From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johannes Berg Subject: Re: [PATCH] skbuff: make skb_put_zero() return void Date: Fri, 16 Jun 2017 00:17:25 +0200 Message-ID: <1497565045.2518.14.camel@sipsolutions.net> References: <20170614201720.21070-1-johannes@sipsolutions.net> <1497472613.18751.67.camel@perches.com> <1497472829.9377.13.camel@sipsolutions.net> <1497475096.18751.76.camel@perches.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit To: Joe Perches , netdev@vger.kernel.org Return-path: Received: from s3.sipsolutions.net ([5.9.151.49]:53942 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751667AbdFOWR1 (ORCPT ); Thu, 15 Jun 2017 18:17:27 -0400 In-Reply-To: <1497475096.18751.76.camel@perches.com> Sender: netdev-owner@vger.kernel.org List-ID: On Wed, 2017-06-14 at 14:18 -0700, Joe Perches wrote: > On Wed, 2017-06-14 at 22:40 +0200, Johannes Berg wrote: > > On Wed, 2017-06-14 at 13:36 -0700, Joe Perches wrote: > > > > > > Given you are adding a lot of these, it might be better > > > to add an exported function that duplicates most of > > > skb_put with a memset at the end. > > > > Yeah, could be done. I'm not sure why you'd want to duplicate it > > rather > > than call it though? To make it about as fast? > > Yeah, that and reduced stack use. > > Dunno how performance sensitive these uses really are > but it seems some might be for slow cpu wireless APs in > both the rx and tx paths. I haven't really checked now, but the wireless (mac80211) ones I saw weren't in the data TX/RX, only for management SKBs which are pretty much a slowpath. Anyway, I guess you know how to propose a patch with this :-) However, I think in that case there should be something like skb_pull_inline, so that the skb_put code here isn't all copied around, but just lives in a single place that gets inlined into skb_put() and skb_put_zero(). johannes