Date: Wed, 26 Jan 2011 16:54:51 -0500 From: John Baldwin <jhb@freebsd.org> To: Warner Losh <imp@freebsd.org> Cc: svn-src-projects@freebsd.org, src-committers@freebsd.org Subject: Re: svn commit: r217907 - projects/graid/head/sys/geom/raid Message-ID: <201101261654.51397.jhb@freebsd.org> In-Reply-To: <201101262034.p0QKYGkB089319@svn.freebsd.org> References: <201101262034.p0QKYGkB089319@svn.freebsd.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Wednesday, January 26, 2011 3:34:16 pm Warner Losh wrote: > Author: imp > Date: Wed Jan 26 20:34:16 2011 > New Revision: 217907 > URL: http://svn.freebsd.org/changeset/base/217907 > > Log: > Set arg before timeout function pointer to avoid a 1 instruction race. > > Modified: > projects/graid/head/sys/geom/raid/tr_raid1.c > > Modified: projects/graid/head/sys/geom/raid/tr_raid1.c > ============================================================================== > --- projects/graid/head/sys/geom/raid/tr_raid1.c Wed Jan 26 20:29:28 2011 (r217906) > +++ projects/graid/head/sys/geom/raid/tr_raid1.c Wed Jan 26 20:34:16 2011 (r217907) > @@ -259,8 +259,8 @@ g_raid_tr_update_state_raid1(struct g_ra > G_RAID_EVENT_VOLUME); > if (s == G_RAID_VOLUME_S_DEGRADED) { > g_raid_tr_raid1_rebuild_start(vol->v_tr, vol); > - vol->v_timeout = g_raid_tr_raid1_idle_rebuild; > vol->v_to_arg = trs; > + vol->v_timeout = g_raid_tr_raid1_idle_rebuild; > } else { > vol->v_timeout = 0; > vol->v_to_arg = 0; Err, this can't solve anything without a memory barrier given the ability of modern CPUs on at least some architectures to reorder writes. -- John Baldwin
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201101261654.51397.jhb>