Return-path: Received: from s3.sipsolutions.net ([5.9.151.49]:40838 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754696AbdEQNai (ORCPT ); Wed, 17 May 2017 09:30:38 -0400 Message-ID: <1495027835.2442.13.camel@sipsolutions.net> (sfid-20170517_153104_920423_783570B9) Subject: Re: 'iw events' stops receiving events after a while on 4.9 + hacks From: Johannes Berg To: Bastian Bittorf , Ben Greear Cc: netdev , "linux-wireless@vger.kernel.org" Date: Wed, 17 May 2017 15:30:35 +0200 In-Reply-To: <20170517100844.GC2849@medion.lan> (sfid-20170517_120840_185521_D3BC3321) References: <20170517100844.GC2849@medion.lan> (sfid-20170517_120840_185521_D3BC3321) Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Wed, 2017-05-17 at 12:08 +0200, Bastian Bittorf wrote: > * Ben Greear [17.05.2017 11:51]: > > I have been keeping an 'iw events' program running with a perl > > script gathering its > > output and post-processing it.  This has been working for several > > years on 4.7 and earlier > > kernels, but when testing on 4.9 overnight, I notice that 'iw > > events' is not showing any input.  'strace' shows > > that it is waiting on recvmsg.  If I start a second 'iw events' > > then it will get > > wifi events as expected. > > me too, also seen on 4.4 - i'am happy for debug ideas. I've never seen this. Does it happen when it's very long-running? Or when there are lots of events? Perhaps something in the socket buffer accounting is going wrong, so that it's slowly decreasing to 0? johannes