From owner-freebsd-alpha@FreeBSD.ORG Tue Nov 23 00:16:06 2004 Return-Path: Delivered-To: freebsd-alpha@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 8C28516A4CF; Tue, 23 Nov 2004 00:16:06 +0000 (GMT) Received: from ford.blinkenlights.nl (ford.blinkenlights.nl [213.204.211.2]) by mx1.FreeBSD.org (Postfix) with ESMTP id CEA9743D54; Tue, 23 Nov 2004 00:16:05 +0000 (GMT) (envelope-from sten@blinkenlights.nl) Received: from tea.blinkenlights.nl (tea.blinkenlights.nl [192.168.1.8]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ford.blinkenlights.nl (Postfix) with ESMTP id 5B3933E434; Tue, 23 Nov 2004 01:16:03 +0100 (CET) Received: by tea.blinkenlights.nl (Postfix, from userid 101) id DBB8227E; Tue, 23 Nov 2004 01:16:02 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by tea.blinkenlights.nl (Postfix) with ESMTP id CFBAF192; Tue, 23 Nov 2004 01:16:02 +0100 (CET) Date: Tue, 23 Nov 2004 01:16:02 +0100 (CET) From: Sten Spans To: John Baldwin In-Reply-To: <200411221711.54916.jhb@FreeBSD.org> Message-ID: References: <200411221711.54916.jhb@FreeBSD.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed cc: Robert Watson cc: freebsd-alpha@FreeBSD.org Subject: Re: alpha and em mtu X-BeenThere: freebsd-alpha@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Porting FreeBSD to the Alpha List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 23 Nov 2004 00:16:06 -0000 On Mon, 22 Nov 2004, John Baldwin wrote: > On Monday 22 November 2004 04:15 pm, Sten Spans wrote: >> >> db> trace >> tcp_input() at tcp_input+0x3a4 >> ip_input() at ip_input+0x9fc >> netisr_processqueue() at netisr_processqueue+0xac >> swi_net() at swi_net+0xf0 >> ithread_loop() at ithread_loop+0x1d4 >> fork_exit() at fork_exit+0x100 >> exception_return() at exception_return >> --- root of call graph --- >> >> (gdb) l *tcp_input+0x3a4 >> 0xfffffc00004cd054 is in tcp_input (/usr/src/sys/netinet/tcp_input.c:554). >> 549 >> 550 /* >> 551 * Check that TCP offset makes sense, >> 552 * pull out TCP options and adjust length. >> XXX >> 553 */ >> 554 off = th->th_off << 2; >> 555 if (off < sizeof (struct tcphdr) || off > tlen) { >> 556 tcpstat.tcps_rcvbadoff++; >> 557 goto drop; >> 558 } >> (gdb) l *ip_input+0x9fc >> 0xfffffc00004c355c is in ip_input (/usr/src/sys/netinet/ip_input.c:739). >> 734 /* >> 735 * Switch out to protocol's input routine. >> 736 */ >> 737 ipstat.ips_delivered++; >> 738 >> 739 (*inetsw[ip_protox[ip->ip_p]].pr_input)(m, hlen); >> 740 return; >> 741 bad: >> 742 m_freem(m); >> 743 } >> (gdb) l *netisr_processqueue+0xac >> 0xfffffc00004ad45c is in netisr_processqueue >> (/usr/src/sys/net/netisr.c:233). >> 228 >> 229 for (;;) { >> 230 IF_DEQUEUE(ni->ni_queue, m); >> 231 if (m == NULL) >> 232 break; >> 233 ni->ni_handler(m); >> 234 } >> 235 } > > Hmm, so can you check here to see if the 'm' pointer in this routine is > misaligned? If so, then this may be a driver bug. > --- netisr.c.orig Tue Nov 23 00:21:38 2004 +++ netisr.c Tue Nov 23 00:21:45 2004 @@ -230,6 +230,8 @@ IF_DEQUEUE(ni->ni_queue, m); if (m == NULL) break; + if (((uintptr_t)m & 0x3) != 0) + printf("%s: mbuf %p is misaligned\n", __func__, m); ni->ni_handler(m); } } doesn't seem to print anything, but ... if_em.c 2442 2443 /*if (ifp->if_mtu <= ETHERMTU) { */ 2444 m_adj(mp, ETHER_ALIGN); 2445 /*} */ 2446 does seem to fix the crash, also trashes the performance, but that's another matter. It looks like mbuf alignment is needed, if_bge seems to provide reasonable examples. -- Sten Spans "There is a crack in everything, that's how the light gets in." Leonard Cohen - Anthem