+ mm-damon-core-skip-apply-schemes-if-empty.patch added to mm-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: mm/damon/core: skip apply schemes if empty
has been added to the -mm mm-unstable branch.  Its filename is
     mm-damon-core-skip-apply-schemes-if-empty.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-damon-core-skip-apply-schemes-if-empty.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days

------------------------------------------------------
From: Huaisheng Ye <huaisheng.ye@intel.com>
Subject: mm/damon/core: skip apply schemes if empty
Date: Mon, 16 Jan 2023 14:23:47 +0800

Sometimes there is no scheme in damon's context, for example just use damo
record to monitor workload's data access pattern.

If current damon context doesn't have any scheme in the list, kdamond has
no need to iterate over list of all targets and regions but do nothing.

So, skip apply schemes when ctx->schemes is empty.

Link: https://lkml.kernel.org/r/20230116062347.1148553-1-huaisheng.ye@intel.com
Signed-off-by: Huaisheng Ye <huaisheng.ye@intel.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---


--- a/mm/damon/core.c~mm-damon-core-skip-apply-schemes-if-empty
+++ a/mm/damon/core.c
@@ -1269,7 +1269,8 @@ static int kdamond_fn(void *data)
 			if (ctx->callback.after_aggregation &&
 					ctx->callback.after_aggregation(ctx))
 				break;
-			kdamond_apply_schemes(ctx);
+			if (!list_empty(&ctx->schemes))
+				kdamond_apply_schemes(ctx);
 			kdamond_reset_aggregated(ctx);
 			kdamond_split_regions(ctx);
 			if (ctx->ops.reset_aggregated)
_

Patches currently in -mm which might be from huaisheng.ye@intel.com are

mm-damon-core-skip-apply-schemes-if-empty.patch