up counters by using an ioctl. I share some code with the filter setup. Signed-off-by:
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Andi Kleen authored
Minor cleanup. The dummy execve to pre-resolve the PLT is obsolete since "enable_on_execve" was added. The counters are only running after the execve anyways. So just remove it. Signed-off-by:
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David Ahern authored
Needed by kvm live command. Make record_args a local while we are messing with the args. Signed-off-by:
David Ahern <dsahern@gmail.com> Reviewed-by:
Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Runzhen Wang <runzhen@linux.vnet.ibm.com> Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/1375473947-64285-5-git-send-email-dsahern@gmail.comSigned-off-by:
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David Ahern authored
Allows kvm live mode to reuse the event processing and ordered samples processing used by the perf-report path. v2: removed flush_sample_queue as noticed by Jiri Signed-off-by:
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David Ahern authored
Need an initialization function to set min to -1 to differentiate from an actual min of 0. Signed-off-by:
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David Ahern authored
For use with kvm-live mode. Signed-off-by:
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Namhyung Kim authored
The parse_nsec_time() function is for parsing a string of time into 64-bit nsec value. It's a preparation of time filtering in some of perf commands. Signed-off-by:
Namhyung Kim <namhyung@kernel.org> Tested-by:
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Arnaldo Carvalho de Melo authored
Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thiago Peixoto <thiagolcpeixoto@gmail.com> Link: http://lkml.kernel.org/n/tip-jurgz6myq125o1ql6lldh6f7@git.kernel.orgSigned-off-by:
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Arnaldo Carvalho de Melo authored
It is an errno, so print an error string. Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/n/tip-zt68gijvvoe8gd7kmclo43si@git.kernel.orgSigned-off-by:
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David Ahern authored
On Fedora 18, with gcc 4.6.4 compile fails with: arch/x86/util/tsc.c: In function ‘perf_time_to_tsc’: arch/x86/util/tsc.c:13:6: error: declaration of ‘time’ shadows a global declaration [-Werror=shadow] cc1: all warnings being treated as errors make: *** [/tmp/junk/arch/x86/util/tsc.o] Error 1 make: *** Waiting for unfinished jobs.... Fix by renaming the local variable. Signed-off-by:
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David Ahern authored
Symbol offset is one of the fields that can be requested in perf-script. Currently you do not get that data when requested. e.g., perf script -f comm,tid,pid,time,cpu,sym,symoff,ip ... gcc 6201/6201 [006] 762250.617897: ffffffff81090d95 update_curr ffffffff810911b8 dequeue_entity ffffffff81091825 dequeue_task_fair ffffffff81087163 dequeue_task ffffffff81087c03 deactivate_task ... With this patch you get the offset: ... gcc 6201/6201 [006] 762250.617897: ffffffff81090d95 update_curr+0x1c5 ffffffff810911b8 dequeue_entity+0x28 ffffffff81091825 dequeue_task_fair+0x45 ffffffff81087163 dequeue_task+0x93 ffffffff81087c03 deactivate_task+0x23 ... Signed-off-by: -
Jiri Olsa authored
Adding 2 more tests to the automated parse events suite for following event config: '{cycles,cache-misses,branch-misses}:S' '{instructions,branch-misses}:Su' Signed-off-by: -
Jiri Olsa authored
Adding test to validate perf_event_attr data for command: 'record -e '{cycles,cache-misses}:S' Signed-off-by: -
Jiri Olsa authored
Adding 'S' event/group modifier to specify that the event value/s are read by PERF_SAMPLE_READ sample type processing, instead of the period value offered by lower layers. There's additional behaviour change for 'S' modifier being specified on event group: Currently all the events within a group makes samples. If user now specifies 'S' within group modifier, only the leader will trigger samples. The rest of events in the group will have sampling disabled. And same as for single events, values of all events within the group (including leader) are read by PERF_SAMPLE_READ sample type processing. Following example will create event group with cycles and cache-misses events, setting the cycles as group leader and the only event to actually sample. Both cycles and cache-misses event period values are read by PERF_SAMPLE_READ sample type processing with PERF_FORMAT_GROUP read format. Example: $ perf record -e '{cycles,cache-misses}:S' ls ... $ perf report --group --show-total-period --stdio ... # Samples: 36 of event 'anon group { cycles, cache-misses }' # Event count (approx.): 12585593 # # Overhead Period Command Shared Object Symbol # .............. .............. ....... ................. .......................... # 19.92% 1.20% 2505936 31 ls [kernel.kallsyms] [k] mark_held_locks 13.74% 0.47% 1729327 12 ls [kernel.kallsyms] [k] sched_clock_local 13.64% 23.72% 1716147 612 ls ld-2.14.90.so [.] check_match.10805 13.12% 23.22% 1650778 599 ls libc-2.14.90.so [.] _nl_intern_locale_data 11.24% 29.19% 1414554 753 ls [kernel.kallsyms] [k] sched_clock_cpu 8.50% 0.35% 1070150 9 ls [kernel.kallsyms] [k] check_chain_key ... Signed-off-by: -
