The patch titled
Subject: mm: compaction: have compaction_suitable() return bool
has been added to the -mm mm-unstable branch. Its filename is
mm-compaction-have-compaction_suitable-return-bool.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-compaction-have-compaction_suitable-return-bool.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Johannes Weiner <hannes@xxxxxxxxxxx>
Subject: mm: compaction: have compaction_suitable() return bool
Date: Fri, 2 Jun 2023 11:12:04 -0400
Since it only returns COMPACT_CONTINUE or COMPACT_SKIPPED now, a bool
return value simplifies the callsites.
Link: https://lkml.kernel.org/r/20230602151204.GD161817@xxxxxxxxxxx
Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Suggested-by: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/compaction.h | 6 +--
mm/compaction.c | 62 ++++++++++++++++-------------------
mm/vmscan.c | 6 +--
3 files changed, 35 insertions(+), 39 deletions(-)
--- a/include/linux/compaction.h~mm-compaction-have-compaction_suitable-return-bool
+++ a/include/linux/compaction.h
@@ -89,7 +89,7 @@ extern enum compact_result try_to_compac
const struct alloc_context *ac, enum compact_priority prio,
struct page **page);
extern void reset_isolation_suitable(pg_data_t *pgdat);
-extern enum compact_result compaction_suitable(struct zone *zone, int order,
+extern bool compaction_suitable(struct zone *zone, int order,
int highest_zoneidx);
extern void compaction_defer_reset(struct zone *zone, int order,
@@ -107,10 +107,10 @@ static inline void reset_isolation_suita
{
}
-static inline enum compact_result compaction_suitable(struct zone *zone, int order,
+static inline bool compaction_suitable(struct zone *zone, int order,
int highest_zoneidx)
{
- return COMPACT_SKIPPED;
+ return false;
}
static inline void kcompactd_run(int nid)
--- a/mm/compaction.c~mm-compaction-have-compaction_suitable-return-bool
+++ a/mm/compaction.c
@@ -2238,9 +2238,9 @@ static enum compact_result compact_finis
return ret;
}
-static enum compact_result __compaction_suitable(struct zone *zone, int order,
- int highest_zoneidx,
- unsigned long wmark_target)
+static bool __compaction_suitable(struct zone *zone, int order,
+ int highest_zoneidx,
+ unsigned long wmark_target)
{
unsigned long watermark;
/*
@@ -2260,28 +2260,21 @@ static enum compact_result __compaction_
watermark = (order > PAGE_ALLOC_COSTLY_ORDER) ?
low_wmark_pages(zone) : min_wmark_pages(zone);
watermark += compact_gap(order);
- if (!__zone_watermark_ok(zone, 0, watermark, highest_zoneidx,
- ALLOC_CMA, wmark_target))
- return COMPACT_SKIPPED;
-
- return COMPACT_CONTINUE;
+ return __zone_watermark_ok(zone, 0, watermark, highest_zoneidx,
+ ALLOC_CMA, wmark_target);
}
/*
* compaction_suitable: Is this suitable to run compaction on this zone now?
- * Returns
- * COMPACT_SKIPPED - If there are too few free pages for compaction
- * COMPACT_SUCCESS - If the allocation would succeed without compaction
- * COMPACT_CONTINUE - If compaction should run now
*/
enum compact_result compaction_suitable(struct zone *zone, int order,
int highest_zoneidx)
{
- enum compact_result ret;
- int fragindex;
+ enum compact_result compact_result;
+ bool suitable;
- ret = __compaction_suitable(zone, order, highest_zoneidx,
- zone_page_state(zone, NR_FREE_PAGES));
+ suitable = __compaction_suitable(zone, order, highest_zoneidx,
+ zone_page_state(zone, NR_FREE_PAGES));
/*
* fragmentation index determines if allocation failures are due to
* low memory or external fragmentation
@@ -2298,17 +2291,24 @@ enum compact_result compaction_suitable(
* excessive compaction for costly orders, but it should not be at the
* expense of system stability.
