Messages in this thread | | | Date | Mon, 4 Jul 2016 13:30:57 +0900 | From | Byungchul Park <> | Subject | Re: [RFC 08/12] lockdep: Apply crossrelease to PG_locked lock |
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On Fri, Jul 01, 2016 at 02:18:46PM +0300, Kirill A. Shutemov wrote: > On Fri, Jul 01, 2016 at 08:21:21AM +0900, Byungchul Park wrote: > > On Thu, Jun 30, 2016 at 03:04:58PM +0200, Peter Zijlstra wrote: > > > On Mon, Jun 20, 2016 at 01:55:23PM +0900, Byungchul Park wrote: > > > > @@ -215,6 +219,11 @@ struct page { > > > > #ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS > > > > int _last_cpupid; > > > > #endif > > > > + > > > > +#ifdef CONFIG_LOCKDEP_PAGELOCK > > > > + struct lockdep_map map; > > > > + struct cross_lock xlock; > > > > +#endif > > > > } > > > > > > So that's 32+64=96 bytes (CONFIG_LOCK_STAT=n) added to struct page, > > > really!? > > > > Yes... I concerned it at first, but I thought it would be ok since > > CONFIG_LOCKDEP_PAGE is a debug feature. Anyway, I will try to reduce > > the size of struct cross_lock which is only thing I can do to reduce > > it, since we cannot avoid using lockdep_map if we want to make > > lock_page() participate in the lockdep play. > > Please use page_ext instead. With boottime switch to enable. > > This way we can have this compile-time debug option enabled on more > machines without unnecessary runtime overhead.
Thank you for advice.
I also think it's one of good candidates except the fact that it have to depend on page_ext additionally.
> > And, please, CC linux-mm next time. > > -- > Kirill A. Shutemov
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