From: Mel Gorman <mgorman@techsingularity.net>
To: Andrii Nakryiko <andrii@kernel.org>
Cc: akpm@linux-foundation.org, bpf@vger.kernel.org,
msuchanek@suse.de, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, hritikxx8@gmail.com, jolsa@kernel.org,
kernel-team@fb.com, Arnaldo Carvalho de Melo <acme@redhat.com>,
Hao Luo <haoluo@google.com>
Subject: Re: [PATCH] kbuild: skip per-CPU BTF generation for pahole v1.18-v1.21
Date: Mon, 31 May 2021 10:34:23 +0100 [thread overview]
Message-ID: <20210531093422.GS30378@techsingularity.net> (raw)
In-Reply-To: <20210530002536.3193829-1-andrii@kernel.org>
On Sat, May 29, 2021 at 05:25:36PM -0700, Andrii Nakryiko wrote:
> Commit "mm/page_alloc: convert per-cpu list protection to local_lock"
> introduced a zero-sized per-CPU variable, which causes pahole to generate
> invalid BTF. Only pahole versions 1.18 through 1.21 are impacted, as before
> 1.18 pahole doesn't know anything about per-CPU variables, and 1.22 contains
> the proper fix for the issue.
>
> Luckily, pahole 1.18 got --skip_encoding_btf_vars option disabling BTF
> generation for per-CPU variables in anticipation of some unanticipated
> problems. So use this escape hatch to disable per-CPU var BTF info on those
> problematic pahole versions. Users relying on availability of per-CPU var BTFs
> would need to upgrade to pahole 1.22+, but everyone won't notice any
> regressions.
>
> Cc: Mel Gorman <mgorman@techsingularity.net>
> Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
> Cc: Hao Luo <haoluo@google.com>
> Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
--
Mel Gorman
SUSE Labs
parent reply other threads:[~2021-05-31 9:34 UTC|newest]
Thread overview: expand[flat|nested] mbox.gz Atom feed
[parent not found: <20210530002536.3193829-1-andrii@kernel.org>]
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=20210531093422.GS30378@techsingularity.net \
--to=mgorman@techsingularity.net \
--cc=acme@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=andrii@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=haoluo@google.com \
--cc=hritikxx8@gmail.com \
--cc=jolsa@kernel.org \
--cc=kernel-team@fb.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=msuchanek@suse.de \
/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).