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Wed, 26 May 2021 11:41:52 -0700 (PDT) MIME-Version: 1.0 References: <20210526080741.GW30378@techsingularity.net> <20210526181306.GZ30378@techsingularity.net> In-Reply-To: <20210526181306.GZ30378@techsingularity.net> From: Andrii Nakryiko Date: Wed, 26 May 2021 11:41:41 -0700 Message-ID: Subject: Re: [PATCH] mm/page_alloc: Work around a pahole limitation with zero-sized struct pagesets To: Mel Gorman Cc: Andrew Morton , Michal Suchanek , Alexei Starovoitov , Daniel Borkmann , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , open list , Arnaldo Carvalho de Melo , Jiri Olsa , Hritik Vijay , bpf , Linux-Net , Linux-MM Content-Type: text/plain; charset="UTF-8" Authentication-Results: imf10.hostedemail.com; dkim=pass header.d=gmail.com header.s=20161025 header.b=G9uWbmyG; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf10.hostedemail.com: domain of andriinakryiko@gmail.com designates 209.85.219.171 as permitted sender) smtp.mailfrom=andriinakryiko@gmail.com X-Stat-Signature: zzsdbar918qf7dxcaw8rz5b581bz4kbr X-Rspamd-Queue-Id: AA09B40B8CF5 X-Rspamd-Server: rspam02 X-HE-Tag: 1622054506-365475 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, May 26, 2021 at 11:13 AM Mel Gorman wrote: > > On Wed, May 26, 2021 at 09:57:31AM -0700, Andrii Nakryiko wrote: > > > This patch checks for older versions of pahole and forces struct pagesets > > > to be non-zero sized as a workaround when CONFIG_DEBUG_INFO_BTF is set. A > > > warning is omitted so that distributions can update pahole when 1.22 > > > > s/omitted/emitted/ ? > > > > Yes. > > > > is released. > > > > > > Reported-by: Michal Suchanek > > > Reported-by: Hritik Vijay > > > Debugged-by: Andrii Nakryiko > > > Signed-off-by: Mel Gorman > > > --- > > > > Looks good! I verified that this does fix the issue on the latest > > linux-next tree, thanks! > > > > Excellent > > > One question, should > > > > Fixes: 5716a627517d ("mm/page_alloc: convert per-cpu list protection > > to local_lock") > > > > be added to facilitate backporting? > > > > The git commit is not stable because the patch "mm/page_alloc: convert > per-cpu list protection to local_lock" is in Andrew's mmotm tree which is Oh, I didn't know about this instability. > quilt based. I decided not to treat the patch as a fix because the patch is > not wrong as such, it's a limitation of an external tool. However, I would > expect both the problematic patch and the BTF workaround to go in during > the same merge window so backports to -stable should not be required. Yep, makes sense. > > > Either way: > > > > Acked-by: Andrii Nakryiko > > Tested-by: Andrii Nakryiko > > > > Thanks! > > -- > Mel Gorman > SUSE Labs