The patch titled
mm: swap-token: add a comment for priority aging
has been added to the -mm tree. Its filename is
mm-swap-token-add-a-comment-for-priority-aging.patch
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------------------------------------------------------
Subject: mm: swap-token: add a comment for priority aging
From: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Docuemnt some swap token aging design decisions.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Acked-by: Rik van Riel <riel@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/thrash.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff -puN mm/thrash.c~mm-swap-token-add-a-comment-for-priority-aging mm/thrash.c
--- a/mm/thrash.c~mm-swap-token-add-a-comment-for-priority-aging
+++ a/mm/thrash.c
@@ -67,6 +67,17 @@ void grab_swap_token(struct mm_struct *m
if (!swap_token_mm)
goto replace_token;
+ /*
+ * Usually, we don't need priority aging because long interval faults
+ * makes priority decrease quickly. But there is one exception. If the
+ * token owner task is sleeping, it never make long interval faults.
+ * Thus, we need a priority aging mechanism instead. The requirements
+ * of priority aging are
+ * 1) An aging interval is reasonable enough long. Too short aging
+ * interval makes quick swap token lost and decrease performance.
+ * 2) The swap token owner task have to get priority aging even if
+ * it's under sleep.
+ */
if ((global_faults - last_aging) > TOKEN_AGING_INTERVAL) {
swap_token_mm->token_priority /= 2;
last_aging = global_faults;
_
Patches currently in -mm which might be from kosaki.motohiro@xxxxxxxxxxxxxx are
vmscanmemcg-memcg-aware-swap-token.patch
vmscanmemcg-memcg-aware-swap-token-fix.patch
vmscanmemcg-memcg-aware-swap-token-fix-checkpatch-fixes.patch
vmscan-implement-swap-token-trace.patch
vmscan-implement-swap-token-priority-aging.patch
memcg-add-documentation-for-the-memorynumastat-api.patch
memcg-add-documentation-for-the-memorynumastat-api-fix.patch
mm-increase-reclaim_distance-to-30.patch
slab-use-numa_no_node.patch
mm-swap-token-fix-dead-link.patch
mm-swap-token-makes-global-variables-to-function-local.patch
mm-swap-token-add-a-comment-for-priority-aging.patch
cpusets-randomize-node-rotor-used-in-cpuset_mem_spread_node.patch
cpusets-randomize-node-rotor-used-in-cpuset_mem_spread_node-fix-2.patch
cpusets-randomize-node-rotor-used-in-cpuset_mem_spread_node-cpusets-initialize-spread-rotor-lazily.patch
cpumask-convert-for_each_cpumask-with-for_each_cpu.patch
cpumask-alloc_cpumask_var-use-numa_no_node.patch
cpumask-add-cpumask_var_t-documentation.patch
kexec-remove-kmsg_dump_kexec.patch
kexec-remove-kmsg_dump_kexec-fix.patch
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