| 77c9ad0c | 11-Oct-2024 |
Tomas Glozar <tglozar@redhat.com> |
rtla/timerlat: Make timerlat_top_cpu->*_count unsigned long long
[ Upstream commit 4eba4723c5254ba8251ecb7094a5078d5c300646 ]
Most fields of struct timerlat_top_cpu are unsigned long long, but the
rtla/timerlat: Make timerlat_top_cpu->*_count unsigned long long
[ Upstream commit 4eba4723c5254ba8251ecb7094a5078d5c300646 ]
Most fields of struct timerlat_top_cpu are unsigned long long, but the
fields {irq,thread,user}_count are int (32-bit signed).
This leads to overflow when tracing on a large number of CPUs for a long
enough time:
$ rtla timerlat top -a20 -c 1-127 -d 12h
...
0 12:00:00 | IRQ Timer Latency (us) | Thread Timer Latency (us)
CPU COUNT | cur min avg max | cur min avg max
1 #43200096 | 0 0 1 2 | 3 2 6 12
...
127 #43200096 | 0 0 1 2 | 3 2 5 11
ALL #119144 e4 | 0 5 4 | 2 28 16
The average latency should be 0-1 for IRQ and 5-6 for thread, but is
reported as 5 and 28, about 4 to 5 times more, due to the count
overflowing when summed over all CPUs: 43200096 * 127 = 5486412192,
however, 1191444898 (= 5486412192 mod MAX_INT) is reported instead, as
seen on the last line of the output, and the averages are thus ~4.6
times higher than they should be (5486412192 / 1191444898 = ~4.6).
Fix the issue by changing {irq,thread,user}_count fields to unsigned
long long, similarly to other fields in struct timerlat_top_cpu and to
the count variable in timerlat_top_print_sum.
Link: https://lore.kernel.org/20241011121015.2868751-1-tglozar@redhat.com
Reported-by: Attila Fazekas <afazekas@redhat.com>
Signed-off-by: Tomas Glozar <tglozar@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
show more ...
|
| 42524cc5 | 24-Apr-2024 |
Daniel Bristot de Oliveira <bristot@kernel.org> |
rtla/auto-analysis: Replace \t with spaces
commit a40e5e4dd0207485dee75e2b8e860d5853bcc5f7 upstream.
When copying timerlat auto-analysis from a terminal to some web pages or
chats, the \t are being
rtla/auto-analysis: Replace \t with spaces
commit a40e5e4dd0207485dee75e2b8e860d5853bcc5f7 upstream.
When copying timerlat auto-analysis from a terminal to some web pages or
chats, the \t are being replaced with a single ' ' or ' ', breaking
the output.
For example:
## CPU 3 hit stop tracing, analyzing it ##
IRQ handler delay: 1.30 us (0.11 %)
IRQ latency: 1.90 us
Timerlat IRQ duration: 3.00 us (0.24 %)
Blocking thread: 1223.16 us (99.00 %)
insync:4048 1223.16 us
IRQ interference 4.93 us (0.40 %)
local_timer:236 4.93 us
------------------------------------------------------------------------
Thread latency: 1235.47 us (100%)
Replace \t with spaces to avoid this problem.
Link: https://lkml.kernel.org/r/ec7ed2b2809c22ab0dfc8eb7c805ab9cddc4254a.1713968967.git.bristot@kernel.org
Cc: stable@vger.kernel.org
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Juri Lelli <juri.lelli@redhat.com>
Fixes: 27e348b221f6 ("rtla/timerlat: Add auto-analysis core")
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
show more ...
|
| f0542eb7 | 06-Feb-2024 |
Daniel Bristot de Oliveira <bristot@kernel.org> |
tools/rtla: Fix uninitialized bucket/data->bucket_size warning
commit 64dc40f7523369912d7adb22c8cb655f71610505 upstream.
