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But is it really worth it? Most > file-backed page faults are resolved through the ->map_pages() path > which is almost always filemap_map_pages(), which does something > fairly similar to this already. Do you have any performance numbers? > I tried the will-it-scale page_fault3: https://github.com/antonblanchard/will-it-scale/blob/master/tests/page_fault3.c with 96 processes on a test box with 48C/86T. The test result got about 3.75X better with 4.1X less page fault number with this patch. But It's a micro benchmark which shows extreme friendly case to this patch. I didn't see observed performance gain with other workloads. I suppose shared file write operations may not be common operations? Thanks. Regards Yin, Fengwei