On Fri, Jul 09, 2021 at 06:28:55PM +0800, Yanfei Xu wrote: > While the nr_populated is non-zero, however the nr_account might be > zero if allocating fails. In this case, not to count event can save > some cycles. > The much more likely path is that nr_account is positive so we avoid a branch in the common case. > And this commit extract the check of "page_array" from a while > statement to avoid unnecessary checks for it. > I'm surprised the compiler does not catch that page_array is invariant for the loop. Did you check if gcc generates different code is page_array is explicitly checked once instead of putting it in the loop? -- Mel Gorman SUSE Labs
