From: Artem Bityutskiy <dedekind1@gmail.com>
To: Grant Erickson <marathon96@gmail.com>
Cc: linux-mtd@lists.infradead.org,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] MTD: Retry Read/Write Transfer Buffer Allocations
Date: Mon, 04 Apr 2011 10:41:50 +0300 [thread overview]
Message-ID: <1301902910.2760.31.camel@localhost> (raw)
In-Reply-To: <1301902050.2760.23.camel@localhost>
On Mon, 2011-04-04 at 10:27 +0300, Artem Bityutskiy wrote:
> An third, as I wrote in my answer to Jarkko, allocating large contiguous
> buffers is bad for performance: if the system memory is fragmented and
> there is no such large contiguous areas, the kernel will start writing
> back dirty FS data, killing FS caches, shrinking caches and buggers,
> probably even swapping out applications. We do not want MTD to cause
> this at all.
s/buggers/buffers/
> Probably we can mitigate this with kmalloc flags. Now, I'm not sure what
> flags are the optimal, but I'd do:
>
> __GFP_NOWARN | __GFP_WAIT | __GFP_NORETRY
Of course I meant you should use special flags as long as you are
allocating more than 1 contiguous page. But the last PAGE_SIZE
allocation should be done with standard GFP_KERNEL flag.
--
Best Regards,
Artem Bityutskiy (Артём Битюцкий)
next prev parent reply other threads:[~2011-04-04 7:44 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-02 0:44 [PATCH] MTD: Retry Read/Write Transfer Buffer Allocations Grant Erickson
2011-04-04 7:27 ` Artem Bityutskiy
2011-04-04 7:41 ` Artem Bityutskiy [this message]
2011-04-04 16:05 ` Grant Erickson
2011-04-04 16:05 ` Grant Erickson
2011-04-05 4:39 ` Artem Bityutskiy
2011-04-05 4:39 ` Artem Bityutskiy
2011-04-04 18:19 ` [PATCH v2] " Grant Erickson
2011-04-05 4:39 ` Artem Bityutskiy
2011-04-05 15:54 ` Grant Erickson
2011-04-05 16:54 ` Artem Bityutskiy
2011-04-05 4:48 ` Artem Bityutskiy
-- strict thread matches above, loose matches on Subject: below --
2011-04-02 1:29 [PATCH] JFFS2: Retry Medium Scan " Grant Erickson
2011-04-04 18:39 ` [PATCH] MTD: Retry Read/Write Transfer " Grant Erickson
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