Date: Tue, 9 Jan 2007 02:15:51 -0800
From: Andrew Morton <akpm@osdl.org>
To: vatsa@in.ibm.com
Cc: Oleg Nesterov <oleg@tv-sign.ru>, David Howells <dhowells@redhat.com>,
       Christoph Hellwig <hch@infradead.org>, Ingo Molnar <mingo@elte.hu>,
       Linus Torvalds <torvalds@osdl.org>, linux-kernel@vger.kernel.org,
       Gautham shenoy <ego@in.ibm.com>
Subject: Re: [PATCH] flush_cpu_workqueue: don't flush an empty ->worklist
Message-Id: <20070109021551.b7781c53.akpm@osdl.org>
In-Reply-To: <20070109100925.GA22080@in.ibm.com>
References: <20070106163851.GA13579@in.ibm.com>
	<20070106111117.54bb2307.akpm@osdl.org>
	<20070107110013.GD13579@in.ibm.com>
	<20070107115957.6080aa08.akpm@osdl.org>
	<20070107210139.GA2332@tv-sign.ru>
	<20070108155428.d76f3b73.akpm@osdl.org>
	<20070109050417.GC589@in.ibm.com>
	<20070108212656.ca77a3ba.akpm@osdl.org>
	<20070109093302.GE589@in.ibm.com>
	<20070109015152.d5021254.akpm@osdl.org>
	<20070109100925.GA22080@in.ibm.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 847
Lines: 18

On Tue, 9 Jan 2007 15:39:26 +0530
Srivatsa Vaddagiri <vatsa@in.ibm.com> wrote:

> I just hope the latency of freeze_processes() is tolerable ..

It'll be roughly proportional to the number of processes, I guess: if we
have 100,000 processes (or threads) doing sleep(1000000) then yeah, it'll
take some time to wake them all up and capture them in refrigerator().

But I suspect a suitable fix for any problems which arise there is to
implement gang-offlining and onlining, rather than the present
one-cpu-at-a-time.  That'd be pretty simple to do: we already have sysfs
interfaces which take a cpumask.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/