From mboxrd@z Thu Jan 1 00:00:00 1970 From: KOSAKI Motohiro Subject: Re: [patch 4/6] x86: finish user fault error path with fatal signal Date: Mon, 29 Jul 2013 15:01:00 -0400 Message-ID: <51F6BBEC.5070203@gmail.com> References: <1374791138-15665-1-git-send-email-hannes@cmpxchg.org> <1374791138-15665-5-git-send-email-hannes@cmpxchg.org> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; bh=A0VzFuzOBY+YhBE4PC7IYTtRjmwOGAVbIZ80owndUA0=; b=ues2QlokxMT1GEleZVj0NukE43EZ+fSN29xJarW1k2wi8tTMFy/aFYf1ucIfM+WJFE 39jjgGbyzaKrifTm4EfwGK/EeCJ1ZxBL3ke0d2sjjmT7UoPCkCI8RzNnx4aG166r0g88 XHNBP6Edc84pAZm/XSAsYOgs8nAhGIZ1/uesoWpeFMBUMNJUFnW6L/57nmkM87zf1Dss WLlL+aEd34xAUHmIkTjhqxpjPjN2MuHS8s4vLI0MlRqxR3sosvmeU+SfVzX0Ql/jbvqR PSjidM+3xICmvEDDa7jv2O6wBaM7L/jYU+ueJTbo+XeSfWek8NKsKLlKAwNe845qrTLZ I57g== In-Reply-To: <1374791138-15665-5-git-send-email-hannes@cmpxchg.org> Sender: owner-linux-mm@kvack.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Johannes Weiner Cc: Andrew Morton , Michal Hocko , David Rientjes , KAMEZAWA Hiroyuki , azurIt , linux-mm@kvack.org, cgroups@vger.kernel.org, x86@kernel.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, kosaki.motohiro@gmail.com (7/25/13 6:25 PM), Johannes Weiner wrote: > The x86 fault handler bails in the middle of error handling when the > task has a fatal signal pending. For a subsequent patch this is a > problem in OOM situations because it relies on > pagefault_out_of_memory() being called even when the task has been > killed, to perform proper per-task OOM state unwinding. > > Shortcutting the fault like this is a rather minor optimization that > saves a few instructions in rare cases. Just remove it for > user-triggered faults. > > Use the opportunity to split the fault retry handling from actual > fault errors and add locking documentation that reads suprisingly > similar to ARM's. > > Signed-off-by: Johannes Weiner Acked-by: KOSAKI Motohiro -- 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