From: Eric Dumazet <eric.dumazet@gmail.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Vlastimil Babka <vbabka@suse.cz>,
Alexander Viro <viro@zeniv.linux.org.uk>,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, Michal Hocko <mhocko@kernel.org>,
netdev@vger.kernel.org
Subject: Re: [PATCH v2] fs/select: add vmalloc fallback for select(2)
Date: Mon, 26 Sep 2016 18:38:44 -0700 [thread overview]
Message-ID: <1474940324.28155.44.camel@edumazet-glaptop3.roam.corp.google.com> (raw)
In-Reply-To: <20160926170105.517f74cd67ecdd5ef73e1865@linux-foundation.org>
On Mon, 2016-09-26 at 17:01 -0700, Andrew Morton wrote:
> I don't share Eric's concerns about performance here. If the vmalloc()
> is called, we're about to write to that quite large amount of memory
> which we just allocated, and the vmalloc() overhead will be relatively
> low.
I did not care of the performance of this particular select() system
call really, but other cpus because of more TLB invalidations.
At least CONFIG_DEBUG_PAGEALLOC=y builds should be impacted, but maybe
we do not care.
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next prev parent reply other threads:[~2016-09-27 1:38 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-22 16:43 [PATCH v2] fs/select: add vmalloc fallback for select(2) Vlastimil Babka
2016-09-22 16:49 ` Eric Dumazet
2016-09-22 16:56 ` Vlastimil Babka
2016-09-22 17:07 ` Eric Dumazet
2016-09-22 17:55 ` Vlastimil Babka
2016-09-23 9:42 ` David Laight
2016-09-23 9:58 ` Vlastimil Babka
2016-09-23 13:35 ` David Laight
2016-09-26 10:01 ` Vlastimil Babka
2016-09-26 15:02 ` David Laight
2016-09-25 18:50 ` Andi Kleen
2016-09-27 0:01 ` Andrew Morton
2016-09-27 1:38 ` Eric Dumazet [this message]
2016-09-27 8:13 ` Vlastimil Babka
2016-09-27 13:34 ` Eric Dumazet
2016-09-27 8:06 ` Vlastimil Babka
2016-09-27 8:45 ` [PATCH v3] " Vlastimil Babka
2016-09-27 10:22 ` Michal Hocko
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