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Yixuan Cao
57eb60c04d
The -f option is to filter out the information of blocks whose memory has not been released, I noticed some blocks should not be filtered out. Commit9cc7e96aa8("mm/page_owner: record timestamp and pid") records the allocation timestamp (ts_nsec) of all pages. Commit866b485262("mm/page_owner: record the timestamp of all pages during free") records the free timestamp (free_ts_nsec) of all pages. When the page is allocated for the first time, the initial value of free_ts_nsec is 0, and the corresponding time will be obtained when the page is released. But during reallocation the free_ts_nsec will not reset to 0 again. In particular, when page migration occurs, these two timestamps will be the same. Now page_owner_sort removes all text blocks whose free_ts_nsec is not 0 when using -f option. However, this way can only select pages allocated for the first time. If a freed page is reallocated, free_ts_nsec will be less than ts_nsec; if page migration occurs, the two timestamps will be equal. These cases should be considered as pages are not released. So I fix the function is_need() to keep text blocks that meet the above two conditions when using -f option. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Yixuan Cao <[email protected]> Cc: Chongxi Zhao <[email protected]> Cc: Jiajian Ye <[email protected]> Cc: Yuhong Feng <[email protected]> Cc: Liam Mark <[email protected]> Cc: Georgi Djakov <[email protected]> Cc: Vlastimil Babka <[email protected]> Cc: Joonsoo Kim <[email protected]> Signed-off-by: Andrew Morton <[email protected]>