From: Arjan van de Ven <arjanv@redhat.com>
To: Peter Zaitsev <pz@spylog.ru>, linux-kernel@vger.kernel.org
Subject: Re: Is Swapping on software RAID1 possible in linux 2.4 ?
Date: Thu, 05 Jul 2001 14:42:06 +0100 [thread overview]
Message-ID: <3B446EAE.E216448D@redhat.com> (raw)
In-Reply-To: <1011478953412.20010705152412@spylog.ru> <15172.22988.643481.421716@notabene.cse.unsw.edu.au> <11486070195.20010705172249@spylog.ru>
Peter Zaitsev wrote:
>
> That's why I thought this problem is related to raid1 swapping I'm
> using.
Well there is the potential problem that RAID1 has that it can't avoid
allocating
memory in some occasions, for the 2nd bufferhead. ATARAID raid0 has the
same problem for
now, and there is no real solution to this. You can pre-allocate a bunch
of bufferheads,
but under high load you will run out of those, no matter how many you
pre-allocate.
Of course you can then wait for the "in flight" ones to become available
again, and that is
the best thing I've come up with so far. It would be nice if the 3
subsystems that need such
bufferheads now (MD RAID1, ATARAID RAID0 and the bouncebuffer(head)
code) could share their
pool.
Greetings,
Arjan van de Ven
next prev parent reply other threads:[~2001-07-05 13:42 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <mailman.994340644.23368.linux-kernel2news@redhat.com>
2001-07-05 11:24 ` Is Swapping on software RAID1 possible in linux 2.4 ? Peter Zaitsev
2001-07-05 12:13 ` Neil Brown
2001-07-05 13:22 ` Re[2]: " Peter Zaitsev
2001-07-05 13:42 ` Arjan van de Ven [this message]
2001-07-05 18:56 ` Pete Zaitcev
2001-07-12 1:14 ` Re[2]: " Neil Brown
2001-07-12 1:48 ` Andrew Morton
2001-07-12 3:22 ` Neil Brown
2001-07-12 4:53 ` Andrew Morton
2001-07-05 14:54 ` Nick DeClario
2001-07-05 15:12 ` Joseph Bueno
2001-07-11 12:08 ` Paul Jakma
2001-07-06 9:38 ` Re[2]: " Peter Zaitsev
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