Messages in this thread | | | Date | Fri, 13 Sep 2013 16:52:04 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH 8/9] mm: implement split page table lock for PMD level |
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On Fri, Sep 13, 2013 at 05:25:13PM +0300, Kirill A. Shutemov wrote: > Peter Zijlstra wrote: > > On Fri, Sep 13, 2013 at 04:06:15PM +0300, Kirill A. Shutemov wrote: > > > The basic idea is the same as with PTE level: the lock is embedded into > > > struct page of table's page. > > > > > > Split pmd page table lock only makes sense on big machines. > > > Let's say >= 32 CPUs for now. > > > > Why is this? Couldn't I generate the same amount of contention on PMD > > level as I can on PTE level in the THP case? > > Hm. You are right. You just need more memory for that. > Do you want it to be "4" too?
Well, I would drop your patch-1 and use the same config var.
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