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* Support variable-sized huge pages
@ 2013-01-31  8:23 Ric Mason
  2013-01-31  8:57 ` Jianguo Wu
  2013-01-31 10:52 ` Andi Kleen
  0 siblings, 2 replies; 7+ messages in thread
From: Ric Mason @ 2013-01-31  8:23 UTC (permalink / raw)
  To: linux-mm; +Cc: Andi Kleen, Hillf Danton

Hi all,

It seems that Andi's "Support more pagesizes for
MAP_HUGETLB/SHM_HUGETLB" patch has already merged. According to the
patch, x86 will support 2MB and 1GB huge pages. But I just see 
hugepages-2048kB under /sys/kernel/mm/hugepages/ on my x86_32 PAE desktop.
Where is 1GB huge pages?

Regards,
Ric  

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^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: Support variable-sized huge pages
  2013-01-31  8:23 Support variable-sized huge pages Ric Mason
@ 2013-01-31  8:57 ` Jianguo Wu
  2013-01-31 10:52 ` Andi Kleen
  1 sibling, 0 replies; 7+ messages in thread
From: Jianguo Wu @ 2013-01-31  8:57 UTC (permalink / raw)
  To: Ric Mason; +Cc: linux-mm, Andi Kleen, Hillf Danton

On 2013/1/31 16:23, Ric Mason wrote:

> Hi all,
> 
> It seems that Andi's "Support more pagesizes for
> MAP_HUGETLB/SHM_HUGETLB" patch has already merged. According to the
> patch, x86 will support 2MB and 1GB huge pages. But I just see 
> hugepages-2048kB under /sys/kernel/mm/hugepages/ on my x86_32 PAE desktop.
> Where is 1GB huge pages?

Hi Ric,
By default only has 2M huge pages, you can specify "hugepagesz=1G hugepages=xx" in boot option,
then you can see: /sys/kernel/mm/hugepages/hugepages-1048576kB.

Thanks,
Jianguo Wu

> 
> Regards,
> Ric  
> 
> --
> To unsubscribe, send a message with 'unsubscribe linux-mm' in
> the body to majordomo@kvack.org.  For more info on Linux MM,
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> 
> 



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^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: Support variable-sized huge pages
  2013-01-31  8:23 Support variable-sized huge pages Ric Mason
  2013-01-31  8:57 ` Jianguo Wu
@ 2013-01-31 10:52 ` Andi Kleen
  2013-02-05  5:48   ` Ric Mason
  2013-02-24  7:00   ` Ric Mason
  1 sibling, 2 replies; 7+ messages in thread
From: Andi Kleen @ 2013-01-31 10:52 UTC (permalink / raw)
  To: Ric Mason; +Cc: linux-mm, Andi Kleen, Hillf Danton

On Thu, Jan 31, 2013 at 02:23:10AM -0600, Ric Mason wrote:
> Hi all,
> 
> It seems that Andi's "Support more pagesizes for
> MAP_HUGETLB/SHM_HUGETLB" patch has already merged. According to the
> patch, x86 will support 2MB and 1GB huge pages. But I just see 
> hugepages-2048kB under /sys/kernel/mm/hugepages/ on my x86_32 PAE desktop.
> Where is 1GB huge pages?

1GB pages are only supported under 64bit kernels, and also
only if you allocate them explicitely with boot options.

-Andi
-- 
ak@linux.intel.com -- Speaking for myself only.

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^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: Support variable-sized huge pages
  2013-01-31 10:52 ` Andi Kleen
@ 2013-02-05  5:48   ` Ric Mason
  2013-02-05  9:51     ` Michal Hocko
  2013-02-05 14:08     ` Andi Kleen
  2013-02-24  7:00   ` Ric Mason
  1 sibling, 2 replies; 7+ messages in thread
From: Ric Mason @ 2013-02-05  5:48 UTC (permalink / raw)
  To: Andi Kleen; +Cc: linux-mm, Hillf Danton

Hi Andi,
On Thu, 2013-01-31 at 11:52 +0100, Andi Kleen wrote:
> On Thu, Jan 31, 2013 at 02:23:10AM -0600, Ric Mason wrote:
> > Hi all,
> > 
> > It seems that Andi's "Support more pagesizes for
> > MAP_HUGETLB/SHM_HUGETLB" patch has already merged. According to the
> > patch, x86 will support 2MB and 1GB huge pages. But I just see 
> > hugepages-2048kB under /sys/kernel/mm/hugepages/ on my x86_32 PAE desktop.
> > Where is 1GB huge pages?
> 
> 1GB pages are only supported under 64bit kernels, and also
> only if you allocate them explicitely with boot options.

I am curious about how can buddy system alloc 1GB huge pages? the most
order buddy system supports is 10. Could you explain to me? 

