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b=SL1tW23G0jwhJatVTw2kTkI2WNVbC21kHc+RVnXVIoWiU8LTFakU3HLdp8MReg5+eI8/ZC vMlR8u6dPhRWV3JekWFNcqJ29ebKjJTek3admrIl+jL5UPgGHGQYJboWMJXYZpfpI9ahpa Fp3gYbXHwMEdfZzA8xU11hFse6JyzFM= X-Stat-Signature: sr6kfmm8kck67afdtoper535j5jntw7n X-Rspamd-Queue-Id: 32EF38012D Authentication-Results: imf02.hostedemail.com; dkim=pass header.d=Nvidia.com header.s=selector2 header.b=NeugPlrR; spf=pass (imf02.hostedemail.com: domain of jhubbard@nvidia.com designates 40.107.220.65 as permitted sender) smtp.mailfrom=jhubbard@nvidia.com; dmarc=pass (policy=reject) header.from=nvidia.com; arc=pass ("microsoft.com:s=arcselector9901:i=1") X-Rspam-User: X-Rspamd-Server: rspam12 X-HE-Tag: 1659654423-849861 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 8/3/22 20:22, Alistair Popple wrote: > @@ -1970,29 +1968,25 @@ static long check_and_migrate_movable_pages(unsigned long nr_pages, > drain_allow = false; > } > > - if (folio_isolate_lru(folio)) { > - isolation_error_count++; > + if (folio_isolate_lru(folio)) > continue; > - } > + > list_add_tail(&folio->lru, &movable_page_list); > node_stat_mod_folio(folio, > NR_ISOLATED_ANON + folio_is_file_lru(folio), > folio_nr_pages(folio)); > } > > - if (!list_empty(&movable_page_list) || isolation_error_count || > - coherent_pages) > - goto unpin_pages; > - > /* > - * If list is empty, and no isolation errors, means that all pages are > - * in the correct zone. > + * All pages are still pinned and in the correct zone. > */ > - return nr_pages; > + if (list_empty(&movable_page_list) && !coherent_pages) > + return 0; > At this point, a second part of the (rather long) routine begins. If I were refactoring this, I'd split it into a top level routine that calls the two parts: check_and_migrate_movable_pages() collect_migration_candidates() unpin_and_migrate_pages() ...which I think would further help in working with this thing. (I realize that this is additional work. And that it's best done as a separate patch. And it's just a suggestion.) > -unpin_pages: > /* > - * pages[i] might be NULL if any device coherent pages were found. > + * Unpin all pages. If device coherent pages were found > + * migrate_deivce_coherent_page() will have already dropped the pin and "migrate_device_coherent_page()" thanks, -- John Hubbard NVIDIA