Jiri Olsa authored
For sample with sample type PERF_SAMPLE_READ the period value is stored in the 'struct sample_read'. Moreover if the read format has PERF_FORMAT_GROUP, the 'struct sample_read' contains period values for all events in the group (for which the sample's event is a leader). We deliver separated samples for all the values contained within the 'struct sample_read'. Signed-off-by:
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Jiri Olsa authored
This will be helpful for PERF_FORMAT_GROUP samples where we need to store ID related period value for each event. Signed-off-by:
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Jiri Olsa authored
We need to fail the event ID retrieval in case both following conditions are true: - we are on kernel with no PERF_EVENT_IOC_ID support - PERF_FORMAT_GROUP read format is set The PERF_FORMAT_GROUP read format bit is the killer for retrieving event ID out of the read syscall, because we have no guarantee of the event placement within leader kernel sibling list. Signed-off-by:
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Jiri Olsa authored
Adding support to parse out the PERF_SAMPLE_READ sample bits. The code contains both single and group format specification. This code parse out and prepare PERF_SAMPLE_READ data into the perf_sample struct. It will be used for group leader sampling feature comming in shortly. Signed-off-by:
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Jiri Olsa authored
Changing the way we retrieve the event ID. Instead of parsing out the ID out of the read data, using the PERF_EVENT_IOC_ID ioctl. Keeping the old way in place to support kernels without PERF_EVENT_IOC_ID ioctl support. This will be useful for retrieving the event ID for events with PERF_FORMAT_GROUP read format set, where it's impossible to get correct event id out of the read call data. Signed-off-by:
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Jiri Olsa authored
It's possible some of the counters in the group could be disabled when sampling member of the event group is reading the rest via PERF_SAMPLE_READ sample type processing. Disabled counters could then produce wrong numbers. Fixing that by reading only enabled counters for PERF_SAMPLE_READ sample type processing. Signed-off-by:
Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/n/tip-wwkjb0bbcuslnz0klrmqi26r@git.kernel.orgSigned-off-by:
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Jiri Olsa authored
The only way to get the event ID is by reading the event fd, followed by parsing the ID value out of the returned data. While this is ok for current read format used by perf tool, it is not ok when we use PERF_FORMAT_GROUP format. With this format the data are returned for the whole group and there's no way to find out what ID belongs to our fd (if we are not group leader event). Adding a simple ioctl that returns event primary ID for given fd. Signed-off-by:
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- 30 Jul, 2013 8 commits
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Frederic Weisbecker authored
A perf event can be used without forcing the tick to stay alive if it doesn't use a frequency but a sample period and if it doesn't throttle (raise storm of events). Since the lockup detector neither use a perf event frequency nor should ever throttle due to its high period, it can now run concurrently with the full dynticks feature. So remove the hack that disabled the watchdog. Signed-off-by:
Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Stephane Eranian <eranian@google.com> Cc: Don Zickus <dzickus@redhat.com> Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Cc: Anish Singh <anish198519851985@gmail.com> Signed-off-by:
Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1374539466-4799-9-git-send-email-fweisbec@gmail.comSigned-off-by:
Ingo Molnar <mingo@kernel.org>
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Frederic Weisbecker authored
Currently the full dynticks subsystem keep the tick alive as long as there are perf events running. This prevents the tick from being stopped as long as features such that the lockup detectors are running. As a temporary fix, the lockup detector is disabled by default when full dynticks is built but this is not a long term viable solution. To fix this, only keep the tick alive when an event configured with a frequency rather than a period is running on the CPU, or when an event throttles on the CPU. These are the only purposes of the perf tick, especially now that the rotation of flexible events is handled from a seperate hrtimer. The tick can be shutdown the rest of the time. Original-patch-by:
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Frederic Weisbecker authored
This is going to be used by the full dynticks subsystem as a finer-grained information to know when to keep and when to stop the tick. Original-patch-by:
