Re: [PATCH] mm/hugetlb: fix total hugetlbfs pages count when memory overcommit accouting

[Wanpeng Li <liwanp@linux.vnet.ibm.com>]

On Wed, Mar 13, 2013 at 04:02:03PM +0800, Hillf Danton wrote:
>[cc Andi]
>On Wed, Mar 13, 2013 at 3:08 PM, Wanpeng Li <liwanp@linux.vnet.ibm.com> wrote:
>> After commit 42d7395f ("mm: support more pagesizes for MAP_HUGETLB/SHM_HUGETLB")
>> be merged, kernel permit multiple huge page sizes, and when the system administrator
>> has configured the system to provide huge page pools of different sizes, application
>> can choose the page size used for their allocation. However, just default size of
>> huge page pool is statistical when memory overcommit accouting, the bad is that this
>> will result in innocent processes be killed by oom-killer later. Fix it by statistic
>> all huge page pools of different sizes provided by administrator.
>>

Hi Hillf,

>Can we enrich the output of hugetlb_report_meminfo() ?
>

Yes, I have already thought of this stuff, we can dump multiple huge page
pools information in /proc/meminfo and /sys/devices/system/node/node*/meminfo.
I can do it in another patch, what's your opinion, Andi?

Regards,
Wanpeng Li 

>thanks
>Hillf
>
>> Testcase:
>> boot: hugepagesz=1G hugepages=1
>> before patch:
>> egrep 'CommitLimit' /proc/meminfo
>> CommitLimit:     55434168 kB
>> after patch:
>> egrep 'CommitLimit' /proc/meminfo
>> CommitLimit:     54909880 kB
>>
>> Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
>> ---
>>  mm/hugetlb.c | 7 +++++--
>>  1 file changed, 5 insertions(+), 2 deletions(-)
>>
>> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
>> index cdb64e4..9e25040 100644
>> --- a/mm/hugetlb.c
>> +++ b/mm/hugetlb.c
>> @@ -2124,8 +2124,11 @@ int hugetlb_report_node_meminfo(int nid, char *buf)
>>  /* Return the number pages of memory we physically have, in PAGE_SIZE units. */
>>  unsigned long hugetlb_total_pages(void)
>>  {
>> -       struct hstate *h = &default_hstate;
>> -       return h->nr_huge_pages * pages_per_huge_page(h);
>> +       struct hstate *h;
>> +       unsigned long nr_total_pages = 0;
>> +       for_each_hstate(h)
>> +               nr_total_pages += h->nr_huge_pages * pages_per_huge_page(h);
>> +       return nr_total_pages;
>>  }
>>
>>  static int hugetlb_acct_memory(struct hstate *h, long delta)
>> --
>> 1.7.11.7
>>

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>