Messages in this thread | | | Date | Tue, 21 Jul 2009 21:17:11 +0530 | From | Balbir Singh <> | Subject | Re: [PATCH] cgroup: fix reverse unlock sequence in cgroup_get_sb |
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* menage@google.com <menage@google.com> [2009-07-21 08:34:51]:
> On Tue, Jul 21, 2009 at 5:01 AM, Balbir Singh<balbir@linux.vnet.ibm.com> wrote: > > > > lock(A) > > lock(B) > > unlock(A) > > unlock(B) > > > > Tomorrow if a unsuspecting programmer does this > > > > lock(A) > > lock(B) > > unlock(A) > > > > code block > > > > unlock(B) > > > > > > What protects code block? lock B? Is that the intention? > > > > An "unsuspecting programmer" shouldn't be adding code to > multi-threaded routines without thoroughly understanding the locking. >
Agreed, but why leave behind places for people to do so. There is the consistency factor as well, see below.
> I guess there's no harm in this patch, but as Li says, it doesn't > really change anything. >
Well all the other places do it right in the same routine.
-- Balbir
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