Messages in this thread | | | Date | Wed, 07 Nov 2018 11:49:44 +0530 | From | Arun KS <> | Subject | Re: [PATCH v1 0/4]mm: convert totalram_pages, totalhigh_pages and managed pages to atomic |
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On 2018-11-07 05:52, Andrew Morton wrote: > On Fri, 26 Oct 2018 16:30:58 +0530 Arun KS <arunks@codeaurora.org> > wrote: > >> This series convert totalram_pages, totalhigh_pages and >> zone->managed_pages to atomic variables. > > The whole point appears to be removal of managed_page_count_lock, yes? > > Why? What is the value of this patchset? If "performance" then are > any > measurements available?
Hello Andrew,
https://patchwork.kernel.org/patch/10670787/ In version 2, I have added motivation behind this conversion. Pasting same here,
totalram_pages, zone->managed_pages and totalhigh_pages updates are protected by managed_page_count_lock, but readers never care about it. Convert these variables to atomic to avoid readers potentially seeing a store tear. I don't think we have a performance improvement here.
Regards, Arun
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