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authorLinus Torvalds <torvalds@linux-foundation.org>2022-01-15 20:37:06 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2022-01-15 20:37:06 +0200
commitf56caedaf94f9ced5dbfcdb0060a3e788d2078af (patch)
treee213532d1b3d32f9f0e81948f3b23804baff287d /include/linux/sched
parenta33f5c380c4bd3fa5278d690421b72052456d9fe (diff)
parent76fd0285b447991267e838842c0be7395eb454bb (diff)
Merge branch 'akpm' (patches from Andrew)
Merge misc updates from Andrew Morton: "146 patches. Subsystems affected by this patch series: kthread, ia64, scripts, ntfs, squashfs, ocfs2, vfs, and mm (slab-generic, slab, kmemleak, dax, kasan, debug, pagecache, gup, shmem, frontswap, memremap, memcg, selftests, pagemap, dma, vmalloc, memory-failure, hugetlb, userfaultfd, vmscan, mempolicy, oom-kill, hugetlbfs, migration, thp, ksm, page-poison, percpu, rmap, zswap, zram, cleanups, hmm, and damon)" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (146 commits) mm/damon: hide kernel pointer from tracepoint event mm/damon/vaddr: hide kernel pointer from damon_va_three_regions() failure log mm/damon/vaddr: use pr_debug() for damon_va_three_regions() failure logging mm/damon/dbgfs: remove an unnecessary variable mm/damon: move the implementation of damon_insert_region to damon.h mm/damon: add access checking for hugetlb pages Docs/admin-guide/mm/damon/usage: update for schemes statistics mm/damon/dbgfs: support all DAMOS stats Docs/admin-guide/mm/damon/reclaim: document statistics parameters mm/damon/reclaim: provide reclamation statistics mm/damon/schemes: account how many times quota limit has exceeded mm/damon/schemes: account scheme actions that successfully applied mm/damon: remove a mistakenly added comment for a future feature Docs/admin-guide/mm/damon/usage: update for kdamond_pid and (mk|rm)_contexts Docs/admin-guide/mm/damon/usage: mention tracepoint at the beginning Docs/admin-guide/mm/damon/usage: remove redundant information Docs/admin-guide/mm/damon/usage: update for scheme quotas and watermarks mm/damon: convert macro functions to static inline functions mm/damon: modify damon_rand() macro to static inline function mm/damon: move damon_rand() definition into damon.h ...
Diffstat (limited to 'include/linux/sched')
-rw-r--r--include/linux/sched/mm.h26
1 files changed, 26 insertions, 0 deletions
diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h
index aca874d33fe6..aa5f09ca5bcf 100644
--- a/include/linux/sched/mm.h
+++ b/include/linux/sched/mm.h
@@ -214,6 +214,32 @@ static inline void fs_reclaim_acquire(gfp_t gfp_mask) { }
static inline void fs_reclaim_release(gfp_t gfp_mask) { }
#endif
+/* Any memory-allocation retry loop should use
+ * memalloc_retry_wait(), and pass the flags for the most
+ * constrained allocation attempt that might have failed.
+ * This provides useful documentation of where loops are,
+ * and a central place to fine tune the waiting as the MM
+ * implementation changes.
+ */
+static inline void memalloc_retry_wait(gfp_t gfp_flags)
+{
+ /* We use io_schedule_timeout because waiting for memory
+ * typically included waiting for dirty pages to be
+ * written out, which requires IO.
+ */
+ __set_current_state(TASK_UNINTERRUPTIBLE);
+ gfp_flags = current_gfp_context(gfp_flags);
+ if (gfpflags_allow_blocking(gfp_flags) &&
+ !(gfp_flags & __GFP_NORETRY))
+ /* Probably waited already, no need for much more */
+ io_schedule_timeout(1);
+ else
+ /* Probably didn't wait, and has now released a lock,
+ * so now is a good time to wait
+ */
+ io_schedule_timeout(HZ/50);
+}
+
/**
* might_alloc - Mark possible allocation sites
* @gfp_mask: gfp_t flags that would be used to allocate