Messages in this thread | | | Date | Thu, 11 Aug 2016 11:13:47 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH] x86/irq: do not substract irq_tlb_count from irq_call_count |
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* Aaron Lu <aaron.lu@intel.com> wrote:
> This is found by LKP's cyclic performance regression tracking recently > with the vm-scalability test suite. I have bisected to commit > 0a7ce4b5a632 ("mm/rmap: share the i_mmap_rwsem"). This commit didn't do > anything wrong but revealed the irq_call_count problem. IIUC, the commit > makes rwc->remap_one in rmap_walk_file concurrent with multiple threads. > When remap_one is try_to_unmap_one, then multiple threads could queue > flush tlb to the same CPU but only one IPI will be sent.
Note, for some reason the commit ID you used is wrong, the real one is:
3dec0ba0be6a ("mm/rmap: share the i_mmap_rwsem")
I have fixed this in the changelog.
Thanks,
Ingo
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