Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932259Ab2KVV0Q (ORCPT ); Thu, 22 Nov 2012 16:26:16 -0500 Received: from mail-we0-f174.google.com ([74.125.82.174]:33424 "EHLO mail-we0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755076Ab2KVV0L (ORCPT ); Thu, 22 Nov 2012 16:26:11 -0500 MIME-Version: 1.0 In-Reply-To: <50AE0210.7010301@jan-o-sch.net> References: <50AE0210.7010301@jan-o-sch.net> From: Kay Sievers Date: Thu, 22 Nov 2012 13:29:00 +0100 Message-ID: Subject: Re: /proc/kmsg giving eof on blocking read To: Jan Schmidt Cc: 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 Content-Length: 795 Lines: 16 On Thu, Nov 22, 2012 at 11:44 AM, Jan Schmidt wrote: > I'm currently debugging something in btrfs in good old printk style, generating > around 10MB/min. I'm seeing /proc/kmsg returning eof on a blocking read (and, > side note, syslog-ng won't reopen it, effectively stopping logging kernel > messages silently). Are you sure there is not something else that opens the same file? Even once might be enough to return 0. The too simple locking logic in /proc/kmsg cannot support multiple readers properly, it never did. Kay -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/