On Wed, 18 May 2011 11:25:48 -0700 (PDT) Hugh Dickins <hughd@xxxxxxxxxx> wrote: > 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. > Thank you for your explanation. I can agree that we should count PGMAJFLT of memcg where the target mm belongs to. Thanks, Daisuke Nishimura. -- 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>