Date: Tue, 4 Aug 2020 23:09:16 +0000 (UTC) From: Mateusz Guzik <mjg@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r363875 - head/sys/ufs/ffs Message-ID: <202008042309.074N9Gao027102@repo.freebsd.org>
next in thread | raw e-mail | index | archive | help
Author: mjg Date: Tue Aug 4 23:09:15 2020 New Revision: 363875 URL: https://svnweb.freebsd.org/changeset/base/363875 Log: ufs: only pass LK_ADAPTIVE if LK_NODDLKTREAT is set This restores the pre-adaptive spinning state for SU which livelocks otherwise. Note this is a bug in SU. Reported by: pho Modified: head/sys/ufs/ffs/ffs_vnops.c Modified: head/sys/ufs/ffs/ffs_vnops.c ============================================================================== --- head/sys/ufs/ffs/ffs_vnops.c Tue Aug 4 23:07:42 2020 (r363874) +++ head/sys/ufs/ffs/ffs_vnops.c Tue Aug 4 23:09:15 2020 (r363875) @@ -445,7 +445,13 @@ ffs_lock(ap) struct lock *lkp; int result; - ap->a_flags |= LK_ADAPTIVE; + /* + * Adaptive spinning mixed with SU leads to trouble. use a giant hammer + * and only use it when LK_NODDLKTREAT is set. Currently this means it + * is only used during path lookup. + */ + if ((ap->a_flags & LK_NODDLKTREAT) != 0) + ap->a_flags |= LK_ADAPTIVE; switch (ap->a_flags & LK_TYPE_MASK) { case LK_SHARED: case LK_UPGRADE: @@ -483,7 +489,11 @@ ffs_lock(ap) } return (result); #else - ap->a_flags |= LK_ADAPTIVE; + /* + * See above for an explanation. + */ + if ((ap->a_flags & LK_NODDLKTREAT) != 0) + ap->a_flags |= LK_ADAPTIVE; return (VOP_LOCK1_APV(&ufs_vnodeops, ap)); #endif }
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?202008042309.074N9Gao027102>