[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-Id: <1222708257.4723.23.camel@localhost.localdomain>
Date: Mon, 29 Sep 2008 19:10:57 +0200
From: Gerald Schaefer <gerald.schaefer@...ibm.com>
To: linux-kernel@...r.kernel.org
Cc: linux-mm@...ck.org, schwidefsky@...ibm.com,
heiko.carstens@...ibm.com,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>,
Yasunori Goto <y-goto@...fujitsu.com>,
Mel Gorman <mel@....ul.ie>, Andy Whitcroft <apw@...dowen.org>,
Andrew Morton <akpm@...ux-foundation.org>
Subject: setup_per_zone_pages_min(): zone->lock vs. zone->lru_lock
Hi,
is zone->lru_lock really the right lock to take in setup_per_zone_pages_min()?
All other functions in mm/page_alloc.c take zone->lock instead, for working
with page->lru free-list or PageBuddy().
setup_per_zone_pages_min() eventually calls move_freepages(), which is also
manipulating the page->lru free-list and checking for PageBuddy(). Both
should be protected by zone->lock instead of zone->lru_lock, if I understood
that right, or else there could be a race with the other functions in
mm/page_alloc.c.
We ran into a list corruption bug in free_pages_bulk() once, during memory
hotplug stress test, but cannot reproduce it easily. So I cannot verify if
using zone->lock instead of zone->lru_lock would fix it, but to me it looks
like this may be the problem.
Any thoughts?
BTW, I also wonder if a spin_lock_irq() would be enough, instead of
spin_lock_irqsave(), because this function should never be called from
interrupt context, right?
Thanks,
Gerald
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists