From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from s3.sipsolutions.net ([5.9.151.49]:38870 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750752AbbIGJyL (ORCPT ); Mon, 7 Sep 2015 05:54:11 -0400 Message-ID: <1441619646.1940.2.camel@sipsolutions.net> (sfid-20150907_115414_364095_4E2B440B) Subject: Re: using dev_coredumpv From: Johannes Berg To: Arend van Spriel Cc: "linux-wireless@vger.kernel.org" Date: Mon, 07 Sep 2015 11:54:06 +0200 In-Reply-To: <55ED5D28.8000309@broadcom.com> (sfid-20150907_114727_883458_63EE9237) References: <55ED5D28.8000309@broadcom.com> (sfid-20150907_114727_883458_63EE9237) Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Mon, 2015-09-07 at 11:47 +0200, Arend van Spriel wrote: > Hi Johannes, > > I am looking at devcoredump subsystem and I was wondering about the > lifetime of the devcd folder. With dev_coredumpm() the description says: > "If a previous one hasn't been read yet, the new coredump is > discarded.". I am wondering what "read" means here. For testing I call > dev_coredumpv() every second, but when I hexdump the data file it does > not create a new devcd folder. That only occurs after 5 minutes. Is that > expected? I suppose "read" should say "discarded by userspace", but I always assumed userspace would read the file and then discard the coredump by writing (anything iirc) to the file. IOW - yes, this is expected, you should write to the data file which makes it (and the folder) disappear and allows creating a new one. johannes