> 
> -Andi


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^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: Support variable-sized huge pages
  2013-02-05  5:48   ` Ric Mason
@ 2013-02-05  9:51     ` Michal Hocko
  2013-02-05 14:08     ` Andi Kleen
  1 sibling, 0 replies; 7+ messages in thread
From: Michal Hocko @ 2013-02-05  9:51 UTC (permalink / raw)
  To: Ric Mason; +Cc: Andi Kleen, linux-mm, Hillf Danton

On Mon 04-02-13 23:48:46, Ric Mason wrote:
> Hi Andi,
> On Thu, 2013-01-31 at 11:52 +0100, Andi Kleen wrote:
> > On Thu, Jan 31, 2013 at 02:23:10AM -0600, Ric Mason wrote:
> > > Hi all,
> > > 
> > > It seems that Andi's "Support more pagesizes for
> > > MAP_HUGETLB/SHM_HUGETLB" patch has already merged. According to the
> > > patch, x86 will support 2MB and 1GB huge pages. But I just see 
> > > hugepages-2048kB under /sys/kernel/mm/hugepages/ on my x86_32 PAE desktop.
> > > Where is 1GB huge pages?
> > 
> > 1GB pages are only supported under 64bit kernels, and also
> > only if you allocate them explicitely with boot options.
> 
> I am curious about how can buddy system alloc 1GB huge pages? the most
> order buddy system supports is 10. Could you explain to me? 

Have a look at setup_hugepagesz & hugetlb_nrpages_setup (in x86 arch code).
A short answer is. Bootmem is used for allocation > MAX_ORDER.
-- 
Michal Hocko
SUSE Labs

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^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: Support variable-sized huge pages
  2013-02-05  5:48   ` Ric Mason
  2013-02-05  9:51     ` Michal Hocko
@ 2013-02-05 14:08     ` Andi Kleen
  1 sibling, 0 replies; 7+ messages in thread
From: Andi Kleen @ 2013-02-05 14:08 UTC (permalink / raw)
  To: Ric Mason; +Cc: Andi Kleen, linux-mm, Hillf Danton

On Mon, Feb 04, 2013 at 11:48:46PM -0600, Ric Mason wrote:
> Hi Andi,
> On Thu, 2013-01-31 at 11:52 +0100, Andi Kleen wrote:
> > On Thu, Jan 31, 2013 at 02:23:10AM -0600, Ric Mason wrote:
> > > Hi all,
> > > 
> > > It seems that Andi's "Support more pagesizes for
> > > MAP_HUGETLB/SHM_HUGETLB" patch has already merged. According to the
> > > patch, x86 will support 2MB and 1GB huge pages. But I just see 
> > > hugepages-2048kB under /sys/kernel/mm/hugepages/ on my x86_32 PAE desktop.
> > > Where is 1GB huge pages?
> > 
> > 1GB pages are only supported under 64bit kernels, and also
> > only if you allocate them explicitely with boot options.
> 
> I am curious about how can buddy system alloc 1GB huge pages? the most
> order buddy system supports is 10. Could you explain to me? 

It can't, that is why you can only allocate them at boot time.

-Andi

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^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: Support variable-sized huge pages
  2013-01-31 10:52 ` Andi Kleen
  2013-02-05  5:48   ` Ric Mason
@ 2013-02-24  7:00   ` Ric Mason
  1 sibling, 0 replies; 7+ messages in thread
From: Ric Mason @ 2013-02-24  7:00 UTC (permalink / raw)
  To: Andi Kleen; +Cc: linux-mm, Hillf Danton

On 01/31/2013 06:52 PM, Andi Kleen wrote:
> On Thu, Jan 31, 2013 at 02:23:10AM -0600, Ric Mason wrote:
>> Hi all,
>>
>> It seems that Andi's "Support more pagesizes for
>> MAP_HUGETLB/SHM_HUGETLB" patch has already merged. According to the
>> patch, x86 will support 2MB and 1GB huge pages. But I just see
>> hugepages-2048kB under /sys/kernel/mm/hugepages/ on my x86_32 PAE desktop.
>> Where is 1GB huge pages?
> 1GB pages are only supported under 64bit kernels, and also
> only if you allocate them explicitely with boot options.

It seem that before your patch, we also can set mutiple hugepagesz, but 
hugetlbfs just mount default size, correct? IIUC, how can different size 
huge pages be used? If set mutiple hugepagesz, which one is default size?

>
> -Andi

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^ permalink raw reply	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2013-02-24  7:00 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2013-01-31  8:23 Support variable-sized huge pages Ric Mason
2013-01-31  8:57 ` Jianguo Wu
2013-01-31 10:52 ` Andi Kleen
2013-02-05  5:48   ` Ric Mason
2013-02-05  9:51     ` Michal Hocko
2013-02-05 14:08     ` Andi Kleen
2013-02-24  7:00   ` Ric Mason

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