From mboxrd@z Thu Jan 1 00:00:00 1970 From: Or Gerlitz Subject: Re: [PATCH] IB/mlx4: fix post_recv wq overflow check Date: Thu, 07 Jan 2010 11:01:25 +0200 Message-ID: <4B45A2E5.2070301@voltaire.com> References: <4B45913C.10405@Voltaire.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Roland Dreier Cc: linux-rdma , Jack Morgenstein List-Id: linux-rdma@vger.kernel.org Roland Dreier wrote: > Actually I was planning on sending it for 2.6.33, since it's so small and obvious and we're reasonable early in the cycle. Not sure about -stable though -- has this been hit in practice? I agree that it should go into 2.6.33, since its so small there's no reason to wait for 2.6.34. As for the being hit question: note that without there is both bug in the overflow check and creation of extra contention between the post recv and poll send cq flows, for ULPs that have their send cq different from the recv cq, e.g IPoIB, I came a cross this bug when reviewing the mlx4 posting code when during some profiling. I wonder if the overflow check could be removed all together and be left to the ULP (kernel is trusted environment...) is there any risk in doing so? this way the WR posting code will not experience contention with the poll WC code on the CQ lock. Or. -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html