When compiling rtla with clang, I am getting the following warnings:
$ make
tools/rtla: Fix uninitialized bucket/data->bucket_size warning
commit 64dc40f7523369912d7adb22c8cb655f71610505 upstream.
When compiling rtla with clang, I am getting the following warnings:
$ make HOSTCC=clang CC=clang LLVM_IAS=1
[..]
clang -O -g -DVERSION=\"6.8.0-rc3\" -flto=auto -fexceptions
-fstack-protector-strong -fasynchronous-unwind-tables
-fstack-clash-protection -Wall -Werror=format-security
-Wp,-D_FORTIFY_SOURCE=2 -Wp,-D_GLIBCXX_ASSERTIONS
$(pkg-config --cflags libtracefs)
-c -o src/osnoise_hist.o src/osnoise_hist.c
src/osnoise_hist.c:138:6: warning: variable 'bucket' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
138 | if (data->bucket_size)
| ^~~~~~~~~~~~~~~~~
src/osnoise_hist.c:149:6: note: uninitialized use occurs here
149 | if (bucket < entries)
| ^~~~~~
src/osnoise_hist.c:138:2: note: remove the 'if' if its condition is always true
138 | if (data->bucket_size)
| ^~~~~~~~~~~~~~~~~~~~~~
139 | bucket = duration / data->bucket_size;
src/osnoise_hist.c:132:12: note: initialize the variable 'bucket' to silence this warning
132 | int bucket;
| ^
| = 0
1 warning generated.
[...]
clang -O -g -DVERSION=\"6.8.0-rc3\" -flto=auto -fexceptions
-fstack-protector-strong -fasynchronous-unwind-tables
-fstack-clash-protection -Wall -Werror=format-security
-Wp,-D_FORTIFY_SOURCE=2 -Wp,-D_GLIBCXX_ASSERTIONS
$(pkg-config --cflags libtracefs)
-c -o src/timerlat_hist.o src/timerlat_hist.c
src/timerlat_hist.c:181:6: warning: variable 'bucket' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
181 | if (data->bucket_size)
| ^~~~~~~~~~~~~~~~~
src/timerlat_hist.c:204:6: note: uninitialized use occurs here
204 | if (bucket < entries)
| ^~~~~~
src/timerlat_hist.c:181:2: note: remove the 'if' if its condition is always true
181 | if (data->bucket_size)
| ^~~~~~~~~~~~~~~~~~~~~~
182 | bucket = latency / data->bucket_size;
src/timerlat_hist.c:175:12: note: initialize the variable 'bucket' to silence this warning
175 | int bucket;
| ^
| = 0
1 warning generated.
This is a legit warning, but data->bucket_size is always > 0 (see
timerlat_hist_parse_args()), so the if is not necessary.
Remove the unneeded if (data->bucket_size) to avoid the warning.
Link: https://lkml.kernel.org/r/6e1b1665cd99042ae705b3e0fc410858c4c42346.1707217097.git.bristot@kernel.org
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Bill Wendling <morbo@google.com>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Donald Zickus <dzickus@redhat.com>
Fixes: 1eeb6328e8b3 ("rtla/timerlat: Add timerlat hist mode")
Fixes: 829a6c0b5698 ("rtla/osnoise: Add the hist mode")
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
show more ...
|
| 7c3611ca | 02-Feb-2024 |
John Kacur <jkacur@redhat.com> |
tools/rtla: Exit with EXIT_SUCCESS when help is invoked
commit b5f319360371087d52070d8f3fc7789e80ce69a6 upstream.
Fix rtla so that the following commands exit with 0 when help is invoked
rtla osno
tools/rtla: Exit with EXIT_SUCCESS when help is invoked
commit b5f319360371087d52070d8f3fc7789e80ce69a6 upstream.
