From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail191.messagelabs.com (mail191.messagelabs.com [216.82.242.19]) by kanga.kvack.org (Postfix) with SMTP id D17A76B01B4 for ; Tue, 23 Mar 2010 15:14:53 -0400 (EDT) Received: by fxm10 with SMTP id 10so1099179fxm.30 for ; Tue, 23 Mar 2010 12:14:51 -0700 (PDT) Subject: Re: [Bugme-new] [Bug 15618] New: 2.6.18->2.6.32->2.6.33 huge regression in performance Mime-Version: 1.0 (Apple Message framework v1077) Content-Type: text/plain; charset=us-ascii From: Anton Starikov In-Reply-To: Date: Tue, 23 Mar 2010 20:14:48 +0100 Content-Transfer-Encoding: quoted-printable Message-Id: <9D040E9A-80F2-468F-A6CD-A4912615CD3F@gmail.com> References: <20100323102208.512c16cc.akpm@linux-foundation.org> <20100323173409.GA24845@elte.hu> Sender: owner-linux-mm@kvack.org To: Linus Torvalds Cc: Ingo Molnar , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, bugzilla-daemon@bugzilla.kernel.org, bugme-daemon@bugzilla.kernel.org, Peter Zijlstra List-ID: On Mar 23, 2010, at 6:45 PM, Linus Torvalds wrote: >=20 >=20 > On Tue, 23 Mar 2010, Ingo Molnar wrote: >>=20 >> It shows a very brutal amount of page fault invoked mmap_sem spinning=20= >> overhead. >=20 > Isn't this already fixed? It's the same old "x86-64 rwsemaphores are = using=20 > the shit-for-brains generic version" thing, and it's fixed by >=20 > 1838ef1 x86-64, rwsem: 64-bit xadd rwsem implementation > 5d0b723 x86: clean up rwsem type system > 59c33fa x86-32: clean up rwsem inline asm statements >=20 > NOTE! None of those are in 2.6.33 - they were merged afterwards. But = they=20 > are in 2.6.34-rc1 (and obviously current -git). So Anton would have to=20= > compile his own kernel to test his load. Applied mentioned patches. Things didn't improve too much. before: prog: Total exploration time 9.880 real 60.620 user 76.970 sys after: prog: Total exploration time 9.020 real 59.430 user 66.190 sys perf report: 38.58% prog [kernel] = [k] _spin_lock_irqsave 37.42% prog ./prog = [.] DBSLLlookup_ret 6.22% prog ./prog = [.] SuperFastHash 3.65% prog /lib64/libc-2.11.1.so = [.] __GI_memcpy 2.09% prog ./anderson.6.dve2C = [.] get_successors 1.75% prog [kernel] = [k] clear_page_c 1.73% prog ./prog = [.] index_next_dfs 0.71% prog [kernel] = [k] handle_mm_fault 0.38% prog ./prog = [.] cb_hook 0.33% prog ./prog = [.] get_local 0.32% prog [kernel] = [k] page_fault Anton. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org