From: Tao Chen <chen.dylane@linux.dev>
To: Yonghong Song <yonghong.song@linux.dev>,
peterz@infradead.org, mingo@redhat.com, acme@kernel.org,
namhyung@kernel.org, mark.rutland@arm.com,
alexander.shishkin@linux.intel.com, jolsa@kernel.org,
irogers@google.com, adrian.hunter@intel.com,
kan.liang@linux.intel.com, Andrii Nakryiko <andrii@kernel.org>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Eduard Zingerman <eddyz87@gmail.com>, Song Liu <song@kernel.org>,
Martin KaFai Lau <martin.lau@linux.dev>
Cc: linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org,
bpf@vger.kernel.org
Subject: Re: [PATCH bpf-next v6 2/2] bpf: Hold the perf callchain entry until used completely
Date: Wed, 26 Nov 2025 17:29:12 +0800 [thread overview]
Message-ID: <7b82e322-eab7-4fc2-9de1-d10ad8251378@linux.dev> (raw)
In-Reply-To: <c41372ad-1591-4f2b-a786-bc0e19f8425c@linux.dev>
在 2025/11/14 00:01, Yonghong Song 写道:
>
>
> On 11/12/25 8:31 AM, Tao Chen wrote:
>> As Alexei noted, get_perf_callchain() return values may be reused
>> if a task is preempted after the BPF program enters migrate disable
>> mode. The perf_callchain_entres has a small stack of entries, and
>> we can reuse it as follows:
>>
>> 1. get the perf callchain entry
>> 2. BPF use...
>> 3. put the perf callchain entry
>>
>> And Peter suggested that get_recursion_context used with preemption
>> disabled, so we should disable preemption at BPF side.
>>
>> Signed-off-by: Tao Chen <chen.dylane@linux.dev>
>
> Acked-by: Yonghong Song <yonghong.song@linux.dev>
>
Hi eBPF maintainers,
This patch appears to have missed the eBPF maintainers on the list,
please review it again, thanks.
--
Best Regards
Tao Chen
next prev parent reply other threads:[~2025-11-26 9:29 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-12 16:31 [PATCH bpf-next v6 0/2] Pass external callchain entry to get_perf_callchain Tao Chen
2025-11-12 16:31 ` [PATCH bpf-next v6 1/2] perf: Refactor get_perf_callchain Tao Chen
2025-11-12 16:31 ` [PATCH bpf-next v6 2/2] bpf: Hold the perf callchain entry until used completely Tao Chen
2025-11-13 16:01 ` Yonghong Song
2025-11-26 9:29 ` Tao Chen [this message]
2025-12-03 9:33 ` Tao Chen
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=7b82e322-eab7-4fc2-9de1-d10ad8251378@linux.dev \
--to=chen.dylane@linux.dev \
--cc=acme@kernel.org \
--cc=adrian.hunter@intel.com \
--cc=alexander.shishkin@linux.intel.com \
--cc=andrii@kernel.org \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=eddyz87@gmail.com \
--cc=irogers@google.com \
--cc=jolsa@kernel.org \
--cc=kan.liang@linux.intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-perf-users@vger.kernel.org \
--cc=mark.rutland@arm.com \
--cc=martin.lau@linux.dev \
--cc=mingo@redhat.com \
--cc=namhyung@kernel.org \
--cc=peterz@infradead.org \
--cc=song@kernel.org \
--cc=yonghong.song@linux.dev \
/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).