On Thu, Feb 02, 2012 at 07:08:44PM +0800, Sha Zhengju wrote: > On 02/02/2012 06:54 PM, Sha Zhengju wrote: > >On 02/02/2012 06:14 PM, Kirill A. Shutemov wrote: > >>On Thu, Feb 02, 2012 at 05:45:19PM +0800, Sha Zhengju wrote: > >>>From: Sha Zhengju<handai.szj@xxxxxxxxxx> > >>> > >>>Index current_threshold may point to threshold that just equal to > >>>usage after __mem_cgroup_threshold is triggerd. > >>I don't see it. Could you describe conditions? > >> > >It is because of the following code path in __mem_cgroup_threshold: > >{ > > ... > > i = t->current_threshold; > > > > for (; i >= 0 && unlikely(t->entries[i].threshold > usage); i--) > > eventfd_signal(t->entries[i].eventfd, 1); > > i++; > > > > for (; i < t->size && unlikely(t->entries[i].threshold <= > >usage); i++) > > eventfd_signal(t->entries[i].eventfd, 1); > > > > t->current_threshold = i - 1; > > ... > >} > > > >For example: > >now: > > threshold array: 3 5 7 9 (usage = 6) > > ^ > > index > > > >next turn: > > threshold array: 3 5 7 9 (usage = 7) > > ^ > > index > > > >after registering a new event(threshold = 10): > > threshold array: 3 5 7 9 10 (usage = 7) > > ^ > > index > Err.. Sorry for showing inaccurate index position... (may because of > the mail format) > > now: > threshold array: 3 [5] 7 9 (usage = 6, index = 5) > > next turn: > threshold array: 3 5 [7] 9 (usage = 7, index = 7) > > after registering a new event(threshold = 10): > threshold array: 3 [5] 7 9 10 (usage = 7, index = 5) Good catch! Thank you. Reviewed-by: Kirill A. Shutemov <kirill@xxxxxxxxxxxxx> -- Kirill A. Shutemov -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html