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| author | Dave Hansen <dave.hansen@linux.intel.com> | 2021-05-05 04:36:04 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-05-05 21:27:23 +0300 |
| commit | 202e35db5e719ee8af6028183403f475e243f82d (patch) | |
| tree | 2d0c7f0c9d70036a3c5bc39056a51264ac3ac1c0 | |
| parent | b6676de8d7b48724d4cd3a3742c62fa525baa904 (diff) | |
| download | linux-202e35db5e719ee8af6028183403f475e243f82d.tar.xz | |
mm/vmscan: replace implicit RECLAIM_ZONE checks with explicit checks
RECLAIM_ZONE was assumed to be unused because it was never explicitly
used in the kernel. However, there were a number of places where it was
checked implicitly by checking 'node_reclaim_mode' for a zero value.
These zero checks are not great because it is not obvious what a zero
mode *means* in the code. Replace them with a helper which makes it
more obvious: node_reclaim_enabled().
This helper also provides a handy place to explicitly check the
RECLAIM_ZONE bit itself. Check it explicitly there to make it more
obvious where the bit can affect behavior.
This should have no functional impact.
Link: https://lkml.kernel.org/r/20210219172559.BF589C44@viggo.jf.intel.com
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Ben Widawsky <ben.widawsky@intel.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Christoph Lameter <cl@linux.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: "Tobin C. Harding" <tobin@kernel.org>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | include/linux/swap.h | 7 | ||||
| -rw-r--r-- | mm/khugepaged.c | 2 | ||||
| -rw-r--r-- | mm/page_alloc.c | 2 |
3 files changed, 9 insertions, 2 deletions
diff --git a/include/linux/swap.h b/include/linux/swap.h index 4cc6ec3bf0ab..42191da1bdc9 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -12,6 +12,7 @@ #include <linux/fs.h> #include <linux/atomic.h> #include <linux/page-flags.h> +#include <uapi/linux/mempolicy.h> #include <asm/page.h> struct notifier_block; @@ -378,6 +379,12 @@ extern int sysctl_min_slab_ratio; #define node_reclaim_mode 0 #endif +static inline bool node_reclaim_enabled(void) +{ + /* Is any node_reclaim_mode bit set? */ + return node_reclaim_mode & (RECLAIM_ZONE|RECLAIM_WRITE|RECLAIM_UNMAP); +} + extern void check_move_unevictable_pages(struct pagevec *pvec); extern int kswapd_run(int nid); diff --git a/mm/khugepaged.c b/mm/khugepaged.c index a03569eda183..ea74da3232ab 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -809,7 +809,7 @@ static bool khugepaged_scan_abort(int nid) * If node_reclaim_mode is disabled, then no extra effort is made to * allocate memory locally. */ - if (!node_reclaim_mode) + if (!node_reclaim_enabled()) return false; /* If there is a count for this node already, it must be acceptable */ diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 80fa6e0f9ed9..19cdd8a829dc 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -3968,7 +3968,7 @@ retry: if (alloc_flags & ALLOC_NO_WATERMARKS) goto try_this_zone; - if (node_reclaim_mode == 0 || + if (!node_reclaim_enabled() || !zone_allows_reclaim(ac->preferred_zoneref->zone, zone)) continue; |