From: Andrew Morton <akpm@linux-foundation.org>
To: Shaohua Li <shli@kernel.org>
Cc: Hugh Dickins <hughd@google.com>,
Holger Kiehl <Holger.Kiehl@dwd.de>,
"Martin K. Petersen" <martin.petersen@oracle.com>,
linux-mm@kvack.org
Subject: Re: [RFC]swap: don't do discard if no discard option added
Date: Tue, 20 Mar 2012 21:56:47 -0700 [thread overview]
Message-ID: <20120320215647.f1268b05.akpm@linux-foundation.org> (raw)
In-Reply-To: <CANejiEUyPSNQ7q85ZDz-B3iHikHLgZLBNOF-p4evkxjGo5+M0g@mail.gmail.com>
On Wed, 21 Mar 2012 12:31:47 +0800 Shaohua Li <shli@kernel.org> wrote:
> But on
> the other hand, if user doesn't explictly enable discard, why enable
> it? Like fs, we didn't do runtime discard and only run trim occasionally
> since discard is slow.
This. Neither the swapon manpage nor the SWAP_FLAG_DISCARD comment nor
.c code comments nor the 339944663 changelog explain why we do a single
discard at swapon() time and then never again.
It sure *looks* like a bug. If it isn't then some explanation is sorely
needed.
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next prev parent reply other threads:[~2012-03-21 4:53 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-20 12:34 [RFC]swap: don't do discard if no discard option added Shaohua Li
2012-03-20 18:21 ` Holger Kiehl
2012-03-20 19:42 ` Andrew Morton
2012-03-21 3:57 ` Hugh Dickins
2012-03-21 4:31 ` Shaohua Li
2012-03-21 4:56 ` Andrew Morton [this message]
2012-03-23 11:23 ` Hugh Dickins
2012-03-23 11:00 ` Hugh Dickins
2012-03-21 17:55 ` Holger Kiehl
2012-03-23 11:38 ` Hugh Dickins
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