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charset=us-ascii Content-Disposition: inline In-Reply-To: <20200303012203.GR29971@bombadil.infradead.org> User-Agent: Mutt/1.12.2 (2019-09-21) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, Mar 02, 2020 at 05:22:03PM -0800, Matthew Wilcox wrote: > On Mon, Mar 02, 2020 at 04:26:38PM -0800, Minchan Kim wrote: > > @@ -1196,6 +1196,7 @@ int __mm_populate(unsigned long start, unsigned long len, int ignore_errors) > > struct vm_area_struct *vma = NULL; > > int locked = 0; > > long ret = 0; > > + bool tried = false; > > How about ... > > int *lockedp = &locked; > > > > > end = start + len; > > > > @@ -1226,14 +1227,18 @@ int __mm_populate(unsigned long start, unsigned long len, int ignore_errors) > > * double checks the vma flags, so that it won't mlock pages > > * if the vma was already munlocked. > > */ > > - ret = populate_vma_page_range(vma, nstart, nend, &locked); > > + ret = populate_vma_page_range(vma, nstart, nend, > > + tried ? NULL : &locked); > > ret = populate_vma_page_range(vma, nstart, nend, lockedp); > > > if (ret < 0) { > > if (ignore_errors) { > > ret = 0; > > continue; /* continue at next VMA */ > > } > > break; > > - } > > + } else if (ret == 0) > > + tried = true; > > + else > > + tried = false; > > } else if (ret == 0) > lockedp = NULL; > > Maybe there's a better name than lockedp. Thanks for the review, Matthew. It changes the behavior from mine in that it never set lockedp as "non-NULL" since it had retried so that we lose fault retrying optimization for successive addresses I understand the code is not pretty there so that hard to follow it but I am not sure the your suggestion makes it better.