On Wed, 18 May 2011, Daisuke Nishimura wrote: > On Tue, 17 May 2011 11:24:40 -0700 (PDT) > Hugh Dickins <hughd@xxxxxxxxxx> wrote: > > > mem_cgroup_count_vm_event() should update the PGMAJFAULT count for the > > target mm, not for current mm (but of course they're usually the same). > > > hmm, why ? > In shmem_getpage(), we charge the page to the memcg where current mm belongs to, (In the case when it's this fault which is creating the page. Just as when filemap_fault() reads in the page, add_to_page_cache will charge it to the current->mm's memcg, yes. Arguably correct.) > so I think counting vm events of the memcg is right. It should be consistent with which task gets the maj_flt++, and it should be consistent with filemap_fault(), and it should be a subset of what's counted by mem_cgroup_count_vm_event(mm, PGFAULT). In each case, those work on target mm rather than current->mm. Hugh -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>