From: James Clark <james.clark@arm.com>
To: Leo Yan <leo.yan@linaro.org>, Yang Shi <shy828301@gmail.com>
Cc: linux-perf-users@vger.kernel.org,
LAK <linux-arm-kernel@lists.infradead.org>,
coresight@lists.linaro.org,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
mathieu.poirier@linaro.org, adrian.hunter@intel.com,
Jiri Olsa <jolsa@kernel.org>,
acme@redhat.com, mike.leach@linaro.org,
Will Deacon <will@kernel.org>,
suzuki.poulose@arm.com
Subject: Re: [BUG] perf: No samples found when using kcore + coresight
Date: Wed, 29 Mar 2023 17:08:44 +0100 [thread overview]
Message-ID: <64db6d95-8aca-48cc-80e1-e68211922071@arm.com> (raw)
In-Reply-To: <20230314003610.GD2426758@leoy-yangtze.lan>
On 14/03/2023 00:36, Leo Yan wrote:
> On Mon, Mar 13, 2023 at 11:15:44AM -0700, Yang Shi wrote:
>
> [...]
>
>>> Just a quick summary, here we have two issues:
>>>
>>> - With command:
>>> perf record -e cs_etm/@tmc_etf63/k --kcore --per-thread \
>>> -- taskset --cpu-list 1 uname",
>>>
>>> perf doesn't enable "text poke" attribution.
>>
>> No, it enables "text poke" and perf fails to decode coresight trace
>> data too. It doesn't matter whether "--kcore" is after or before "-e
>> cs/etm/@tmc_etf63/k".
>
> Understand now. Thanks for correction, if so we can ignore this one.
>
> Leo
To me it looks like it's only --per-thread and --kcore together that
cause the issue. I can't see if that was mentioned previously in this
thread.
If it is --per-thread that's causing the issue then I think I have an
idea why it might be. There are some assumptions and different paths
taken in decoding in that mode that aren't correct. It causes some other
issues to do with ordering and timestamps as well and I wanted to fix it
previously. I wouldn't say that the text-poke change has caused a
regression, as decoding in this mode was always a bit buggy.
Maybe this is another reason to fix it properly.
next prev parent reply other threads:[~2023-03-29 16:21 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CAHbLzkrJQTrYBtPkf=jf3OpQ-yBcJe7XkvQstX9j2frz4WF-SQ@mail.gmail.com>
2023-03-07 10:32 ` [BUG] perf: No samples found when using kcore + coresight James Clark
2023-03-07 19:45 ` Yang Shi
2023-03-08 19:56 ` Yang Shi
2023-03-09 11:38 ` Leo Yan
[not found] ` <CAHbLzkpvLHnyL5J5kB_ke3CWVq2=MOEdEQsGex56+Esfgqh1=g@mail.gmail.com>
2023-03-13 12:14 ` Leo Yan
2023-03-13 18:15 ` Yang Shi
2023-03-14 0:36 ` Leo Yan
2023-03-28 0:53 ` Yang Shi
2023-03-28 8:59 ` James Clark
2023-03-28 16:16 ` Yang Shi
2023-03-29 16:08 ` James Clark [this message]
2023-03-29 23:25 ` Yang Shi
2023-03-30 8:17 ` James Clark
2023-03-29 16:11 ` James Clark
2023-03-30 10:36 ` James Clark
2023-03-30 19:54 ` Yang Shi
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=64db6d95-8aca-48cc-80e1-e68211922071@arm.com \
--to=james.clark@arm.com \
--cc=acme@redhat.com \
--cc=adrian.hunter@intel.com \
--cc=coresight@lists.linaro.org \
--cc=jolsa@kernel.org \
--cc=leo.yan@linaro.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-perf-users@vger.kernel.org \
--cc=mathieu.poirier@linaro.org \
--cc=mike.leach@linaro.org \
--cc=shy828301@gmail.com \
--cc=suzuki.poulose@arm.com \
--cc=will@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).