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The > caller cannot get between the decision and the collapse. > > Move the collapse_file() call up into collapse_single_pmd(), so the scan > stops at the decision. > > Two things change with it. The writeback retry re-runs collapse_file() > alone instead of rescanning first; collapse_file() repeats the scan's > checks under the page cache lock anyway. And mm_khugepaged_scan_file So the new version is a little faster by saving a file scan? > fires before the collapse, so for an accepted table its status reads > SCAN_SUCCEED; what the collapse made of the table is for > mm_khugepaged_collapse_file to report. > > Preparation for splitting a collapse into a scan under mmap_lock and a > run without it. The file scan has to stop where the anonymous one will. > > Assisted-by: LLM > Signed-off-by: Kiryl Shutsemau (Meta) > --- > mm/khugepaged.c | 21 +++++++++++++-------- > 1 file changed, 13 insertions(+), 8 deletions(-) > LGTM. Reviewed-by: Zi Yan --=20 Best Regards, Yan, Zi