*/
- if (ret == COMPACT_CONTINUE && (order > PAGE_ALLOC_COSTLY_ORDER)) {
- fragindex = fragmentation_index(zone, order);
- if (fragindex >= 0 && fragindex <= sysctl_extfrag_threshold)
- ret = COMPACT_NOT_SUITABLE_ZONE;
+ if (suitable) {
+ compact_result = COMPACT_CONTINUE;
+ if (order > PAGE_ALLOC_COSTLY_ORDER) {
+ int fragindex = fragmentation_index(zone, order);
+
+ if (fragindex >= 0 &&
+ fragindex <= sysctl_extfrag_threshold) {
+ suitable = false;
+ compact_result = COMPACT_NOT_SUITABLE_ZONE;
+ }
+ }
+ } else {
+ compact_result = COMPACT_SKIPPED;
}
- trace_mm_compaction_suitable(zone, order, ret);
- if (ret == COMPACT_NOT_SUITABLE_ZONE)
- ret = COMPACT_SKIPPED;
+ trace_mm_compaction_suitable(zone, order, compact_result);
- return ret;
+ return suitable;
}
bool compaction_zonelist_suitable(struct alloc_context *ac, int order,
@@ -2334,7 +2334,7 @@ bool compaction_zonelist_suitable(struct
available = zone_reclaimable_pages(zone) / order;
available += zone_page_state_snapshot(zone, NR_FREE_PAGES);
if (__compaction_suitable(zone, order, ac->highest_zoneidx,
- available) == COMPACT_CONTINUE)
+ available))
return true;
}
@@ -2375,11 +2375,10 @@ compact_zone(struct compact_control *cc,
cc->highest_zoneidx, cc->alloc_flags))
return COMPACT_SUCCESS;
- ret = compaction_suitable(cc->zone, cc->order,
- cc->highest_zoneidx);
/* Compaction is likely to fail */
- if (ret == COMPACT_SKIPPED)
- return ret;
+ if (!compaction_suitable(cc->zone, cc->order,
+ cc->highest_zoneidx))
+ return COMPACT_SKIPPED;
}
/*
@@ -2891,7 +2890,7 @@ static bool kcompactd_node_suitable(pg_d
continue;
if (compaction_suitable(zone, pgdat->kcompactd_max_order,
- highest_zoneidx) == COMPACT_CONTINUE)
+ highest_zoneidx))
return true;
}
@@ -2933,8 +2932,7 @@ static void kcompactd_do_work(pg_data_t
min_wmark_pages(zone), zoneid, 0))
continue;
- if (compaction_suitable(zone, cc.order,
- zoneid) != COMPACT_CONTINUE)
+ if (!compaction_suitable(zone, cc.order, zoneid))
continue;
if (kthread_should_stop())
--- a/mm/vmscan.c~mm-compaction-have-compaction_suitable-return-bool
+++ a/mm/vmscan.c
@@ -6416,8 +6416,7 @@ static inline bool should_continue_recla
sc->reclaim_idx, 0))
return false;
- if (compaction_suitable(zone, sc->order,
- sc->reclaim_idx) == COMPACT_CONTINUE)
+ if (compaction_suitable(zone, sc->order, sc->reclaim_idx))
return false;
}
@@ -6613,8 +6612,7 @@ static inline bool compaction_ready(stru
return true;
/* Compaction cannot yet proceed. Do reclaim. */
- if (compaction_suitable(zone, sc->order,
- sc->reclaim_idx) == COMPACT_SKIPPED)
+ if (!compaction_suitable(zone, sc->order, sc->reclaim_idx))
return false;
/*
_
Patches currently in -mm which might be from hannes@xxxxxxxxxxx are
mm-compaction-remove-compaction-result-helpers.patch
mm-compaction-simplify-should_compact_retry.patch
mm-compaction-refactor-__compaction_suitable.patch
mm-compaction-remove-unnecessary-is_via_compact_memory-checks.patch
mm-compaction-drop-redundant-watermark-check-in-compaction_zonelist_suitable.patch
mm-page_isolation-write-proper-kerneldoc.patch
mm-compaction-avoid-gfp_nofs-abba-deadlock.patch
mm-compaction-have-compaction_suitable-return-bool.patch
