diff options
| author | Huang Ying | 2018-08-17 15:49:41 -0700 |
|---|---|---|
| committer | Linus Torvalds | 2018-08-17 16:20:32 -0700 |
| commit | 14fef28414c365a979311821bbf1018a8290cc0f (patch) | |
| tree | acf988e3dce9ab19c6285a56d8266cf7698b3209 /mm | |
| parent | 2a3cb8baef71e4dad4a6ec17f5f0db9e05f46a01 (diff) | |
mm, swap: make CONFIG_THP_SWAP depend on CONFIG_SWAP
CONFIG_THP_SWAP should depend on CONFIG_SWAP, because it's unreasonable
to optimize swapping for THP (Transparent Huge Page) without basic
swapping support.
In original code, when CONFIG_SWAP=n and CONFIG_THP_SWAP=y,
split_swap_cluster() will not be built because it is in swapfile.c, but
it will be called in huge_memory.c. This doesn't trigger a build error
in practice because the call site is enclosed by PageSwapCache(), which
is defined to be constant 0 when CONFIG_SWAP=n. But this is fragile and
should be fixed.
The comments are fixed too to reflect the latest progress.
Link: http://lkml.kernel.org/r/20180713021228.439-1-ying.huang@intel.com
Fixes: 38d8b4e6bdc8 ("mm, THP, swap: delay splitting THP during swap out")
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Shaohua Li <shli@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Zi Yan <zi.yan@cs.rutgers.edu>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/Kconfig | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/mm/Kconfig b/mm/Kconfig index adfeae4decb4..a550635ea5c3 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -419,10 +419,11 @@ config ARCH_WANTS_THP_SWAP config THP_SWAP def_bool y - depends on TRANSPARENT_HUGEPAGE && ARCH_WANTS_THP_SWAP + depends on TRANSPARENT_HUGEPAGE && ARCH_WANTS_THP_SWAP && SWAP help Swap transparent huge pages in one piece, without splitting. - XXX: For now this only does clustered swap space allocation. + XXX: For now, swap cluster backing transparent huge page + will be split after swapout. For selection by architectures with reasonable THP sizes. |