Messages in this thread | | | Date | Mon, 20 Jul 2015 18:23:53 +0200 | From | Oleg Nesterov <> | Subject | Re: [PATCH RFC 0/4] change sb_writers to use percpu_rw_semaphore |
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On 07/18, Dave Chinner wrote: > > On Fri, Jul 17, 2015 at 07:31:17PM +0200, Oleg Nesterov wrote: > > > > Dave, I didn't write this comment. Please look at acquire_freeze_lock(). > > If we can remove this logic - great! but this needs a separate change. > > Oh, I think I know what it was - when we duplicate a transaction for > a rolling commit, we do it before committing the current transaction > is committed. I *think* that used to take a second freeze reference, > which only existed until the first transaction was committed. We do > things a bit differently now - we hold a state flag on the > transaction to indicate it needs to release the freeze reference > when it is freed and we pass it to the new transaction so that the > first transaction commit doesn't release it.
Just fyi, please do not assume I can understand the explanation above ;)
> So, yes, it may well be a stale comment now.
Perhaps. But this needs a separate change. Plus even if we remove this hack, this code has other problems with lockdep.
I'll send the "lockdep" fixes/cleanup today, please review.
Oleg.
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