RE: Linux and huge pages

From: <>
Date: Thu, 24 Jan 2013 10:06:43 -0600
Message-ID: <>

Oh I just realized in Yong's example, it actually lists the page size :)

I'm not on 2.6.29 tho so that entry is not in my smaps. So perhaps my deduction would work on previous kernel versions - not sure.


-----Original Message-----
From: [] On Behalf Of Yong Huang Sent: Thursday, January 24, 2013 9:43 AM To:
Subject: RE: Linux and huge pages

> Unfortunately, if you're looking to directly confirm whether a
> particular memory segment was allocated with hugepages, I know of no
> way to do that.

There's no v$ or x$ table for this info, but /proc/<pid>/smaps has KernelPageSize and MMUPageSize if your kernel is new enough, probably 2.6.29 or newer. For example, the following shows a shared memory segment of about 37GB using 2MB page size of HugePages.

70000000-960000000 rwxs 00000000 00:0c 1179654                           /SYSV00000000 (deleted)
Size:           37486592 kB
Rss:                   0 kB
Pss:                   0 kB
Shared_Clean:          0 kB
Shared_Dirty:          0 kB
Private_Clean:         0 kB
Private_Dirty:         0 kB
Referenced:            0 kB
Anonymous:             0 kB
AnonHugePages:         0 kB
Swap:                  0 kB
KernelPageSize:     2048 kB
MMUPageSize:        2048 kB

Regarding the kernel version, my note says "[when] this patch is in your kernel: That patch may be in kernel 2.6.29 (".

Yong Huang


Received on Thu Jan 24 2013 - 17:06:43 CET

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