From: Andrew Morton <akpm@linux-foundation.org>
To: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>,
Vlastimil Babka <vbabka@suse.cz>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [patch] mm, thp: fix defrag setting if newline is not used
Date: Thu, 16 Jan 2020 19:16:09 -0800 [thread overview]
Message-ID: <20200116191609.3972fd5301cf364a27381923@linux-foundation.org> (raw)
In-Reply-To: <alpine.DEB.2.21.2001141757490.108121@chino.kir.corp.google.com>
On Tue, 14 Jan 2020 17:58:36 -0800 (PST) David Rientjes <rientjes@google.com> wrote:
> If thp defrag setting "defer" is used and a newline is *not* used when
> writing to the sysfs file, this is interpreted as the "defer+madvise"
> option.
>
> This is because we do prefix matching and if five characters are written
> without a newline, the current code ends up comparing to the first five
> bytes of the "defer+madvise" option and using that instead.
>
> Find the length of what the user is writing and use that to guide our
> decision on which string comparison to do.
Gee, why is this code so complicated? Can't we just do
if (sysfs_streq(buf, "always")) {
...
} else if sysfs_streq(buf, "defer+madvise")) {
...
}
...
next prev parent reply other threads:[~2020-01-17 3:16 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-15 1:58 [patch] mm, thp: fix defrag setting if newline is not used David Rientjes
2020-01-15 12:45 ` Vlastimil Babka
2020-01-17 3:16 ` Andrew Morton [this message]
2020-01-17 8:24 ` Vlastimil Babka
2020-01-17 9:43 ` David Rientjes
2020-01-17 10:12 ` Vlastimil Babka
2020-01-17 22:11 ` [patch v2] " David Rientjes
2020-01-18 10:54 ` Vlastimil Babka
2020-01-19 1:04 ` Andrew Morton
2020-01-19 21:57 ` David Rientjes
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