From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f70.google.com (mail-wm0-f70.google.com [74.125.82.70]) by kanga.kvack.org (Postfix) with ESMTP id 298226B0069 for ; Fri, 13 Jan 2017 07:15:40 -0500 (EST) Received: by mail-wm0-f70.google.com with SMTP id l2so15422974wml.5 for ; Fri, 13 Jan 2017 04:15:40 -0800 (PST) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id b9si11023833wrd.48.2017.01.13.04.15.38 for (version=TLS1 cipher=AES128-SHA bits=128/128); Fri, 13 Jan 2017 04:15:38 -0800 (PST) Date: Fri, 13 Jan 2017 13:15:36 +0100 From: Petr Mladek Subject: Re: [PATCH] mm/page_alloc: Wait for oom_lock before retrying. Message-ID: <20170113121536.GK14894@pathway.suse.cz> References: <201612221927.BGE30207.OSFJMFLFOHQtOV@I-love.SAKURA.ne.jp> <20161222134250.GE413@tigerII.localdomain> <201612222301.AFG57832.QOFMSVFOJHLOtF@I-love.SAKURA.ne.jp> <20161222140930.GF413@tigerII.localdomain> <201612261954.FJE69201.OFLVtFJSQFOHMO@I-love.SAKURA.ne.jp> <20161226113407.GA515@tigerII.localdomain> <20170112141844.GA20462@pathway.suse.cz> <20170113022843.GA9360@jagdpanzerIV.localdomain> <20170113110323.GH14894@pathway.suse.cz> <20170113115024.GA16506@jagdpanzerIV.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170113115024.GA16506@jagdpanzerIV.localdomain> Sender: owner-linux-mm@kvack.org List-ID: To: Sergey Senozhatsky Cc: Sergey Senozhatsky , Tetsuo Handa , mhocko@suse.com, linux-mm@kvack.org, Greg Kroah-Hartman , Jiri Slaby , linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org On Fri 2017-01-13 20:50:24, Sergey Senozhatsky wrote: > On (01/13/17 12:03), Petr Mladek wrote: > [..] > > > why can't we? > > > > Because it would newer call cond_resched() in non-preemptive kernel > > with CONFIG_PREEMPT_COUNT disabled. IMHO, we want to call it, > > for example, when we scroll the entire screen from tty_operations. > > > > Or do I miss anything? > > so... basically. it has never called cond_resched() there. right? > why is this suddenly a problem now? But it called cond_resched() when the very same code was called from tty operations under console_lock() that forced console_may_schedule = 1; It will never call cond_resched() from the tty operations when CONFIG_PREEMPT_COUNT is disabled and we try to detect the preemption automatically. Best Regards, Petr -- 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