From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266527AbUGMVyW (ORCPT ); Tue, 13 Jul 2004 17:54:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266898AbUGMVyW (ORCPT ); Tue, 13 Jul 2004 17:54:22 -0400 Received: from mail020.syd.optusnet.com.au ([211.29.132.131]:16013 "EHLO mail020.syd.optusnet.com.au") by vger.kernel.org with ESMTP id S266527AbUGMVxK (ORCPT ); Tue, 13 Jul 2004 17:53:10 -0400 Message-ID: <40F459AF.1040501@kolivas.org> Date: Wed, 14 Jul 2004 07:52:47 +1000 From: Con Kolivas User-Agent: Mozilla Thunderbird 0.7.1 (X11/20040626) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Andrew Morton Cc: ck@vds.kolivas.org, linux-kernel@vger.kernel.org, wli@holomorphy.com Subject: Re: Preempt Threshold Measurements References: <200407121943.25196.devenyga@mcmaster.ca> <20040713024051.GQ21066@holomorphy.com> <200407122248.50377.devenyga@mcmaster.ca> <20040712210107.1945ac34.akpm@osdl.org> <20040712231406.427caa2a.akpm@osdl.org> In-Reply-To: <20040712231406.427caa2a.akpm@osdl.org> X-Enigmail-Version: 0.84.1.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig61F45D7A991DB24C4B604764" Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig61F45D7A991DB24C4B604764 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Andrew Morton wrote: > This can run under one of two depths of lock_kernel. filemap_fdatawrite() > and filemap_fdatawait() both do cond_resched(), so this is odd. > > Try this: > > --- 25/mm/truncate.c~truncate_inode_pages-latency-fix 2004-07-12 23:12:53.871816320 -0700 > +++ 25-akpm/mm/truncate.c 2004-07-12 23:13:00.993733624 -0700 > @@ -155,6 +155,7 @@ void truncate_inode_pages(struct address > > next = start; > for ( ; ; ) { > + cond_resched(); > if (!pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) { > if (next == start) > break; > _ I had a few of these with this patch. Is it cond_resched'ing twice? Con 2ms non-preemptible critical section violated 1 ms preempt threshold starting at flush_commit_list+0x11d/0x3ee and ending at schedule+0x216/0x841 [] dec_preempt_count+0x14f/0x151 [] schedule+0x216/0x841 [] schedule+0x216/0x841 [] do_IRQ+0x176/0x1eb [] cpu_idle+0x3a/0x3c [] start_kernel+0x19c/0x1e8 [] unknown_bootoption+0x0/0x15e 2ms non-preemptible critical section violated 1 ms preempt threshold starting at do_journal_end+0x539/0xae8 and ending at schedule+0x216/0x841 [] dec_preempt_count+0x14f/0x151 [] schedule+0x216/0x841 [] schedule+0x216/0x841 [] smp_apic_timer_interrupt+0x97/0x166 [] cpu_idle+0x3a/0x3c [] call_console_drivers+0xcd/0xea [] release_console_sem+0xa3/0x101 [] printk+0x13d/0x19c 2ms non-preemptible critical section violated 1 ms preempt threshold starting at flush_async_commits+0x1b/0xf7 and ending at schedule+0x216/0x841 [] dec_preempt_count+0x14f/0x151 [] schedule+0x216/0x841 [] schedule+0x216/0x841 [] load_balance+0x147/0x1ff [] smp_apic_timer_interrupt+0x97/0x166 [] work_resched+0x5/0x16 --------------enig61F45D7A991DB24C4B604764 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFA9FmyZUg7+tp6mRURAiQyAKCUuMIdq4Ezp4d/rTQaSiP1g4OOfACggujA vkb90s7mPett568Gqa+/3Vc= =dlP+ -----END PGP SIGNATURE----- --------------enig61F45D7A991DB24C4B604764--