<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/tools/perf/builtin-top.c, branch linux-4.17.y</title>
<subtitle>Hosts the 0x221E linux distro kernel.</subtitle>
<id>https://universe.0xinfinity.dev/distro/kernel/atom?h=linux-4.17.y</id>
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<updated>2018-03-21T15:53:40Z</updated>
<entry>
<title>perf annotate: Move the default annotate options to the library</title>
<updated>2018-03-21T15:53:40Z</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2018-03-16T17:33:38Z</published>
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<id>urn:sha1:7f0b6fde3111aec82487662ccef5a4ebecb93381</id>
<content type='text'>
One more thing that goes from the TUI code to be used more widely,
for instance it'll affect the default options used by:

  perf annotate --stdio2

Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Jin Yao &lt;yao.jin@linux.intel.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Link: https://lkml.kernel.org/n/tip-0nsz0dm0akdbo30vgja2a10e@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf top: Fix top.call-graph config option reading</title>
<updated>2018-03-16T16:56:04Z</updated>
<author>
<name>Yisheng Xie</name>
<email>xieyisheng1@huawei.com</email>
</author>
<published>2018-03-12T11:25:56Z</published>
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<id>urn:sha1:a3a4a3b37c9b911af4c375b2475cea0fd2b84d38</id>
<content type='text'>
When trying to add the "call-graph" variable for top into the
.perfconfig file, like:

      [top]
            call-graph = fp

I that perf_top_config() do not parse this variable.

Fix it by calling perf_default_config() when the top.call-graph variable
is set.

Signed-off-by: Yisheng Xie &lt;xieyisheng1@huawei.com&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Fixes: b8cbb349061e ("perf config: Bring perf_default_config to the very beginning at main()")
Link: http://lkml.kernel.org/r/1520853957-36106-1-git-send-email-xieyisheng1@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf mmap: Simplify perf_mmap__read_init()</title>
<updated>2018-03-08T13:05:53Z</updated>
<author>
<name>Kan Liang</name>
<email>kan.liang@linux.intel.com</email>
</author>
<published>2018-03-06T15:36:07Z</published>
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<id>urn:sha1:b9bae2c841b73eac6bfed510bc24a3051754ff51</id>
<content type='text'>
It isn't necessary to pass the 'start', 'end' and 'overwrite' arguments
to perf_mmap__read_init().  The data is stored in the struct perf_mmap.

Discard the parameters.

Signed-off-by: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Suggested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Link: http://lkml.kernel.org/r/1520350567-80082-8-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf mmap: Simplify perf_mmap__read_event()</title>
<updated>2018-03-08T13:05:53Z</updated>
<author>
<name>Kan Liang</name>
<email>kan.liang@linux.intel.com</email>
</author>
<published>2018-03-06T15:36:06Z</published>
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<id>urn:sha1:0019dc87b928380e2c85fcd8694e512079d7b580</id>
<content type='text'>
It isn't necessary to pass the 'overwrite', 'start' and 'end' argument
to perf_mmap__read_event().  Discard them.

Signed-off-by: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Suggested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Link: http://lkml.kernel.org/r/1520350567-80082-7-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf mmap: Simplify perf_mmap__consume()</title>
<updated>2018-03-08T13:05:52Z</updated>
<author>
<name>Kan Liang</name>
<email>kan.liang@linux.intel.com</email>
</author>
<published>2018-03-06T15:36:05Z</published>
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<id>urn:sha1:d6ace3df43049a46aa1f5596c0c8d75433321437</id>
<content type='text'>
It isn't necessary to pass the 'overwrite' argument to
perf_mmap__consume().  Discard it.

Signed-off-by: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Suggested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Link: http://lkml.kernel.org/r/1520350567-80082-6-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf top: Allow asking for the maximum allowed sample rate</title>
<updated>2018-03-05T12:58:44Z</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2018-03-01T17:25:56Z</published>
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<id>urn:sha1:7831bf236505bcb2a0a1255e7f3e902a0cb732d6</id>
<content type='text'>
Add the handy '-F max' shortcut, just introduced to 'perf record', to
reading and using the kernel.perf_event_max_sample_rate value as the
user supplied sampling frequency:

Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Link: https://lkml.kernel.org/n/tip-hz04f296zccknnb5at06a6q0@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf top: Fix annoying fallback message on older kernels</title>
<updated>2018-02-26T19:04:08Z</updated>
<author>
<name>Kan Liang</name>
<email>Kan.liang@intel.com</email>
</author>
<published>2018-02-26T18:17:10Z</published>
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<id>urn:sha1:853745f5e6d95faaae6381c9a01dbd43de992fb3</id>
<content type='text'>
On older (e.g. v4.4) kernels, an annoying fallback message can be
observed in 'perf top':

	┌─Warning:──────────────────────┐
	│fall back to non-overwrite mode│
	│                               │
	│                               │
	│Press any key...               │
	└───────────────────────────────┘

The 'perf top' utility has been changed to overwrite mode since commit
ebebbf082357 ("perf top: Switch default mode to overwrite mode").

