Messages in this thread | | | Date | Thu, 22 Sep 2016 14:37:36 +0200 | From | Michal Hocko <> | Subject | Re: [PATCH 3/5] mm/vmalloc.c: correct lazy_max_pages() return value |
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On Thu 22-09-16 09:13:50, zijun_hu wrote: > On 09/22/2016 08:35 AM, David Rientjes wrote: [...] > > The intent is as it is implemented; with your change, lazy_max_pages() is > > potentially increased depending on the number of online cpus. This is > > only a heuristic, changing it would need justification on why the new > > value is better. It is opposite to what the comment says: "to be > > conservative and not introduce a big latency on huge systems, so go with > > a less aggressive log scale." NACK to the patch. > > > my change potentially make lazy_max_pages() decreased not increased, i seems > conform with the comment > > if the number of online CPUs is not power of 2, both have no any difference > otherwise, my change remain power of 2 value, and the original code rounds up > to next power of 2 value, for instance > > my change : (32, 64] -> 64 > 32 -> 32, 64 -> 64 > the original code: [32, 63) -> 64 > 32 -> 64, 64 -> 128
You still completely failed to explain _why_ this is an improvement/fix or why it matters. This all should be in the changelog.
-- Michal Hocko SUSE Labs
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