From mboxrd@z Thu Jan 1 00:00:00 1970 From: ebiederm@xmission.com (Eric W. Biederman) Subject: Re: [PATCH 02/11] bnx2: Call dev_kfree_skby_any instead of dev_kfree_skb. Date: Mon, 10 Mar 2014 21:10:26 -0700 Message-ID: <87eh29ml3h.fsf@xmission.com> References: <874n3fow2i.fsf@xmission.com> <20140304.160825.893718566461536483.davem@davemloft.net> <871ty9qvaf.fsf_-_@xmission.com> <87ppltpgme.fsf_-_@xmission.com> <1394509677.21721.4.camel@edumazet-glaptop2.roam.corp.google.com> Mime-Version: 1.0 Content-Type: text/plain Cc: David Miller , netdev@vger.kernel.org, xiyou.wangcong@gmail.com, mpm@selenic.com, satyam.sharma@gmail.com To: Eric Dumazet Return-path: Received: from out02.mta.xmission.com ([166.70.13.232]:47674 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750967AbaCKEKe (ORCPT ); Tue, 11 Mar 2014 00:10:34 -0400 In-Reply-To: <1394509677.21721.4.camel@edumazet-glaptop2.roam.corp.google.com> (Eric Dumazet's message of "Mon, 10 Mar 2014 20:47:57 -0700") Sender: netdev-owner@vger.kernel.org List-ID: Eric Dumazet writes: > On Mon, 2014-03-10 at 20:18 -0700, Eric W. Biederman wrote: >> Replace dev_kfree_skb with dev_kfree_skb_any in functions that can >> be called in hard irq and other contexts. >> >> Signed-off-by: "Eric W. Biederman" >> --- >> drivers/net/ethernet/broadcom/bnx2.c | 10 +++++----- >> 1 files changed, 5 insertions(+), 5 deletions(-) >> >> diff --git a/drivers/net/ethernet/broadcom/bnx2.c b/drivers/net/ethernet/broadcom/bnx2.c >> index ca6b36220d94..c94735de808d 100644 >> --- a/drivers/net/ethernet/broadcom/bnx2.c >> +++ b/drivers/net/ethernet/broadcom/bnx2.c >> @@ -2885,7 +2885,7 @@ bnx2_tx_int(struct bnx2 *bp, struct bnx2_napi *bnapi, int budget) >> sw_cons = BNX2_NEXT_TX_BD(sw_cons); >> >> tx_bytes += skb->len; >> - dev_kfree_skb(skb); >> + dev_kfree_skb_any(skb); > > This looks like a dev_consume_skb_any() candidate ? That seems reasonable. I am focusing on one dimension at a time. > Anyway, why can this be called from hard irq ? netpoll_poll_dev bnx2_poll bnx2_poll_work bnx2_tx_int > I'll stop my review here, it seems either me or you are confused/tired. I did my best to verify the code paths I am changing actually exist. I think I even have a stack backtrace from skb_release_head_state around somewhere. Transmitted packets frequently have dst cache entries, conntrack entries, and destructores which make them actually problematic to free in hard irq context. Eric