Messages in this thread |  | | Date | Tue, 08 Apr 2008 08:09:57 +0530 | From | Balbir Singh <> | Subject | Re: [-mm] Add an owner to the mm_struct (v8) |
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Andrew Morton wrote: > On Fri, 04 Apr 2008 13:35:44 +0530 > Balbir Singh <balbir@linux.vnet.ibm.com> wrote: > >> 1. Add mm->owner change callbacks using cgroups >> >> ... >> >> +config MM_OWNER >> + bool "Enable ownership of mm structure" >> + help >> + This option enables mm_struct's to have an owner. The advantage >> + of this approach is that it allows for several independent memory >> + based cgroup controllers to co-exist independently without too >> + much space overhead >> + >> + This feature adds fork/exit overhead. So enable this only if >> + you need resource controllers > > Do we really want to offer this option to people? It's rather a low-level > thing and it's likely to cause more confusion than it's worth. Remember > that most kernels get to our users via kernel vendors - to what will they > be setting this config option? >
I suspect that this kernel option will not be explicitly set it. This option will be selected by other config options (memory controller, swap namespace, revoke*)
>> config CGROUP_MEM_RES_CTLR >> bool "Memory Resource Controller for Control Groups" >> depends on CGROUPS && RESOURCE_COUNTERS >> + select MM_OWNER > > Presumably they'll always be setting it to "y" if they are enabling cgroups > at all. > >> --- linux-2.6.25-rc8/kernel/cgroup.c~memory-controller-add-mm-owner 2008-04-03 22:43:27.000000000 +0530 >> +++ linux-2.6.25-rc8-balbir/kernel/cgroup.c 2008-04-03 22:43:27.000000000 +0530 >> @@ -118,6 +118,7 @@ static int root_count; >> * be called. >> */ >> static int need_forkexit_callback; >> +static int need_mm_owner_callback; > > I suppose these should be __read_mostly. >
Yes, good point. I'll send out v9 with this fix.
-- Warm Regards, Balbir Singh Linux Technology Center IBM, ISTL
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