Fix rtla so that the following commands exit with 0 when help is invoked
rtla osnoise top -h
rtla osnoise hist -h
rtla timerlat top -h
rtla timerlat hist -h
Link: https://lore.kernel.org/linux-trace-devel/20240203001607.69703-1-jkacur@redhat.com
Cc: stable@vger.kernel.org
Fixes: 1eeb6328e8b3 ("rtla/timerlat: Add timerlat hist mode")
Signed-off-by: John Kacur <jkacur@redhat.com>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
show more ...
|
| 8a585914 | 06-Feb-2024 |
Daniel Bristot de Oliveira <bristot@kernel.org> |
tools/rtla: Fix clang warning about mount_point var size
commit 30369084ac6e27479a347899e74f523e6ca29b89 upstream.
clang is reporting this warning:
$ make HOSTCC=clang CC=clang LLVM_IAS=1
[...]
cl
tools/rtla: Fix clang warning about mount_point var size
commit 30369084ac6e27479a347899e74f523e6ca29b89 upstream.
clang is reporting this warning:
$ make HOSTCC=clang CC=clang LLVM_IAS=1
[...]
clang -O -g -DVERSION=\"6.8.0-rc3\" -flto=auto -fexceptions
-fstack-protector-strong -fasynchronous-unwind-tables
-fstack-clash-protection -Wall -Werror=format-security
-Wp,-D_FORTIFY_SOURCE=2 -Wp,-D_GLIBCXX_ASSERTIONS
$(pkg-config --cflags libtracefs) -c -o src/utils.o src/utils.c
src/utils.c:548:66: warning: 'fscanf' may overflow; destination buffer in argument 3 has size 1024, but the corresponding specifier may require size 1025 [-Wfortify-source]
548 | while (fscanf(fp, "%*s %" STR(MAX_PATH) "s %99s %*s %*d %*d\n", mount_point, type) == 2) {
| ^
Increase mount_point variable size to MAX_PATH+1 to avoid the overflow.
Link: https://lkml.kernel.org/r/1b46712e93a2f4153909514a36016959dcc4021c.1707217097.git.bristot@kernel.org
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Bill Wendling <morbo@google.com>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Donald Zickus <dzickus@redhat.com>
Fixes: a957cbc02531 ("rtla: Add -C cgroup support")
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
show more ...
|
| daa5e6a4 | 07-Feb-2024 |
limingming3 <limingming890315@gmail.com> |
tools/rtla: Replace setting prio with nice for SCHED_OTHER
commit 14f08c976ffe0d2117c6199c32663df1cbc45c65 upstream.
Since the sched_priority for SCHED_OTHER is always 0, it makes no
sence to set i
tools/rtla: Replace setting prio with nice for SCHED_OTHER
commit 14f08c976ffe0d2117c6199c32663df1cbc45c65 upstream.
Since the sched_priority for SCHED_OTHER is always 0, it makes no
sence to set it.
Setting nice for SCHED_OTHER seems more meaningful.
Link: https://lkml.kernel.org/r/20240207065142.1753909-1-limingming3@lixiang.com
Cc: stable@vger.kernel.org
Fixes: b1696371d865 ("rtla: Helper functions for rtla")
Signed-off-by: limingming3 <limingming3@lixiang.com>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
show more ...
|
| e8c44d3b | 15-Sep-2023 |
Daniel Bristot de Oliveira <bristot@kernel.org> |
rtla/timerlat: Do not stop user-space if a cpu is offline
If no CPU list is passed, timerlat in user-space will dispatch
one thread per sysconf(_SC_NPROCESSORS_CONF). However, not all
CPU might be a
rtla/timerlat: Do not stop user-space if a cpu is offline
If no CPU list is passed, timerlat in user-space will dispatch
one thread per sysconf(_SC_NPROCESSORS_CONF). However, not all
CPU might be available, for instance, if HT is disabled.
Currently, rtla timerlat is stopping the session if an user-space
thread cannot set affinity to a CPU, or if a running user-space
thread is killed. However, this is too restrictive.
So, reduce the error to a debug message, and rtla timerlat run as
long as there is at least one user-space thread alive.
