Messages in this thread | | | Date | Tue, 22 Aug 2017 18:22:36 +0900 | From | Byungchul Park <> | Subject | Re: [PATCH v3 1/3] lockdep: Make LOCKDEP_CROSSRELEASE configs all part of PROVE_LOCKING |
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On Tue, Aug 22, 2017 at 11:06:03AM +0200, Peter Zijlstra wrote: > So I did the below little hack, which basically wipes the entire lock > history when we start a work and thereby disregards/looses the > dependency on the work 'lock'. > > It makes my test box able to boot and build a kernel on XFS, so while I > see what you're saying (I think), it doesn't appear to instantly show. > > Should I run xfstests or something to further verify things are OK? Does > that need a scratch partition (I keep forgetting how to run that stuff > :/). > > --- > diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c > index 66011c9f5df3..de91cdce9460 100644 > --- a/kernel/locking/lockdep.c > +++ b/kernel/locking/lockdep.c > @@ -4756,10 +4756,14 @@ void crossrelease_hist_start(enum xhlock_context_t c) > { > struct task_struct *cur = current; > > - if (cur->xhlocks) { > - cur->xhlock_idx_hist[c] = cur->xhlock_idx; > - cur->hist_id_save[c] = cur->hist_id; > - } > + if (!cur->xhlocks) > + return; > + > + if (c == XHLOCK_PROC) > + invalidate_xhlock(&xhlock(cur->xhlock_idx));
We have to detect dependecies if it exists, even in the following case:
oooooooiiiiiiiiiiiiiiiiiii......... |<- range for commit ->|
where o: acquisition outside of each work, i: acquisition inside of each work,
With yours, we can never detect dependecies wrt 'o'.
We have to remove false dependencies if we established them incorrectly.
I will also think it more.
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