For older kernels which don't have overwrite mode support, 'perf top'
will fall back to non-overwrite mode and print out the fallback message
using ui__warning(), which needs user's input to close.

The fallback message is not critical for end users. Turning it to debug
message which is printed when running with -vv.

Reported-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Signed-off-by: Kan Liang &lt;kan.liang@intel.com&gt;
Cc: Kan Liang &lt;kan.liang@intel.com&gt;
Fixes: ebebbf082357 ("perf top: Switch default mode to overwrite mode")
Link: http://lkml.kernel.org/r/1519669030-176549-1-git-send-email-kan.liang@intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf top: Check the latency of perf_top__mmap_read()</title>
<updated>2018-02-15T12:57:06Z</updated>
<author>
<name>Kan Liang</name>
<email>kan.liang@intel.com</email>
</author>
<published>2018-01-18T21:26:32Z</published>
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<id>urn:sha1:8cc42de736b617827a4e7664fb8d7a325bc125bc</id>
<content type='text'>
The latency of perf_top__mmap_read() should be lower than refresh time.
If not, give some hints to reduce the latency.

Signed-off-by: Kan Liang &lt;kan.liang@intel.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Jin Yao &lt;yao.jin@linux.intel.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Link: http://lkml.kernel.org/r/1516310792-208685-18-git-send-email-kan.liang@intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf top: Switch default mode to overwrite mode</title>
<updated>2018-02-15T12:56:54Z</updated>
<author>
<name>Kan Liang</name>
<email>kan.liang@intel.com</email>
</author>
<published>2018-01-18T21:26:31Z</published>
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<id>urn:sha1:ebebbf082357f86cc84a4d46ce897a5750e41b7a</id>
<content type='text'>
perf_top__mmap_read() has a severe performance issue in the Knights
Landing/Mill platform, when monitoring heavy load systems. It costs
several minutes to finish, which is unacceptable.

Currently, 'perf top' uses the non overwrite mode. For non overwrite
mode, it tries to read everything in the ringbuffer and doesn't pause
it. Once there are lots of samples delivered persistently, the
processing time could be very long. Also, the latest samples could be
lost when the ringbuffer is full.

For overwrite mode, it takes a snapshot for the system by pausing the
ringbuffer, which could significantly reduce the processing time.  Also,
the overwrite mode always keep the latest samples.  Considering the real
time requirement for 'perf top', the overwrite mode is more suitable for
it.

Actually, 'perf top' was overwrite mode. It is changed to non overwrite
mode since commit 93fc64f14472 ("perf top: Switch to non overwrite
mode"). It's better to change it back to overwrite mode by default.

For the kernel which doesn't support overwrite mode, it will fall back
to non overwrite mode.

There would be some records lost in overwrite mode because of pausing
the ringbuffer. It has little impact for the accuracy of the snapshot
and can be tolerated.

For overwrite mode, unconditionally wait 100 ms before each snapshot. It
also reduces the overhead caused by pausing ringbuffer, especially on
light load system.

Signed-off-by: Kan Liang &lt;kan.liang@intel.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Jin Yao &lt;yao.jin@linux.intel.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Link: http://lkml.kernel.org/r/1516310792-208685-17-git-send-email-kan.liang@intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf top: Remove lost events checking</title>
<updated>2018-02-15T12:56:43Z</updated>
<author>
<name>Kan Liang</name>
<email>kan.liang@intel.com</email>
</author>
<published>2018-01-18T21:26:30Z</published>
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<id>urn:sha1:a1ff5b05e988ca3620027148cd61013408ea4194</id>
<content type='text'>
There would be some records lost in overwrite mode because of pausing
the ringbuffer. It has little impact for the accuracy of the snapshot
and could be tolerated by 'perf top'.

Remove the lost events checking.

Signed-off-by: Kan Liang &lt;kan.liang@intel.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Jin Yao &lt;yao.jin@linux.intel.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Link: http://lkml.kernel.org/r/1516310792-208685-16-git-send-email-kan.liang@intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
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