From: Christoph Lameter <clameter@engr.sgi.com>
To: Andi Kleen <ak@suse.de>
Cc: Hugh Dickins <hugh@veritas.com>,
Linus Torvalds <torvalds@osdl.org>, Andrew Morton <akpm@osdl.org>,
nickpiggin@yahoo.com.au, linux-mm@kvack.org
Subject: Re: [PATCH] Use deltas to replace atomic inc
Date: Mon, 22 Aug 2005 09:24:57 -0700 (PDT) [thread overview]
Message-ID: <Pine.LNX.4.62.0508220921460.6727@schroedinger.engr.sgi.com> (raw)
In-Reply-To: <20050822154300.GA29976@wotan.suse.de>
On Mon, 22 Aug 2005, Andi Kleen wrote:
> > The page_table_lock is taken using a spin_trylock. Its skipped if
> > contended.
> Hmm - doesn't try lock cause a cache line bounce on the bus too?
> I think it does. That would mean its latency is not much better
> than a real spinlock (assuming it doesn't have to spin)
Trylock does a cmpxchg on ia64 and thus acquires a exclusive cache line.
So yes. But this is only done if there are updates pending. schedule() is
not called that frequently. On bootup I see on average updates of 5-20
pages per mm_counter_catchup.
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next prev parent reply other threads:[~2005-08-22 16:24 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-08-17 22:17 pagefault scalability patches Andrew Morton
2005-08-17 22:19 ` Christoph Lameter
2005-08-17 22:36 ` Linus Torvalds
2005-08-17 22:51 ` Christoph Lameter
2005-08-17 23:01 ` Linus Torvalds
2005-08-17 23:12 ` Christoph Lameter
2005-08-17 23:23 ` Linus Torvalds
2005-08-17 23:31 ` Christoph Lameter
2005-08-17 23:30 ` Andrew Morton
2005-08-17 23:33 ` Christoph Lameter
2005-08-17 23:44 ` Andrew Morton
2005-08-17 23:52 ` Peter Chubb
2005-08-17 23:58 ` Christoph Lameter
2005-08-18 0:47 ` Andrew Morton
2005-08-18 16:09 ` Christoph Lameter
2005-08-22 2:13 ` Benjamin Herrenschmidt
2005-08-18 0:43 ` Andrew Morton
2005-08-18 16:04 ` Christoph Lameter
2005-08-18 20:16 ` Hugh Dickins
2005-08-19 1:22 ` [PATCH] use mm_counter macros for nr_pte since its also under ptl Christoph Lameter
2005-08-19 3:17 ` Andrew Morton
2005-08-19 3:51 ` Christoph Lameter
2005-08-19 1:33 ` pagefault scalability patches Christoph Lameter
2005-08-19 3:53 ` [RFC] Concept for delayed counter updates in mm_struct Christoph Lameter
2005-08-19 4:29 ` Andrew Morton
2005-08-19 4:34 ` Andi Kleen
2005-08-19 4:49 ` Linus Torvalds
2005-08-19 16:06 ` Christoph Lameter
2005-08-20 7:33 ` [PATCH] mm_struct counter deltas in task_struct Christoph Lameter
2005-08-20 7:35 ` [PATCH] Use deltas to replace atomic inc Christoph Lameter
2005-08-20 7:58 ` Andrew Morton
2005-08-22 3:32 ` Christoph Lameter
2005-08-22 3:48 ` Linus Torvalds
2005-08-22 4:06 ` Christoph Lameter
2005-08-22 4:18 ` Linus Torvalds
2005-08-22 13:23 ` Christoph Lameter
2005-08-22 14:22 ` Hugh Dickins
2005-08-22 15:24 ` Christoph Lameter
2005-08-22 15:43 ` Andi Kleen
2005-08-22 16:24 ` Christoph Lameter [this message]
2005-08-22 20:30 ` [PATCH] mm_struct counter deltas V2 Christoph Lameter
2005-08-22 20:31 ` [PATCH] Use deltas to replace atomic inc V2 Christoph Lameter
2005-08-22 2:09 ` pagefault scalability patches Benjamin Herrenschmidt
2005-08-18 2:00 ` Nick Piggin
2005-08-18 8:38 ` Nick Piggin
2005-08-18 16:17 ` Christoph Lameter
2005-08-22 2:04 ` Benjamin Herrenschmidt
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