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Date: Mon, 04 May 2009 12:12:07 -0400
From: Rik van Riel <riel@redhat.com>
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To: Kyle Moffett <kyle@moffetthome.net>
CC: Lars Ellenberg <lars.ellenberg@linbit.com>,
       Philipp Reisner <philipp.reisner@linbit.com>,
       linux-kernel@vger.kernel.org, Jens Axboe <jens.axboe@oracle.com>,
       Greg KH <gregkh@suse.de>, Neil Brown <neilb@suse.de>,
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       Sam Ravnborg <sam@ravnborg.org>, Dave Jones <davej@redhat.com>,
       Nikanth Karthikesan <knikanth@suse.de>,
       Lars Marowsky-Bree <lmb@suse.de>,
       "Nicholas A. Bellinger" <nab@linux-iscsi.org>,
       Bart Van Assche <bart.vanassche@gmail.com>
Subject: Re: [PATCH 02/16] DRBD: lru_cache
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Kyle Moffett wrote:
> On Sun, May 3, 2009 at 8:48 PM, Kyle Moffett <kyle@moffetthome.net> wrote:
>> There are a couple trivial tunables you can apply to the model I
>> provided to dramatically change the effect of memory pressure on the
>> LRU:
>>
>> [...]
>>
> 
> Ooh, I forgot to mention another biggie:  There's a way to allocate a
> reserve pool of memory (I don't remember the exact API, sorry), which
> can be attached to a specific kmem_cache to be used by processes
> attempting writeout.  This would allow you to allocate more in-use
> elements to make forward progress, even if all of your existing
> elements are already in-use.

Lars,

is using a mempool for allocation, in combination with a
shrinker callback for freeing older entries an option for
DRBD?

It looks like that could get rid of a fair amount of custom infrastructure.

-- 
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