Messages in this thread | | | Date | Tue, 31 May 2022 14:58:21 +0200 | Subject | Re: [PATCH 2/3] mm/swapfile: avoid confusing swap cache statistics | From | David Hildenbrand <> |
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On 31.05.22 04:55, Miaohe Lin wrote: > On 2022/5/31 7:04, Andrew Morton wrote: >> On Fri, 27 May 2022 17:26:25 +0800 Miaohe Lin <linmiaohe@huawei.com> wrote: >> >>> At swapoff time, we're going to swap in the pages continuously. So calling >>> lookup_swap_cache would confuse statistics. We should use find_get_page >>> directly here. >> >> Why is the existing behaviour wrong? swapoff() has to swap stuff in to >> be able to release the swap device. Why do you believe that this >> swapin activity should not be accounted? > > IMHO, statistics, e.g. swap_cache_info.find_success, are used to show the effectiveness > of the swap cache activity. So they should only reflect the memory accessing activity > of the user. I think swapoff can't reflect the effectiveness of the swap cache activity > because it just swaps in pages one by one. Or statistics should reflect all the activity > of the user including swapoff?
I'm wondering who cares and why?
-- Thanks,
David / dhildenb
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