]> git.karo-electronics.de Git - linux-beck.git/commit
parisc: mm: don't count preallocated pmds
authorMikulas Patocka <mpatocka@redhat.com>
Wed, 18 Mar 2015 17:42:38 +0000 (13:42 -0400)
committerHelge Deller <deller@gmx.de>
Mon, 23 Mar 2015 11:28:15 +0000 (12:28 +0100)
commit0e0da48dee8dfbcc0df4b8e2ff4efc7a2c89ba6b
tree3a648fc0931decd74a2bbb3daae418e5ddc96d5c
parent47514da3ac20150cdf764466fbc2010c0fca0163
parisc: mm: don't count preallocated pmds

The patch dc6c9a35b66b520cf67e05d8ca60ebecad3b0479 that counts pmds
allocated for a process introduced a bug on 64-bit PA-RISC kernels.

The PA-RISC architecture preallocates one pmd with each pgd. This
preallocated pmd can never be freed - pmd_free does nothing when it is
called with this pmd. When the kernel attempts to free this preallocated
pmd, it decreases the count of allocated pmds. The result is that the
counter underflows and this error is reported.

This patch fixes the bug by artifically incrementing the counter in
pmd_free when the kernel tries to free the preallocated pmd.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Helge Deller <deller@gmx.de>
arch/parisc/include/asm/pgalloc.h