From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751630AbdKQRxb (ORCPT ); Fri, 17 Nov 2017 12:53:31 -0500 Received: from mail-wr0-f174.google.com ([209.85.128.174]:33183 "EHLO mail-wr0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750828AbdKQRxZ (ORCPT ); Fri, 17 Nov 2017 12:53:25 -0500 X-Google-Smtp-Source: AGs4zMaCqnC7F7XnnnGR38eMEuHY5k2d/NjnYhWzp1ac6ZXiENkVdORyvebNxqh/5b872Rf7WRyEyjVPasx3lcNIO/E= MIME-Version: 1.0 In-Reply-To: References: <1510609063-3327-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp> <20171117173521.GA21692@infradead.org> From: Shakeel Butt Date: Fri, 17 Nov 2017 09:53:22 -0800 Message-ID: Subject: Re: [PATCH 1/2] mm,vmscan: Kill global shrinker lock. To: Christoph Hellwig Cc: Tetsuo Handa , Minchan Kim , Huang Ying , Mel Gorman , Vladimir Davydov , Michal Hocko , Johannes Weiner , Andrew Morton , Greg Thelen , Linux MM , LKML Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Nov 17, 2017 at 9:41 AM, Shakeel Butt wrote: > On Fri, Nov 17, 2017 at 9:35 AM, Christoph Hellwig wrote: >> On Tue, Nov 14, 2017 at 06:37:42AM +0900, Tetsuo Handa wrote: >>> Since do_shrink_slab() can reschedule, we cannot protect shrinker_list >>> using one RCU section. But using atomic_inc()/atomic_dec() for each >>> do_shrink_slab() call will not impact so much. >> >> But you could use SRCU.. > > I looked into that but was advised to not go through that route due to > SRCU behind the CONFIG_SRCU. However now I see the precedence of > "#ifdef CONFIG_SRCU" in drivers/base/core.c and I think if we can take > that route if even after Minchan's patch the issue persists. Too many 'ifs' in the last sentence. I just wanted to say we can consider SRCU if the issue persists even after Minchan's patch. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f71.google.com (mail-wm0-f71.google.com [74.125.82.71]) by kanga.kvack.org (Postfix) with ESMTP id 9B7E46B0253 for ; Fri, 17 Nov 2017 12:53:25 -0500 (EST) Received: by mail-wm0-f71.google.com with SMTP id q127so2353594wmd.1 for ; Fri, 17 Nov 2017 09:53:25 -0800 (PST) Received: from mail-sor-f41.google.com (mail-sor-f41.google.com. [209.85.220.41]) by mx.google.com with SMTPS id 64sor1872687wrs.78.2017.11.17.09.53.24 for (Google Transport Security); Fri, 17 Nov 2017 09:53:24 -0800 (PST) MIME-Version: 1.0 In-Reply-To: References: <1510609063-3327-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp> <20171117173521.GA21692@infradead.org> From: Shakeel Butt Date: Fri, 17 Nov 2017 09:53:22 -0800 Message-ID: Subject: Re: [PATCH 1/2] mm,vmscan: Kill global shrinker lock. Content-Type: text/plain; charset="UTF-8" Sender: owner-linux-mm@kvack.org List-ID: To: Christoph Hellwig Cc: Tetsuo Handa , Minchan Kim , Huang Ying , Mel Gorman , Vladimir Davydov , Michal Hocko , Johannes Weiner , Andrew Morton , Greg Thelen , Linux MM , LKML On Fri, Nov 17, 2017 at 9:41 AM, Shakeel Butt wrote: > On Fri, Nov 17, 2017 at 9:35 AM, Christoph Hellwig wrote: >> On Tue, Nov 14, 2017 at 06:37:42AM +0900, Tetsuo Handa wrote: >>> Since do_shrink_slab() can reschedule, we cannot protect shrinker_list >>> using one RCU section. But using atomic_inc()/atomic_dec() for each >>> do_shrink_slab() call will not impact so much. >> >> But you could use SRCU.. > > I looked into that but was advised to not go through that route due to > SRCU behind the CONFIG_SRCU. However now I see the precedence of > "#ifdef CONFIG_SRCU" in drivers/base/core.c and I think if we can take > that route if even after Minchan's patch the issue persists. Too many 'ifs' in the last sentence. I just wanted to say we can consider SRCU if the issue persists even after Minchan's patch. -- 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