From owner-freebsd-net@FreeBSD.ORG Wed Feb 9 00:06:40 2011 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 1252C106564A for ; Wed, 9 Feb 2011 00:06:40 +0000 (UTC) (envelope-from fodillemlinkarim@gmail.com) Received: from mail-px0-f182.google.com (mail-px0-f182.google.com [209.85.212.182]) by mx1.freebsd.org (Postfix) with ESMTP id CA74A8FC0C for ; Wed, 9 Feb 2011 00:06:39 +0000 (UTC) Received: by pxi1 with SMTP id 1so1429314pxi.13 for ; Tue, 08 Feb 2011 16:06:39 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:in-reply-to:references:date :message-id:subject:from:to:cc:content-type; bh=8yRWktruUSzbEXO9d+RKngwbTwTKYApx9YPbuiPhxcU=; b=PL9YUm7yaq7Ux7Za8o0qYk4GxoF9qhmytgoy2Ng54+zeztSGSZuF1lFkH61vvgNH32 8vCOOTffKbcUeeFZZ6cH0p341RMuvs6rHhPQFibcxasI28dgx9sSqEU47WuQFh5cEQBo 7c+xFl9jKgBvjcKJ35g8mU9/9vR7saWLsB/qw= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; b=o1xcnlTQzRzRMujrQjWz4cPdFmURi25Wfa0CeJNsl5muNSNRU08XLE/ghMFZIYQ5lf iHADIYMrsRCRwtcJkpqxrvVO2oQea/M4iUMaKops/5PjZPCwMD5Dlev7ilnDXUZdISRi Dv66kI2/CaLiLFQdAbR/8AGhtCShIiN0jJRrA= MIME-Version: 1.0 Received: by 10.142.216.3 with SMTP id o3mr17667724wfg.29.1297209999308; Tue, 08 Feb 2011 16:06:39 -0800 (PST) Received: by 10.142.246.3 with HTTP; Tue, 8 Feb 2011 16:06:39 -0800 (PST) In-Reply-To: References: Date: Tue, 8 Feb 2011 19:06:39 -0500 Message-ID: From: Karim Fodil-Lemelin To: Jack Vogel Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: Pyun YongHyeon , beezarliu , Michael Tuexen , freebsd-net@freebsd.org Subject: Re: igb driver RX (was TX) hangs when out of mbuf clusters X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 09 Feb 2011 00:06:40 -0000 2011/2/8 Jack Vogel > > I have been following this, and thinking about it. I still am working from > a theoretical > standpoint, but based on a patch I got quite a long time back and never > quite groked, > I believe now that I might have a solution. > > The original PR and patch was kern/150516 from Beezar Liu, I was never > quite comfortable > with the code changes, nor convinced that it was a real issue and not a > misunderstanding. > However I think now that this very report might be behind what we are > seeing today. I have > a slightly different approach to solving it, of course it remains to be > seen if it handles it > properly. > > Please try the patch I've attached, I'm open to further correction or > polishing of the > changes. And thanks to Beezar for his original report and changes, this is > not for em, > but if this eliminates the problem its clearly needed in all drivers. > > Jack > > > Hi Jack, Thanks for your help. I tried your patch and it didn't work so I added a couple of printf to see if the added code was getting hit: --- a/freebsd/sys/dev/e1000/if_igb.c --More--(byte 1253)+++ b/freebsd/sys/dev/e1000/if_igb.c @@ -612,7 +612,7 @@ igb_attach(device_t dev) device_get_nameunit(dev)); INIT_DEBUGOUT("igb_attach: end"); - + printf("this driver has a patch from Jack Vogel\n"); return (0); err_late: @@ -4131,6 +4131,7 @@ igb_rxeof(struct igb_queue *que, int count, int *done) struct mbuf *sendmp, *mh, *mp; struct igb_rx_buf *rxbuf; u16 hlen, plen, hdr, vtag; + int commit; bool eop = FALSE; cur = &rxr->rx_base[i]; @@ -4255,10 +4256,23 @@ next_desc: bus_dmamap_sync(rxr->rxdma.dma_tag, rxr->rxdma.dma_map, BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE); + commit = i; /* capture the old index */ + /* Advance our pointers to the next descriptor. */ if (++i == adapter->num_rx_desc) i = 0; /* + ** Sanity test for ring full, if this + ** happens we need to refresh immediately + ** or refresh may deadlock. + */ + if (i == rxr->next_to_refresh) { + igb_refresh_mbufs(rxr, commit); + printf("igb_refresh_mbufs called with commit %d\n", commit); + processed = 0; + } + + /* ** Send to the stack or LRO */ if (sendmp != NULL) { Here is the results: # dmesg | grep Vogel this driver has a patch from Jack Vogel this driver has a patch from Jack Vogel # netstat -m 60453/52707/113160 mbufs in use (current/cache/total) 48416/51584/100000/100000 mbuf clusters in use (current/cache/total/max) 2894/690 mbuf+clusters out of packet secondary zone in use (current/cache) 11946/854/12800/12800 4k (page size) jumbo clusters in use (current/cache/total/max) 0/0/0/6400 9k jumbo clusters in use (current/cache/total/max) 0/0/0/3200 16k jumbo clusters in use (current/cache/total/max) 164834K/119760K/284595K bytes allocated to network (current/cache/total) 0/339/0 requests for mbufs denied (mbufs/clusters/mbuf+clusters) 0/0/0 requests for jumbo clusters denied (4k/9k/16k) 0/4/6656 sfbufs in use (current/peak/max) 0 requests for sfbufs denied 0 requests for sfbufs delayed 0 requests for I/O initiated by sendfile 0 calls to protocol drain routines # dmesg | grep commit At this point RX has hung. Somehow the check (i == rxr->next_to_refresh) is never true in this case. Also, I did read kern/150516 and couldn't wrap my head around the patch for the em driver that Beezar Liu suggested. Regards, Karim.