From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755390Ab1H2XHG (ORCPT ); Mon, 29 Aug 2011 19:07:06 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:36952 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754103Ab1H2XHD (ORCPT ); Mon, 29 Aug 2011 19:07:03 -0400 Date: Mon, 29 Aug 2011 16:06:37 -0700 From: Andrew Morton To: Konstantin Khlebnikov Cc: Hugh Dickins , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Rik van Riel Subject: Re: [PATCH] mm: fix page-faults detection in swap-token logic Message-Id: <20110829160637.bfc86e63.akpm@linux-foundation.org> In-Reply-To: <20110827083201.21854.56111.stgit@zurg> References: <20110827083201.21854.56111.stgit@zurg> X-Mailer: Sylpheed 3.0.2 (GTK+ 2.20.1; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 27 Aug 2011 12:32:01 +0300 Konstantin Khlebnikov wrote: > After commit v2.6.36-5896-gd065bd8 "mm: retry page fault when blocking on disk transfer" > we usually wait in page-faults without mmap_sem held, so all swap-token logic was broken, > because it based on using rwsem_is_locked(&mm->mmap_sem) as sign of in progress page-faults. If I'm interpreting this correctly, the thrash-handling logic has been effectively disabled for a year and nobody noticed. > This patch adds to mm_struct atomic counter of in progress page-faults for mm with swap-token. We desperately need to delete some code from mm/. This seems like a great candidate. Someone prove me wrong? From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail6.bemta8.messagelabs.com (mail6.bemta8.messagelabs.com [216.82.243.55]) by kanga.kvack.org (Postfix) with ESMTP id 4B468900137 for ; Mon, 29 Aug 2011 19:06:57 -0400 (EDT) Date: Mon, 29 Aug 2011 16:06:37 -0700 From: Andrew Morton Subject: Re: [PATCH] mm: fix page-faults detection in swap-token logic Message-Id: <20110829160637.bfc86e63.akpm@linux-foundation.org> In-Reply-To: <20110827083201.21854.56111.stgit@zurg> References: <20110827083201.21854.56111.stgit@zurg> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Konstantin Khlebnikov Cc: Hugh Dickins , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Rik van Riel On Sat, 27 Aug 2011 12:32:01 +0300 Konstantin Khlebnikov wrote: > After commit v2.6.36-5896-gd065bd8 "mm: retry page fault when blocking on disk transfer" > we usually wait in page-faults without mmap_sem held, so all swap-token logic was broken, > because it based on using rwsem_is_locked(&mm->mmap_sem) as sign of in progress page-faults. If I'm interpreting this correctly, the thrash-handling logic has been effectively disabled for a year and nobody noticed. > This patch adds to mm_struct atomic counter of in progress page-faults for mm with swap-token. We desperately need to delete some code from mm/. This seems like a great candidate. Someone prove me wrong? -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org