Link: https://lore.kernel.org/lkml/59cf2c882900ab7de91c6ee33b382ac7fa6b4ed0.1694781909.git.bristot@kernel.org
Fixes: cdca4f4e5e8e ("rtla/timerlat_top: Add timerlat user-space support")
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
show more ...
|
| 301deca0 | 04-Aug-2023 |
Daniel Bristot de Oliveira <bristot@kernel.org> |
rtla/timerlat_aa: Fix previous IRQ delay for IRQs that happens after thread sample
timerlat auto-analysis takes note of all IRQs, before or after the
execution of the timerlat thread.
Because we ca
rtla/timerlat_aa: Fix previous IRQ delay for IRQs that happens after thread sample
timerlat auto-analysis takes note of all IRQs, before or after the
execution of the timerlat thread.
Because we cannot go backward in the trace (we will fix it when
moving to trace-cmd lib?), timerlat aa take note of the last IRQ
execution in the waiting for the IRQ state, and then print it
if it is executed after the expected timer IRQ starting time.
After the thread sample, the timerlat starts recording the next IRQs as
"previous" irq for the next occurrence.
However, if an IRQ happens after the thread measurement but before the
tracing stops, it is classified as a previous IRQ. That is not
wrong, as it can be "previous" for the subsequent activation. What is
wrong is considering it as a potential source for the last activation.
Ignore the IRQ interference that happens after the IRQ starting time for
now. A future improvement for timerlat can be either keeping a list of
previous IRQ execution or using the trace-cmd library. Still, it requires
further investigation - it is a new feature.
Link: https://lore.kernel.org/lkml/a44a3f5c801dcc697bacf7325b65d4a5b0460537.1691162043.git.bristot@kernel.org
Fixes: 27e348b221f6 ("rtla/timerlat: Add auto-analysis core")
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
show more ...
|
| 6c73daf2 | 04-Aug-2023 |
Daniel Bristot de Oliveira <bristot@kernel.org> |
rtla/timerlat_aa: Fix negative IRQ delay
When estimating the IRQ timer delay, we are dealing with two different
clock sources: the external clock source that timerlat uses as a reference
and the clo
rtla/timerlat_aa: Fix negative IRQ delay
When estimating the IRQ timer delay, we are dealing with two different
clock sources: the external clock source that timerlat uses as a reference
and the clock used by the tracer. There are also two moments: the time
reading the clock and the timer in which the event is placed in the
buffer (the trace event timestamp).
If the processor is slow or there is some hardware noise, the difference
between the timestamp and the external clock, read can be longer than the
IRQ handler delay, resulting in a negative time.
If so, set IRQ to start delay as 0. In the end, it is less near-zero and relevant
then the noise.
Link: https://lore.kernel.org/lkml/a066fb667c7136d86dcddb3c7ccd72587db3e7c7.1691162043.git.bristot@kernel.org
Fixes: 27e348b221f6 ("rtla/timerlat: Add auto-analysis core")
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
show more ...
|
| ed774f74 | 06-Jun-2023 |
Daniel Bristot de Oliveira <bristot@kernel.org> |
rtla/timerlat_hist: Add timerlat user-space support
Add the support for running timerlat threads in user-space. In this
mode, enabled with -u/--user-threads, timerlat dispatches user-space
processes
rtla/timerlat_hist: Add timerlat user-space support
Add the support for running timerlat threads in user-space. In this
mode, enabled with -u/--user-threads, timerlat dispatches user-space
processes that will loop in the timerlat_fd, measuring the overhead
for going to user-space and then returning to the kernel - in addition
to the existing measurements.
