Messages in this thread | | | Date | Wed, 26 Feb 2014 09:55:18 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH v2] mm: per-thread vma caching |
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On Wed, Feb 26, 2014 at 09:50:48AM +0100, Peter Zijlstra wrote: > On Tue, Feb 25, 2014 at 10:16:46AM -0800, Davidlohr Bueso wrote: > > +void vmacache_invalidate_all(void) > > +{ > > + struct task_struct *g, *p; > > + > > + rcu_read_lock(); > > + for_each_process_thread(g, p) { > > + /* > > + * Only flush the vmacache pointers as the > > + * mm seqnum is already set and curr's will > > + * be set upon invalidation when the next > > + * lookup is done. > > + */ > > + memset(p->vmacache, 0, sizeof(p->vmacache)); > > + } > > + rcu_read_unlock(); > > +} > > With all the things being said on this particular piece already; I > wanted to add that the iteration there is incomplete; we can clone() > using CLONE_VM without using CLONE_THREAD. > > Its not common, but it can be done. In that case the above iteration > will miss a task that shares the same mm.
Bugger; n/m that. I just spotted that it's yet another way to iterate all tasks in the system.
Of course we need multiple macros to do this :/
Pretty horrifically expensive though.
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