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Frederic Weisbecker authored
When an event is migrated, move the event per-cpu accounting accordingly so that branch stack and cgroup events work correctly on the new CPU. Original-patch-by:
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Frederic Weisbecker authored
This way we can use the per-cpu handling seperately. This is going to be used by to fix the event migration code accounting. Original-patch-by:
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Frederic Weisbecker authored
Gather all the event accounting code to a single place, once all the prerequisites are completed. This simplifies the refcounting. Original-patch-by:
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Frederic Weisbecker authored
In case of allocation failure, get_callchain_buffer() keeps the refcount incremented for the current event. As a result, when get_callchain_buffers() returns an error, we must cleanup what it did by cancelling its last refcount with a call to put_callchain_buffers(). This is a hack in order to be able to call free_event() after that failure. The original purpose of that was to simplify the failure path. But this error handling is actually counter intuitive, ugly and not very easy to follow because one expect to see the resources used to perform a service to be cleaned by the callee if case of failure, not by the caller. So lets clean this up by cancelling the refcount from get_callchain_buffer() in case of failure. And correctly free the event accordingly in perf_event_alloc(). Signed-off-by:
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Frederic Weisbecker authored
On callchain buffers allocation failure, free_event() is called and all the accounting performed in perf_event_alloc() for that event is cancelled. But if the event has branch stack sampling, it is unaccounted as well from the branch stack sampling events refcounts. This is a bug because this accounting is performed after the callchain buffer allocation. As a result, the branch stack sampling events refcount can become negative. To fix this, move the branch stack event accounting before the callchain buffer allocation. Reported-by:
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- 23 Jul, 2013 7 commits
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Peter Zijlstra authored
Smart wake-affine is using node-size as the factor currently, but the overhead of the mask operation is high. Thus, this patch introduce the 'sd_llc_size' percpu variable, which will record the highest cache-share domain size, and make it to be the new factor, in order to reduce the overhead and make it more reasonable. Tested-by:
Davidlohr Bueso <davidlohr.bueso@hp.com> Tested-by:
Michael Wang <wangyun@linux.vnet.ibm.com> Signed-off-by:
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Michael Wang authored
The wake-affine scheduler feature is currently always trying to pull the wakee close to the waker. In theory this should be beneficial if the waker's CPU caches hot data for the wakee, and it's also beneficial in the extreme ping-pong high context switch rate case. Testing shows it can benefit hackbench up to 15%. However, the feature is somewhat blind, from which some workloads such as pgbench suffer. It's also time-consuming algorithmically. Testing shows it can damage pgbench up to 50% - far more than the benefit it brings in the best case. So wake-affine should be smarter and it should realize when to stop its thankless effort at trying to find a suitable CPU to wake on. This patch introduces 'wakee_flips', which will be increased each time the task flips (switches) its wakee target. So a high 'wakee_flips' value means the task has more than one wakee, and the bigger the number, the higher the wakeup frequency. Now when making the decision on whether to pull or not, pay attention to the wakee with a high 'wakee_flips', pulling such a task may benefit the wakee. Also imply that the waker will face cruel competition later, it could be very cruel or very fast depends on the story behind 'wakee_flips', waker therefore suffers. Furthermore, if waker also has a high 'wakee_flips', that implies that multiple tasks rely on it, then waker's higher latency will damage all of them, so pulling wakee seems to be a bad deal. Thus, when 'waker->wakee_flips / wakee->wakee_flips' becomes higher and higher, the cost of pulling seems to be worse and worse. The patch therefore helps the wake-affine feature to stop its pulling work when: wakee->wakee_flips > factor && waker->wakee_flips > (factor * wakee->wakee_flips) The 'factor' here is the number of CPUs in the current CPU's NUMA node, so a bigger node will lead to more pulling since the trial becomes more severe. After applying the patch, pgbench shows up to 40% improvements and no regressions. Tested with 12 cpu x86 server and tip 3.10.0-rc7. The percentages in the final column highlight the areas with the biggest wins, all other areas improved as well: pgbench base smart | db_size | clients | tps | | tps | +---------+---------+-------+ +-------+ | 22 MB | 1 | 10598 | | 10796 | | 22 MB | 2 | 21257 | | 21336 | | 22 MB | 4 | 41386 | | 41622 | | 22 MB | 8 | 51253 | | 57932 | | 22 MB | 12 | 48570 | | 54000 | | 22 MB | 16 | 46748 | | 55982 | +19.75% | 22 MB | 24 | 44346 | | 55847 | +25.93% | 22 MB | 32 | 43460 | | 54614 | +25.66% | 7484 MB | 1 | 8951 | | 9193 | | 7484 MB | 2 | 19233 | | 19240 | | 7484 MB | 4 | 37239 | | 37302 | | 7484 MB | 8 | 46087 | | 50018 | | 7484 MB | 12 | 42054 | | 48763 | | 7484 MB | 16 | 40765 | | 51633 | +26.66% | 7484 MB | 24 | 37651 | | 52377 | +39.11% | 7484 MB | 32 | 37056 | | 51108 | +37.92% | 15 GB | 1 | 8845 | | 9104 | | 15 GB | 2 | 19094 | | 19162 | | 15 GB | 4 | 36979 | | 36983 | | 15 GB | 8 | 46087 | | 49977 | | 15 GB | 12 | 41901 | | 48591 | | 15 GB | 16 | 40147 | | 50651 | +26.16% | 15 GB | 24 | 37250 | | 52365 | +40.58% | 15 GB | 32 | 36470 | | 50015 | +37.14% Signed-off-by:
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Vladimir Davydov authored
The bad thing about update_h_load(), which computes hierarchical load factor for task groups, is that it is called for each task group in the system before every load balancer run, and since rebalance can be triggered very often, this function can eat really a lot of cpu time if there are many cpu cgroups in the system. Although the situation was improved significantly by commit a35b6466 ('sched, cgroup: Reduce rq->lock hold times for large cgroup hierarchies'), the problem still can arise under some kinds of loads, e.g. when cpus are switching from idle to busy and back very frequently. For instance, when I start 1000 of processes that wake up every millisecond on my 8 cpus host, 'top' and 'perf top' show: Cpu(s): 17.8%us, 24.3%sy, 0.0%ni, 57.9%id, 0.0%wa, 0.0%hi, 0.0%si Events: 243K cycles 7.57% [kernel] [k] __schedule 7.08% [kernel] [k] timerqueue_add 6.13% libc-2.12.so [.] usleep Then if I create 10000 *idle* cpu cgroups (no processes in them), cpu usage increases significantly although the 'wakers' are still executing in the root cpu cgroup: Cpu(s): 19.1%us, 48.7%sy, 0.0%ni, 31.6%id, 0.0%wa, 0.0%hi, 0.7%si Events: 230K cycles 24.56% [kernel] [k] tg_load_down 5.76% [kernel] [k] __schedule This happens because this particular kind of load triggers 'new idle' rebalance very frequently, which requires calling update_h_load(), which, in turn, calls tg_load_down() for every *idle* cpu cgroup even though it is absolutely useless, because idle cpu cgroups have no tasks to pull. This patch tries to improve the situation by making h_load calculation proceed only when h_load is really necessary. To achieve this, it substitutes update_h_load() with update_cfs_rq_h_load(), which computes h_load only for a given cfs_rq and all its ascendants, and makes the load balancer call this function whenever it considers if a task should be pulled, i.e. it moves h_load calculations directly to task_h_load(). For h_load of the same cfs_rq not to be updated multiple times (in case several tasks in the same cgroup are considered during the same balance run), the patch keeps the time of the last h_load update for each cfs_rq and breaks calculation when it finds h_load to be uptodate. The benefit of it is that h_load is computed only for those cfs_rq's, which really need it, in particular all idle task groups are skipped. Although this, in fact, moves h_load calculation under rq lock, it should not affect latency much, because the amount of work done under rq lock while trying to pull tasks is limited by sched_nr_migrate. After the patch applied with the setup described above (1000 wakers in the root cgroup and 10000 idle cgroups), I get: Cpu(s): 16.9%us, 24.8%sy, 0.0%ni, 58.4%id, 0.0%wa, 0.0%hi, 0.0%si Events: 242K cycles 7.57% [kernel] [k] __schedule 6.70% [kernel] [k] timerqueue_add 5.93% libc-2.12.so [.] usleep Signed-off-by:
Vladimir Davydov <vdavydov@parallels.com> Signed-off-by:
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Adrian Hunter authored
The test uses the newly added cap_usr_time_zero and time_zero of perf_event_mmap_page. TSC from rdtsc is compared with the time from 2 perf events. The test passes if the calculated times are all in the correct order. Signed-off-by:
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Adrian Hunter authored
For modern CPUs, perf clock is directly related to TSC. TSC can be calculated from perf clock and vice versa using a simple calculation. Two of the three componenets of that calculation are already exported in struct perf_event_mmap_page. This patch exports the third. Signed-off-by:
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Adrian Hunter authored
The capabilities bits must not be "union'ed" together. Put them in a separate struct. Signed-off-by:
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Peter Zijlstra authored
Due to a discussion with Adrian I had a good look at the perf_event_type record layout and found the documentation to be somewhat unclear. Cc: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by:
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