Here is one example of the tool's output with -u enabled:
$ sudo timerlat hist -u -c 1-3 -d 600
# RTLA timerlat histogram
# Time unit is microseconds (us)
# Duration: 0 00:10:01
Index IRQ-001 Thr-001 Usr-001 IRQ-002 Thr-002 Usr-002 IRQ-003 Thr-003 Usr-003
0 477555 0 0 425287 0 0 474357 0 0
1 122385 7998 0 174616 1921 0 125412 3138 0
2 47 587376 492150 89 594717 447830 147 593463 454872
3 11 2549 101930 7 2682 145580 64 2530 138680
4 3 1954 2833 1 463 4917 11 548 4656
5 0 60 1037 0 138 1117 6 179 1130
6 0 26 1837 0 38 277 1 76 339
7 0 15 143 0 28 147 2 37 156
8 0 10 23 0 11 75 0 12 80
9 0 7 17 0 0 26 0 11 42
10 0 2 11 0 0 18 0 2 20
11 0 0 7 0 1 8 0 2 12
12 0 0 6 0 1 4 0 2 8
13 0 1 3 0 0 0 0 0 1
14 0 1 0 0 0 1 0 0 2
15 0 1 0 0 0 0 0 0 2
16 0 1 2 0 0 0 0 0 0
17 0 0 1 0 0 0 0 0 0
19 0 0 1 0 0 0 0 0 0
over: 0 0 0 0 0 0 0 0 0
count: 600001 600001 600001 600000 600000 600000 600000 600000 600000
min: 0 1 2 0 1 2 0 1 2
avg: 0 1 2 0 2 2 0 2 2
max: 4 16 19 4 12 14 7 12 15
The tuning setup like -p or -C work for the user-space threads as well.
Link: https://lkml.kernel.org/r/b6a042d55003c4a67ff7dce28d96044b7044f00d.1686066600.git.bristot@kernel.org
Cc: William White <chwhite@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
show more ...
|
| cdca4f4e | 06-Jun-2023 |
Daniel Bristot de Oliveira <bristot@kernel.org> |
rtla/timerlat_top: Add timerlat user-space support
Add the support for running timerlat threads in user-space. In this
mode, enabled with -u/--user-threads, timerlat dispatches user-space
processes
rtla/timerlat_top: Add timerlat user-space support
Add the support for running timerlat threads in user-space. In this
mode, enabled with -u/--user-threads, timerlat dispatches user-space
processes that will loop in the timerlat_fd, measuring the overhead
for going to user-space and then returning to the kernel - in addition
to the existing measurements.
Here is one example of the tool's output with -u enabled:
$ sudo timerlat top -u -d 600 -q
Timer Latency
0 00:10:01 | IRQ Timer Latency (us) | Thread Timer Latency (us) | Ret user Timer Latency (us)
CPU COUNT | cur min avg max | cur min avg max | cur min avg max
0 #600001 | 0 0 0 3 | 2 1 2 9 | 3 2 3 15
1 #600001 | 0 0 0 2 | 2 1 2 13 | 2 2 3 18
2 #600001 | 0 0 0 10 | 2 1 2 16 | 3 2 3 20
3 #600001 | 0 0 0 7 | 2 1 2 10 | 3 2 3 11
4 #600000 | 0 0 0 16 | 2 1 2 41 | 3 2 3 58
5 #600000 | 0 0 0 3 | 2 1 2 10 | 3 2 3 13
6 #600000 | 0 0 0 5 | 2 1 2 7 | 3 2 3 10
7 #600000 | 0 0 0 1 | 2 1 2 7 | 3 2 3 10
The tuning setup like -p or -C work for the user-space threads as well.
Link: https://lkml.kernel.org/r/758ad2292a0a1d884138d08219e1a0f572d257a2.1686066600.git.bristot@kernel.org
Cc: William White <chwhite@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
show more ...
|
| 7bc4d308 | 06-Jun-2023 |
Daniel Bristot de Oliveira <bristot@kernel.org> |
rtla/hwnoise: Reduce runtime to 75%
osnoise runs 100% of time by default. It makes sense because osnoise
is preemptive. hwnoise checks preemption once a second, so it
reduces system progress.
Reduc
rtla/hwnoise: Reduce runtime to 75%
osnoise runs 100% of time by default. It makes sense because osnoise
is preemptive. hwnoise checks preemption once a second, so it
reduces system progress.
