From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [RFC PATCH 1/9] ipvs network name space aware Date: Thu, 21 Oct 2010 10:01:12 +0200 Message-ID: <1287648072.6871.15.camel@edumazet-laptop> References: <201010081316.46690.hans.schillstrom@ericsson.com> <201010201025.20950.hans.schillstrom@ericsson.com> <20101020160205.GB2386@linux.vnet.ibm.com> <201010210945.55252.hans.schillstrom@ericsson.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: "paulmck@linux.vnet.ibm.com" , Daniel Lezcano , "lvs-devel@vger.kernel.org" , "netdev@vger.kernel.org" , "netfilter-devel@vger.kernel.org" , "horms@verge.net.au" , "ja@ssi.bg" , "wensong@linux-vs.org" To: Hans Schillstrom Return-path: In-Reply-To: <201010210945.55252.hans.schillstrom@ericsson.com> Sender: netfilter-devel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Le jeudi 21 octobre 2010 =C3=A0 09:45 +0200, Hans Schillstrom a =C3=A9c= rit : > I do have this (and some debuging) > __rcu_read_lock() > =3D> 0xffffffff8108bcf3 <+0>: push %rbp > 0xffffffff8108bcf4 <+1>: mov %rsp,%rbp > 0xffffffff8108bcf7 <+4>: nopl 0x0(%rax,%rax,1) > 0xffffffff8108bcfc <+9>: mov %gs:0xb540,%rax > 0xffffffff8108bd05 <+18>: mov 0x108(%rax),%edx > 0xffffffff8108bd0b <+24>: inc %edx > 0xffffffff8108bd0d <+26>: mov %edx,0x108(%rax) > 0xffffffff8108bd13 <+32>: leaveq > 0xffffffff8108bd14 <+33>: retq >=20 > which is not that many, actually imprerssing few instructions :-) nopl 0x0(%rax,%rax,1) is a filler because of extra instrumentation in your kernel. Maybe you could find out why your compiler dont use incl 0x108(%rax) instead of mov 0x108(%rax),%edx inc %edx mov %edx,0x108(%rax) So rcu_read_lock() is really _two_ instructions. I agree with Paul with the "few" qualification... :-) -- To unsubscribe from this list: send the line "unsubscribe netfilter-dev= el" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html