From owner-svn-src-all@freebsd.org Wed Jan 10 20:32:31 2018 Return-Path: Delivered-To: svn-src-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 0C060E75090 for ; Wed, 10 Jan 2018 20:32:31 +0000 (UTC) (envelope-from wlosh@bsdimp.com) Received: from mail-it0-x22e.google.com (mail-it0-x22e.google.com [IPv6:2607:f8b0:4001:c0b::22e]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id C42566ABF3 for ; Wed, 10 Jan 2018 20:32:30 +0000 (UTC) (envelope-from wlosh@bsdimp.com) Received: by mail-it0-x22e.google.com with SMTP id c16so897149itc.5 for ; Wed, 10 Jan 2018 12:32:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bsdimp-com.20150623.gappssmtp.com; s=20150623; h=mime-version:sender:in-reply-to:references:from:date:message-id :subject:to:cc; bh=QLeTXcaKlmlKRqZoTO2AiryDYTCXIynLq4E2RfEHrV0=; b=UHNqCHgFHegghKqKZgh8rdK5yELtIbNMRUvoGv3vff46hPfjPyIcEaLoe3k9vcOx1M z99k05i+45P9bt04N4z64UxX4gi0L76cipzOqMWKdkgnWyxdJGFIyizw5wUNpxn+Rir7 XqLR3CK36e375p2dyd+DhyC5Fi7rlXxeeSBFx1+E4Iezrnboxj0O61+A0m5deJiVHTJv UtdyNXEFTLUSWjaJVYKZdeCyNHsNfDLIQJGPQvjnmoxAaYokBut3NfdoJchhhFT5hpvs TM4X1yRyOyS1Ci1h6cVQNEZDyWWAia3SzKTXvjHjhh/o/5rqzXa8JAdZHf7UGgcYPkq1 K/Pg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:sender:in-reply-to:references:from :date:message-id:subject:to:cc; bh=QLeTXcaKlmlKRqZoTO2AiryDYTCXIynLq4E2RfEHrV0=; b=uRqE5z3YKF/VAk604Z2YBJOvighfyuq9MFhzFgjDhREedioBe3CoBTkbH5QEz2kvFW X2BO0XEpZjrpKOd1Y6WRPdO19HalBfOoMouyyG5AzY0AdJ9riEKEqQEK5SeIApg/ayh2 eNmjKgby5eo/e8u/A4A+fC8jwxGFRDds+YR7MKsKCf4mMps7l+zSn0nZPy9ctCFkEEWD 8hfTChds+W7yGsVHMgdsOFL1462HdQ+ro0g0BIvrJvc0uUOa+ZmoG6rlM/e6OfW2wXw/ kGm1Xq1Vu1OCR3/xo7xZXEGIrCdzH52sNAqDbFUK/x/ihYW17hjaRHDxxfJqC5FhccLe VYzQ== X-Gm-Message-State: AKwxyte3WtZSTS2vBfJT7CcbJAo+cLxjMjcCW2FT1NFIIwPPe/EUGuRX XX22vK4dIDxrohCVUd9D9BK1ynzX5gY8xub1KCbPew== X-Google-Smtp-Source: ACJfBosnAQpAdj8hJzTtXpodJH5lE6X9mKm59SnDlXPmLY8l86bxOFbgn6auDeUPNARkKaHt35PNxjOJENVk5hBe6Zc= X-Received: by 10.36.1.16 with SMTP id 16mr7357577itk.115.1515616350047; Wed, 10 Jan 2018 12:32:30 -0800 (PST) MIME-Version: 1.0 Sender: wlosh@bsdimp.com Received: by 10.79.160.217 with HTTP; Wed, 10 Jan 2018 12:32:29 -0800 (PST) X-Originating-IP: [2603:300b:6:5100:1052:acc7:f9de:2b6d] In-Reply-To: <20180110202442.GC78524@raichu> References: <201712190413.vBJ4DMY9090982@repo.freebsd.org> <20180110202442.GC78524@raichu> From: Warner Losh Date: Wed, 10 Jan 2018 13:32:29 -0700 X-Google-Sender-Auth: agO5VnT3ukwNwwvE3W1CcyLzM5w Message-ID: Subject: Re: svn commit: r326964 - head/sys/cam To: Mark Johnston Cc: Warner Losh , src-committers , svn-src-all@freebsd.org, svn-src-head@freebsd.org Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.25 X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 10 Jan 2018 20:32:31 -0000 On Wed, Jan 10, 2018 at 1:24 PM, Mark Johnston wrote: > On Tue, Dec 19, 2017 at 04:13:22AM +0000, Warner Losh wrote: > > Author: imp > > Date: Tue Dec 19 04:13:22 2017 > > New Revision: 326964 > > URL: https://svnweb.freebsd.org/changeset/base/326964 > > > > Log: > > When doing a dump, the scheduler is normally not running, so this > > changed worked to capture dumps for me. However, the test for > > SCHEDULER_STOPPED() isn't right. We can also call the dump routine > > from ddb, in which case the scheduler is still running. This leads to > > an assertion panic that we're sleeping when we shouldn't. Instead, use > > the proper test for dumping or not. This brings us in line with other > > places that do special things while we're doing polled I/O like this. > > > > Noticed by: pho@ > > Differential Revision: https://reviews.freebsd.org/D13531 > > > > Modified: > > head/sys/cam/cam_periph.c > > > > Modified: head/sys/cam/cam_periph.c > > ============================================================ > ================== > > --- head/sys/cam/cam_periph.c Tue Dec 19 04:06:07 2017 (r326963) > > +++ head/sys/cam/cam_periph.c Tue Dec 19 04:13:22 2017 (r326964) > > @@ -38,6 +38,7 @@ __FBSDID("$FreeBSD$"); > > #include > > #include > > #include > > +#include > > #include > > #include > > #include > > @@ -1158,7 +1159,7 @@ cam_periph_runccb(union ccb *ccb, > > struct bintime *starttime; > > struct bintime ltime; > > int error; > > - bool sched_stopped; > > + bool must_poll; > > struct mtx *periph_mtx; > > struct cam_periph *periph; > > uint32_t timeout = 1; > > @@ -1182,7 +1183,13 @@ cam_periph_runccb(union ccb *ccb, > > devstat_start_transaction(ds, starttime); > > } > > > > - sched_stopped = SCHEDULER_STOPPED(); > > + /* > > + * We must poll the I/O while we're dumping. The scheduler is > normally > > + * stopped for dumping, except when we call doadump from ddb. > While the > > + * scheduler is running in this case, we still need to poll the > I/O to > > + * avoid sleeping waiting for the ccb to complete. > > + */ > > + must_poll = dumping; > > Hmm, unfortunately this introduces a new problem: after a panic we call > adashutdown() as part of the shutdown_post_sync event. This occurs > before we call doadump(), so dumping == 0 and we don't poll for the > spindown command's completion. But since we've panicked, the scheduler > is stopped, and so we just hang. > So "dumping || SCHEDULER_STOPPED()" then is needed? Warner