From: Christoph Hellwig <hch@infradead.org>
To: Mel Gorman <mgorman@techsingularity.net>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Andrii Nakryiko <andrii.nakryiko@gmail.com>,
Michal Suchanek <msuchanek@suse.de>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
Yonghong Song <yhs@fb.com>,
John Fastabend <john.fastabend@gmail.com>,
KP Singh <kpsingh@kernel.org>,
open list <linux-kernel@vger.kernel.org>,
Arnaldo Carvalho de Melo <acme@redhat.com>,
Jiri Olsa <jolsa@kernel.org>, Hritik Vijay <hritikxx8@gmail.com>,
bpf <bpf@vger.kernel.org>, Linux-Net <netdev@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>
Subject: Re: [PATCH] mm/page_alloc: Work around a pahole limitation with zero-sized struct pagesets
Date: Thu, 27 May 2021 09:04:24 +0100 [thread overview]
Message-ID: <YK9SiLX1E1KAZORb@infradead.org> (raw)
In-Reply-To: <20210526080741.GW30378@techsingularity.net>
On Wed, May 26, 2021 at 09:07:41AM +0100, Mel Gorman wrote:
> + !defined(CONFIG_DEBUG_LOCK_ALLOC) && \
> + !defined(CONFIG_PAHOLE_HAS_ZEROSIZE_PERCPU_SUPPORT)
> + /*
> + * pahole 1.21 and earlier gets confused by zero-sized per-CPU
> + * variables and produces invalid BTF. Ensure that
> + * sizeof(struct pagesets) != 0 for older versions of pahole.
> + */
> + char __pahole_hack;
> + #warning "pahole too old to support zero-sized struct pagesets"
> +#endif
Err, hell no. We should not mess up the kernel for broken tools that
are not relevant to the kernel build itself ever.
next prev parent reply other threads:[~2021-05-27 8:05 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-26 8:07 [PATCH] mm/page_alloc: Work around a pahole limitation with zero-sized struct pagesets Mel Gorman
2021-05-26 8:16 ` David Hildenbrand
2021-05-26 8:33 ` (BTF) " Michal Suchánek
2021-05-26 9:00 ` Mel Gorman
2021-05-26 17:00 ` Andrii Nakryiko
2021-05-26 17:43 ` Michal Suchánek
2021-05-26 16:57 ` Andrii Nakryiko
2021-05-26 18:13 ` Mel Gorman
2021-05-26 18:41 ` Andrii Nakryiko
2021-05-27 8:04 ` Christoph Hellwig [this message]
2021-05-27 9:04 ` Mel Gorman
2021-05-27 9:18 ` Christoph Hellwig
2021-05-27 14:37 ` Andrii Nakryiko
2021-05-27 14:41 ` Andrii Nakryiko
2021-05-28 8:09 ` David Laight
2021-05-28 9:04 ` Mel Gorman
2021-05-28 9:49 ` David Laight
2021-05-28 9:56 ` Michal Suchánek
2021-05-28 13:09 ` David Laight
2021-05-30 0:46 ` Andrii Nakryiko
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