Date: Tue, 27 Jan 2015 10:43:25 -0800 From: Randall Stewart <rrs@freebsd.org> To: freebsd-current@freebsd.org Subject: Callout lockups and spin-lock held to long panic.. Message-ID: <8334666F-AE31-4298-A6D7-11453A22DF41@freebsd.org>
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All: I just wanted to send a note to let folks know I have finally dug to the bottom of the crashes that Sean Bruno has been seeing and will = shortly have a fix committed for it. The problem was related to two callout_reset=E2=80=99s being run with = migration happening and that callout was executing (or waiting to execute). The twin callout resets would in the end each remove the entry from the linked list (twice) thus corrupting the linked list. The software code would thus run, holding the CC_lock spinning forever going through the linked list.. causing the crash. I was able to reproduce this in a branch at netflix here so I can prove that the fix I have actually fixes the issue. It will be a couple more days of proving things out, followed by = hopefully getting interested reviewer=E2=80=99s to review the patch.. and then = from there I can commit it to head .. Best wishes R ------------------------------ Randall Stewart 803-317-4952 (cell)
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