Gerald Schaefer fc897c95e9 s390/mm: handle PTE-mapped tail pages in fast gup ...

With the THP refcounting rework it is possible to see THP compound tail
pages mapped with PTEs during a THP split. This needs to be considered
when using page_cache_get_speculative(), which will always fail on tail
pages because ->_count is always zero. commit 7aef4172 "mm: handle
PTE-mapped tail pages in gerneric fast gup implementaiton" fixed it for
the generic fast gup code by using compound_head(page) instead of page,
but not for s390.

This patch is a 1:1 adaption of commit 7aef4172 for the s390 fast gup
code. Without this fix, gup will fall back to the slow path or fail
in the unlikely scenario that we hit a THP under splitting in-between
the page table split and the compound page split.

Cc: stable@vger.kernel.org # v4.5
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

2016-03-17 16:42:14 +01:00

..

cmm.c

s390: convert use of typedef ctl_table to struct ctl_table

2013-10-28 08:36:25 +01:00

dump_pagetables.c

s390: remove 31 bit support

2015-03-25 11:49:33 +01:00

extable.c

s390: fix normalization bug in exception table sorting

2016-01-11 13:02:28 +01:00

extmem.c

s390: Use pr_warn instead of pr_warning

2016-03-07 13:12:04 +01:00

fault.c

s390/mm: split arch/s390/mm/pgtable.c

2016-03-08 15:00:15 +01:00

gmap.c

s390/mm: split arch/s390/mm/pgtable.c

2016-03-08 15:00:15 +01:00

gup.c

s390/mm: handle PTE-mapped tail pages in fast gup

2016-03-17 16:42:14 +01:00

hugetlbpage.c

s390/mm: uninline pmdp_xxx functions from pgtable.h

2016-03-08 15:00:14 +01:00

init.c

s390: add DEBUG_RODATA support

2016-03-17 13:18:25 +01:00

maccess.c

s390/maccess: reduce stnsm instructions

2016-02-17 09:05:04 +01:00

Makefile

s390/mm: split arch/s390/mm/pgtable.c

2016-03-08 15:00:15 +01:00

mem_detect.c

s390/mem_detect: use unsigned longs

2016-01-11 12:27:11 +01:00

mmap.c

s390/mm: use TASK_MAX_SIZE where applicable

2016-01-19 12:14:01 +01:00

page-states.c

s390/cmma: remove "cmma disable" code in case of dump again

2014-05-20 08:58:42 +02:00

pageattr.c

s390/pageattr: do a single TLB flush for change_page_attr

2016-02-23 08:56:17 +01:00

pgalloc.c

s390/mm: split arch/s390/mm/pgtable.c

2016-03-08 15:00:15 +01:00

pgtable.c

s390/mm: split arch/s390/mm/pgtable.c

2016-03-08 15:00:15 +01:00

vmem.c

s390: query dynamic DEBUG_PAGEALLOC setting

2016-03-15 16:55:16 -07:00