Messages in this thread | | | Date | Fri, 11 Dec 2015 10:39:37 +0300 | From | Vladimir Davydov <> | Subject | Re: [PATCH 1/7] mm: memcontrol: charge swap to cgroup2 |
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On Fri, Dec 11, 2015 at 11:48:57AM +0900, Kamezawa Hiroyuki wrote: > On 2015/12/10 20:39, Vladimir Davydov wrote: > > In the legacy hierarchy we charge memsw, which is dubious, because: > > > > - memsw.limit must be >= memory.limit, so it is impossible to limit > > swap usage less than memory usage. Taking into account the fact that > > the primary limiting mechanism in the unified hierarchy is > > memory.high while memory.limit is either left unset or set to a very > > large value, moving memsw.limit knob to the unified hierarchy would > > effectively make it impossible to limit swap usage according to the > > user preference. > > > > - memsw.usage != memory.usage + swap.usage, because a page occupying > > both swap entry and a swap cache page is charged only once to memsw > > counter. As a result, it is possible to effectively eat up to > > memory.limit of memory pages *and* memsw.limit of swap entries, which > > looks unexpected. > > > > That said, we should provide a different swap limiting mechanism for > > cgroup2. > > > > This patch adds mem_cgroup->swap counter, which charges the actual > > number of swap entries used by a cgroup. It is only charged in the > > unified hierarchy, while the legacy hierarchy memsw logic is left > > intact. > > > > The swap usage can be monitored using new memory.swap.current file and > > limited using memory.swap.max. > > > > Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com> > > setting swap.max=0 will work like mlock ?
For anonymous memory - yes.
Thanks, Vladimir
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