From owner-freebsd-stable@FreeBSD.ORG Wed Nov 14 00:52:50 2007 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id E954316A41A for ; Wed, 14 Nov 2007 00:52:49 +0000 (UTC) (envelope-from kip.macy@gmail.com) Received: from nf-out-0910.google.com (nf-out-0910.google.com [64.233.182.190]) by mx1.freebsd.org (Postfix) with ESMTP id 6414C13C455 for ; Wed, 14 Nov 2007 00:52:49 +0000 (UTC) (envelope-from kip.macy@gmail.com) Received: by nf-out-0910.google.com with SMTP id b2so7043nfb for ; Tue, 13 Nov 2007 16:52:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=beta; h=domainkey-signature:received:received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; bh=ERRZh6CHNydSdI/rw9sKcXeTkPd4eGgVj0RxI4qfDso=; b=aHIHUMp1NIGj3iB/Ok5CNiUMdkIANB1h5U0sdaGiraYLZop6mu4Rx7g+au1Ork6t2j+Lf4IRCPa2lcNCkXvBOzCCEPd3IqPkwmTbbqw2ec63FxEgpLhbLyx3EJ2o6uaNvFvjpQT+4wXfstu6tYuRhVi8WTJ1vCXtDJYZ2VQPIhU= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=pXG6fShCzRNEv+d/gOAQ0DYsLF/cZy6Y8o4lQauI/MFgN6zOatcdEi6rQQds2bd5jcCiGcI25YfaI17HAVTpmhNMM1F9IFGqT6U9BvJ2vDGaheuzuA/wA/xDCHJeWSglF+2EAvfznPqEt3jh6PN7XzVBroKb8KOgS2p+4RIYfXU= Received: by 10.142.165.9 with SMTP id n9mr1482891wfe.1195001563978; Tue, 13 Nov 2007 16:52:43 -0800 (PST) Received: by 10.142.230.18 with HTTP; Tue, 13 Nov 2007 16:52:43 -0800 (PST) Message-ID: Date: Tue, 13 Nov 2007 16:52:43 -0800 From: "Kip Macy" To: "Kris Kennaway" In-Reply-To: <473A4620.8010909@FreeBSD.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <0ECA0F43-497A-4823-8731-D517889D5822@khera.org> <91893E44-B766-4B31-9DA7-62F5EC0CCD45@khera.org> <473A4620.8010909@FreeBSD.org> Cc: Vivek Khera , FreeBSD Stable List Subject: Re: reboot after panic: vm_page_unwire: invalid wire count: 0 X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 14 Nov 2007 00:52:50 -0000 Various calls that downgrade permissions or virtually copy a pmap in pmap.c now remove PG_W (and did not 6 months ago). This may be the cause of the regression. It would probably be better (and faster) if the pages were "held" instead of wired. -Kip On Nov 13, 2007 4:49 PM, Kris Kennaway wrote: > Kip Macy wrote: > > Unfortunately, ZERO_COPY_SOCKETs have long been a known source of > > problems. I think also, when a page is copied as part of COW the new > > page is unwired (see pmap_copy et al.), this could lead to > > socow_iodone unwiring after send a page that was not wired. An added > > issue is that parts of the VM assume that COW and wired are mutually > > exclusive which the socow code violates. > > > > At some point in the near future I may be adding support for doing > > zero copy send without COW for blocking sockets. The one down side of > > this approach is that if you have multiple threads in your process it > > widens the window during which they can stomp on data that you're > > sending. Nonetheless, this would be a bug in the application code. > > More complicated would be zero-copy non-COW send on non-blocking > > sockets as it would require an extension to kevent for completion > > notification. > > > > In the meantime, your best bet is to disable ZERO_COPY_SOCKETS. > > There is a chance this was a recent regression, previously in 7.0 they > were believed to work. > > Kris > > > > > > > > -Kip > > > > > > > > On Nov 13, 2007 1:59 PM, Vivek Khera wrote: > >> On Nov 13, 2007, at 4:50 PM, Vlad GALU wrote: > >> > >>>> vmio = 1 > >>>> offset = Unhandled dwarf expression opcode 0x93 > >>>> (kgdb) > >>>> > >>> Do you happen to have ZERO_COPY_SOCKETS in your kernel config? > >>> > >>> > >> Yes, I do. Are they known to be bad under certain loads or just in > >> general. I don't have this issue with any other web server running > >> the same kernel config but those are amd64 boxes mostly. > >> > >> > >> _______________________________________________ > >> freebsd-stable@freebsd.org mailing list > >> http://lists.freebsd.org/mailman/listinfo/freebsd-stable > >> To unsubscribe, send any mail to "freebsd-stable-unsubscribe@freebsd.org" > >> > > _______________________________________________ > > freebsd-stable@freebsd.org mailing list > > http://lists.freebsd.org/mailman/listinfo/freebsd-stable > > To unsubscribe, send any mail to "freebsd-stable-unsubscribe@freebsd.org" > > > > > >