From: Andrea Arcangeli <aarcange@redhat.com>
To: Minchan Kim <minchan.kim@gmail.com>
Cc: Mel Gorman <mel@csn.ul.ie>,
Andrew Morton <akpm@linux-foundation.org>,
Arthur Marsh <arthur.marsh@internode.on.net>,
Clemens Ladisch <cladisch@googlemail.com>,
Linux-MM <linux-mm@kvack.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 2/2] mm: compaction: Minimise the time IRQs are disabled while isolating pages for migration
Date: Tue, 1 Mar 2011 00:07:12 +0100 [thread overview]
Message-ID: <20110228230712.GR22700@random.random> (raw)
In-Reply-To: <20110228230131.GB1896@barrios-desktop>
On Tue, Mar 01, 2011 at 08:01:31AM +0900, Minchan Kim wrote:
> I am not sure it's good if we release the lock whenever lru->lock was contended
> unconditionally? There are many kinds of lru_lock operations(add to lru,
> del from lru, isolation, reclaim, activation, deactivation and so on).
This is mostly to mirror cond_resched_lock (which actually uses
spin_needbreak but it's ok to have it also when preempt is off). I
doubt it makes a big difference but I tried to mirror
cond_resched_lock.
> Do we really need to release the lock whenever all such operations were contened?
> I think what we need is just spin_is_contended_irqcontext.
> Otherwise, please write down the comment for justifying for it.
What is spin_is_contended_irqcontext?
> This patch is for reducing for irq latency but do we have to check signal
> in irq hold time?
I think it's good idea to check the signal in case the loop is very
long and this is run in direct compaction context.
WARNING: multiple messages have this Message-ID (diff)
From: Andrea Arcangeli <aarcange@redhat.com>
To: Minchan Kim <minchan.kim@gmail.com>
Cc: Mel Gorman <mel@csn.ul.ie>,
Andrew Morton <akpm@linux-foundation.org>,
Arthur Marsh <arthur.marsh@internode.on.net>,
Clemens Ladisch <cladisch@googlemail.com>,
Linux-MM <linux-mm@kvack.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 2/2] mm: compaction: Minimise the time IRQs are disabled while isolating pages for migration
Date: Tue, 1 Mar 2011 00:07:12 +0100 [thread overview]
Message-ID: <20110228230712.GR22700@random.random> (raw)
In-Reply-To: <20110228230131.GB1896@barrios-desktop>
On Tue, Mar 01, 2011 at 08:01:31AM +0900, Minchan Kim wrote:
> I am not sure it's good if we release the lock whenever lru->lock was contended
> unconditionally? There are many kinds of lru_lock operations(add to lru,
> del from lru, isolation, reclaim, activation, deactivation and so on).
This is mostly to mirror cond_resched_lock (which actually uses
spin_needbreak but it's ok to have it also when preempt is off). I
doubt it makes a big difference but I tried to mirror
cond_resched_lock.
> Do we really need to release the lock whenever all such operations were contened?
> I think what we need is just spin_is_contended_irqcontext.
> Otherwise, please write down the comment for justifying for it.
What is spin_is_contended_irqcontext?
> This patch is for reducing for irq latency but do we have to check signal
> in irq hold time?
I think it's good idea to check the signal in case the loop is very
long and this is run in direct compaction context.
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next prev parent reply other threads:[~2011-02-28 23:07 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-02-25 20:04 [PATCH 0/2] Reduce the amount of time compaction disables IRQs for V2 Mel Gorman
2011-02-25 20:04 ` Mel Gorman
2011-02-25 20:04 ` [PATCH 1/2] mm: compaction: Minimise the time IRQs are disabled while isolating free pages Mel Gorman
2011-02-25 20:04 ` Mel Gorman
2011-02-25 22:34 ` Johannes Weiner
2011-02-25 22:34 ` Johannes Weiner
2011-02-28 1:55 ` KAMEZAWA Hiroyuki
2011-02-28 1:55 ` KAMEZAWA Hiroyuki
2011-02-28 22:08 ` Minchan Kim
2011-02-28 22:08 ` Minchan Kim
2011-02-25 20:04 ` [PATCH 2/2] mm: compaction: Minimise the time IRQs are disabled while isolating pages for migration Mel Gorman
2011-02-25 20:04 ` Mel Gorman
2011-02-25 22:32 ` Johannes Weiner
2011-02-25 22:32 ` Johannes Weiner
2011-02-26 0:16 ` Andrea Arcangeli
2011-02-26 0:16 ` Andrea Arcangeli
2011-02-28 2:17 ` KAMEZAWA Hiroyuki
2011-02-28 2:17 ` KAMEZAWA Hiroyuki
2011-02-28 5:48 ` Andrea Arcangeli
2011-02-28 5:48 ` Andrea Arcangeli
2011-02-28 5:54 ` KAMEZAWA Hiroyuki
2011-02-28 5:54 ` KAMEZAWA Hiroyuki
2011-02-28 9:28 ` Mel Gorman
2011-02-28 9:28 ` Mel Gorman
2011-02-28 9:42 ` KAMEZAWA Hiroyuki
2011-02-28 9:42 ` KAMEZAWA Hiroyuki
2011-02-28 10:18 ` Mel Gorman
2011-02-28 10:18 ` Mel Gorman
2011-02-28 23:42 ` KAMEZAWA Hiroyuki
2011-02-28 23:42 ` KAMEZAWA Hiroyuki
2011-03-01 4:11 ` Minchan Kim
2011-03-01 4:11 ` Minchan Kim
2011-03-01 4:49 ` KAMEZAWA Hiroyuki
2011-03-01 4:49 ` KAMEZAWA Hiroyuki
2011-02-28 23:01 ` Minchan Kim
2011-02-28 23:01 ` Minchan Kim
2011-02-28 23:07 ` Andrea Arcangeli [this message]
2011-02-28 23:07 ` Andrea Arcangeli
2011-02-28 23:25 ` Minchan Kim
2011-02-28 23:25 ` Minchan Kim
2011-03-01 22:15 ` Andrew Morton
2011-03-01 22:15 ` Andrew Morton
2011-02-25 20:07 ` [PATCH 0/2] Reduce the amount of time compaction disables IRQs for V2 Andrea Arcangeli
2011-02-25 20:07 ` Andrea Arcangeli
-- strict thread matches above, loose matches on Subject: below --
2011-03-01 15:35 [PATCH 2/2] mm: compaction: Minimise the time IRQs are disabled while isolating pages for migration Minchan Kim
2011-03-01 15:35 ` Minchan Kim
2011-03-01 16:19 ` Andrea Arcangeli
2011-03-01 16:19 ` Andrea Arcangeli
2011-03-01 22:22 ` Minchan Kim
2011-03-01 22:22 ` Minchan Kim
2011-03-01 22:34 ` Andrew Morton
2011-03-01 22:34 ` Andrew Morton
2011-03-01 22:57 ` Minchan Kim
2011-03-01 22:57 ` Minchan Kim
2011-02-25 18:00 [PATCH 0/2] Reduce the amount of time compaction disables IRQs for Mel Gorman
2011-02-25 18:00 ` [PATCH 2/2] mm: compaction: Minimise the time IRQs are disabled while isolating pages for migration Mel Gorman
2011-02-25 18:00 ` Mel Gorman
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