From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Frederic Sowa Subject: Re: [PATCH -next] net: tcp: add mib counters to track zero window transitions Date: Wed, 19 Feb 2014 20:32:13 +0100 Message-ID: <20140219193213.GD1179@order.stressinduktion.org> References: <1392674268-26005-1-git-send-email-fw@strlen.de> <20140219.131708.562226572566677127.davem@davemloft.net> <1392835787.18849.11.camel@edumazet-glaptop2.roam.corp.google.com> <20140219185949.GA1179@order.stressinduktion.org> <20140219191831.GA7119@breakpoint.cc> <20140219193038.GC1179@order.stressinduktion.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 To: Florian Westphal , Eric Dumazet , David Miller , netdev@vger.kernel.org Return-path: Received: from order.stressinduktion.org ([87.106.68.36]:39064 "EHLO order.stressinduktion.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754542AbaBSTcO (ORCPT ); Wed, 19 Feb 2014 14:32:14 -0500 Content-Disposition: inline In-Reply-To: <20140219193038.GC1179@order.stressinduktion.org> Sender: netdev-owner@vger.kernel.org List-ID: Sorry... On Wed, Feb 19, 2014 at 08:30:38PM +0100, Hannes Frederic Sowa wrote: > NET_STATS only use 32 bit counter and thus need not be protected with a > seqlock on 32 bit platforms. As such, it does not matter, but e.g. the IP > counter are prone to deadlocks if used with wrong postfix because of 64 bit > counter thus protected by seqlock. > > A pitty that the _STATS_BH postfixes have the opposite meaning of the bottom s/bottom$/locking/ > _bh postfixes. > > Basically always safe is _STATS and if we are sure we can omit the bh disable > call because we only call the function from bh, we can use _STATS_BH calls. Should read mails again before sending. ;)