From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Shi Subject: Re: [Resend PATCH 2/6] mm/memcg: remove useless check on page->mem_cgroup Date: Tue, 11 Aug 2020 20:42:28 +0800 Message-ID: References: <1597144232-11370-1-git-send-email-alex.shi@linux.alibaba.com> <1597144232-11370-2-git-send-email-alex.shi@linux.alibaba.com> <20200811113008.GK4793@dhcp22.suse.cz> Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <20200811113008.GK4793-2MMpYkNvuYDjFM9bn6wA6Q@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="iso-8859-1" To: Michal Hocko Cc: akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, Johannes Weiner , Vladimir Davydov , cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org =D4=DA 2020/8/11 =CF=C2=CE=E77:30, Michal Hocko =D0=B4=B5=C0: > subject line looks like a left over. It doesn't match the path. Did you > mean > memcg: bail out early from swap accounting when memcg is disabled? It's much better, Thanks for correction! >=20 > Btw. if this patch was first in the series then you wouldn't need to > mention the warnings that would trigger based on your previous patch. > I am fine with both ways but mentioning the warning is usefule. Right. but the patch is very simple, w/o warning message doesn't cuase tro= uble. So, removing the 'and keep WARN_ON monitor' make sense too. Do I need a resend for the commit log change? Thanks a lot! Alex >=20 > On Tue 11-08-20 19:10:28, Alex Shi wrote: >> If we disabled memcg by cgroup_disable=3Dmemory, the swap charges are >> still called. Let's return from the funcs earlier and keep WARN_ON >> monitor. >> >> Signed-off-by: Alex Shi >> Reviewed-by: Roman Gushchin >> Acked-by: Michal Hocko >> Cc: Johannes Weiner >> Cc: Michal Hocko >> Cc: Vladimir Davydov >> Cc: Andrew Morton >> Cc: cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org >> Cc: linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org >> Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org >> --- >> mm/memcontrol.c | 6 ++++++ >> 1 file changed, 6 insertions(+) >> >> diff --git a/mm/memcontrol.c b/mm/memcontrol.c >> index 299382fc55a9..419cf565f40b 100644 >> --- a/mm/memcontrol.c >> +++ b/mm/memcontrol.c >> @@ -7098,6 +7098,9 @@ void mem_cgroup_swapout(struct page *page, swp_ent= ry_t entry) >> VM_BUG_ON_PAGE(PageLRU(page), page); >> VM_BUG_ON_PAGE(page_count(page), page); >> =20 >> + if (mem_cgroup_disabled()) >> + return; >> + >> if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) >> return; >> =20 >> @@ -7163,6 +7166,9 @@ int mem_cgroup_try_charge_swap(struct page *page, = swp_entry_t entry) >> struct mem_cgroup *memcg; >> unsigned short oldid; >> =20 >> + if (mem_cgroup_disabled()) >> + return 0; >> + >> if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) >> return 0; >> =20 >> --=20 >> 1.8.3.1 >=20