Reduce runtime to 75% to avoid problems by default. I added a Fixes
as it might avoid problems for first time users as it lands on distros.
Link: https://lkml.kernel.org/r/af0b7113ffc00031b9af4bb40ef5889a27dadf8c.1686066600.git.bristot@kernel.org
Cc: William White <chwhite@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Fixes: 1f428356c38d ("rtla: Add hwnoise tool")
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
show more ...
|
| 57cf76ec | 06-Jun-2023 |
Daniel Bristot de Oliveira <bristot@kernel.org> |
rtla: Start the tracers after creating all instances
Group all start tracing after finishing creating all instances.
The tracing instance starts first for the case of hitting a stop
tracing while e
rtla: Start the tracers after creating all instances
Group all start tracing after finishing creating all instances.
The tracing instance starts first for the case of hitting a stop
tracing while enabling other instances. The trace instance is the
one with most valuable information.
Link: https://lkml.kernel.org/r/67da7a703a56f75d7cd46568525145a65501a7e8.1686066600.git.bristot@kernel.org
Cc: William White <chwhite@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
show more ...
|
| 2091336b | 06-Jun-2023 |
Daniel Bristot de Oliveira <bristot@kernel.org> |
rtla/timerlat_hist: Add auto-analysis support
Add auto-analysis to timerlat hist, including the --no-aa option to
reduce overhead and --dump-task. --aa-only was not added as it is
already on timerla
rtla/timerlat_hist: Add auto-analysis support
Add auto-analysis to timerlat hist, including the --no-aa option to
reduce overhead and --dump-task. --aa-only was not added as it is
already on timerlat top.
Link: https://lkml.kernel.org/r/c2693f47ee83e659a7723fed8035f5d2534f528e.1686066600.git.bristot@kernel.org
Cc: William White <chwhite@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
show more ...
|
| c66552be | 06-Jun-2023 |
Daniel Bristot de Oliveira <bristot@kernel.org> |
rtla/timerlat: Give timerlat auto analysis its own instance
Currently, the auto-analysis is attached to the timerlat top instance.
The idea was to avoid creating another instance just for that, so o
rtla/timerlat: Give timerlat auto analysis its own instance
Currently, the auto-analysis is attached to the timerlat top instance.
The idea was to avoid creating another instance just for that, so one
instance could be reused.
The drawback is that, by doing so, the auto-analysis run for the entire
session, consuming CPU time. On my 24 box CPUs for timerlat with a 100
us period consumed 50 % with auto analysis, but only 16 % without.
By creating an instance for auto-analysis, we can keep the processing
stopped until a stop tracing condition is hit. Once it happens,
timerlat auto-analysis can use its own trace instance to parse only
the end of the trace.
By doing so, auto-analysis stop consuming cpu time when it is not
needed.
If the --aa-only is passed, the timerlat top instance is reused for
auto analysis.
Link: https://lkml.kernel.org/r/346b7168c1bae552a415715ec6d23c129a43bdb7.1686066600.git.bristot@kernel.org
Cc: William White <chwhite@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
show more ...
|
| c58a3f8c | 06-Jun-2023 |
Daniel Bristot de Oliveira <bristot@kernel.org> |
rtla: Automatically move rtla to a house-keeping cpu
When the user sets -c <cpu-list> try to move rtla out of the <cpu-list>,
even without an -H option. This is useful to avoid having rtla
interferi
rtla: Automatically move rtla to a house-keeping cpu
When the user sets -c <cpu-list> try to move rtla out of the <cpu-list>,
even without an -H option. This is useful to avoid having rtla
interfering with the workload.
This works by removing <cpu-list> from rtla's current affinity.
If rtla fails to move itself away it is not that of a problem as this
is an automatic measure.
Link: https://lkml.kernel.org/r/c54304d90c777310fb85a3e658d1449173759aab.1686066600.git.bristot@kernel.org
Cc: William White <chwhite@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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