Messages in this thread | ![/](/images/icornerl.gif) | | Date | Thu, 1 Apr 2010 10:23:10 +0530 | From | Balbir Singh <> | Subject | Re: RFC [Patch] Remove "please try 'cgroup_disable=memory' option if you don't want memory cgroups" printk at boot time. |
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* KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> [2010-04-01 10:48:59]:
> On Wed, 31 Mar 2010 13:57:46 -0400 > Rik van Riel <riel@redhat.com> wrote: > > > On 03/31/2010 11:54 AM, Larry Woodman wrote: > > > On Wed, 2010-03-31 at 11:28 -0400, Larry Woodman wrote: > > >> We are considering removing this printk at boot time from RHEL because > > >> it will confuse customers, encourage them to change the boot parameters > > >> and generate extraneous support calls. Its documented in > > >> Documentation/kernel-parameters.txt anyway. Any thoughts??? > > > > Yeah, that is a strange boot message... > > > > Acked-by: Rik van Riel <riel@redhat.com> > > > please CC linux-mm and maintainers. > > Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> > > It have been there for a year and I think memory usage by page_cgroup > will not surprise linux kernel users, more. > > Assume x86-32. > > RHEL allows amount of memory up to 16G, right? > > without memcg: memmap uses 32bytes * 16G/4k = 128M. > with memcg: memmap+page_cgroup uses (32+20) bytes * 16G/4k = 208M. > > I thought this may cause OOM in ZONE_NORMAL. Then, I added it when I wrote > original patch. This kind of memory eater can cause trouble when it pops > up suddenly. But I think 'one year' can be an excuse. >
I've seen this issue come up on multiple machines, I think the printk is useful. However, we might need to change the panic() to a big fat warning and disable the memcg controller if we fail to allocate memory in page_cgroup_init_flatmem().
-- Three Cheers, Balbir
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