Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261286AbVANSkm (ORCPT ); Fri, 14 Jan 2005 13:40:42 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261305AbVANSkm (ORCPT ); Fri, 14 Jan 2005 13:40:42 -0500 Received: from omx2-ext.sgi.com ([192.48.171.19]:52934 "EHLO omx2.sgi.com") by vger.kernel.org with ESMTP id S261286AbVANSka (ORCPT ); Fri, 14 Jan 2005 13:40:30 -0500 Message-ID: <002901c4fa68$7266a990$6900a8c0@comcast.net> From: "John Hawkes" To: "Robert Love" Cc: "John McCutchan" , "John Hawkes" , References: <200501132356.j0DNujUY016224@tomahawk.engr.sgi.com> <1105663758.6027.215.camel@localhost> <1105666283.15782.2.camel@vertex> <1105669742.6027.243.camel@localhost> <002301c4fa63$9d9d3b10$6900a8c0@comcast.net> <1105726549.6027.268.camel@localhost> Subject: Re: 2.6.10-mm3 scaling problem with inotify Date: Fri, 14 Jan 2005 10:39:56 -0800 MIME-Version: 1.0 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.00.2919.6600 X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2919.6600 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2171 Lines: 52 From: "Robert Love" > On Fri, 2005-01-14 at 10:05 -0800, John Hawkes wrote: > > > The patch shows a substantial 4x improvement for my specific workload (@64p), > > although I can still envision workloads that will stimulate high spinlock > > contention from spin_lock(&dentry->d_lock). First things first -- let's get > > this fix into the -mm tree. Thanks! > > Glad it worked! > > Does the spin_lock() show up in dnotify's code path? It is getting > called, unconditionally, there, too. No, it doesn't show up (with this workload). Lock contention and cacheline contention can be complex. Contention in one area can alter the timing of other areas and reduce contention. Anyway, with your inotify_dentry_parent_queue_event() patch, the PC sampling for my workload is now (with the lock waits getting rolled up to the callers) for everything above 0.1% is: 12:38pm Samples: 1887402, Mode: pc, load average: 1832.89, 1722.88, 1264.14 COUNT ( % ) ADDR NAME 843466 (44.7) a000000100147ba0 vma_adjust 521940 (27.7) a0000001001131a0 USER 278285 (14.7) a000000100150d20 anon_vma_unlink 26952 ( 1.4) a000000100150ba0 anon_vma_link 26099 ( 1.4) a00000010013c1e0 clear_page_range 16638 ( 0.9) a0000001007473e0 established_get_next 12378 ( 0.7) a00000010044b200 _mcount 12150 ( 0.6) a000000100039d20 ia64_brk 10237 ( 0.5) a00000010013dba0 zap_pte_range 9886 ( 0.5) a00000010044aba0 copy_page 9311 ( 0.5) a00000010013cfe0 copy_pte_range 8239 ( 0.4) a00000010014bcc0 do_munmap 5014 ( 0.3) a0000001001c1340 update_atime 4743 ( 0.3) a00000010044b300 __copy_user 4462 ( 0.2) a0000001004dc360 inotify_dentry_parent_queue_event 4439 ( 0.2) a000000100115020 find_get_page 3602 ( 0.2) a0000001000b0e40 copy_mm 3581 ( 0.2) a0000001000d3d80 del_timer_sync 2951 ( 0.2) a0000001001720e0 vfs_read John Hawkes - 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/