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authorSeongJae Park <sj@kernel.org>2022-12-06 02:08:20 +0300
committerAndrew Morton <akpm@linux-foundation.org>2023-01-19 04:12:43 +0300
commit98def236f63c66629fb6b2d4b69cecffc5b46539 (patch)
treef1f37633f51ea4d37fbfec0114667030094f0bad /include/linux/damon.h
parentda34a8484d162585e22ed8c1e4114aa2f60e3567 (diff)
downloadlinux-98def236f63c66629fb6b2d4b69cecffc5b46539.tar.xz
mm/damon/core: implement damos filter
Patch series "implement DAMOS filtering for anon pages and/or specific memory cgroups" DAMOS let users do system operations in a data access pattern oriented way. The data access pattern, which is extracted by DAMON, is somewhat accurate more than what user space could know in many cases. However, in some situation, users could know something more than the kernel about the pattern or some special requirements for some types of memory or processes. For example, some users would have slow swap devices and knows latency-ciritical processes and therefore want to use DAMON-based proactive reclamation (DAMON_RECLAIM) for only non-anonymous pages of non-latency-critical processes. For such restriction, users could exclude the memory regions from the initial monitoring regions and use non-dynamic monitoring regions update monitoring operations set including fvaddr and paddr. They could also adjust the DAMOS target access pattern. For dynamically changing memory layout and access pattern, those would be not enough. To help the case, add an interface, namely DAMOS filters, which can be used to avoid the DAMOS actions be applied to specific types of memory, to DAMON kernel API (damon.h). At the moment, it supports filtering anonymous pages and/or specific memory cgroups in or out for each DAMOS scheme. This patchset adds the support for all DAMOS actions that 'paddr' monitoring operations set supports ('pageout', 'lru_prio', and 'lru_deprio'), and the functionality is exposed via DAMON kernel API (damon.h) the DAMON sysfs interface (/sys/kernel/mm/damon/admins/), and DAMON_RECLAIM module parameters. Patches Sequence ---------------- First patch implements DAMOS filter interface to DAMON kernel API. Second patch makes the physical address space monitoring operations set to support the filters from all supporting DAMOS actions. Third patch adds anonymous pages filter support to DAMON_RECLAIM, and the fourth patch documents the DAMON_RECLAIM's new feature. Fifth to seventh patches implement DAMON sysfs files for support of the filters, and eighth patch connects the file to use DAMOS filters feature. Ninth patch adds simple self test cases for DAMOS filters of the sysfs interface. Finally, following two patches (tenth and eleventh) document the new features and interfaces. This patch (of 11): DAMOS lets users do system operation in a data access pattern oriented way. The data access pattern, which is extracted by DAMON, is somewhat accurate more than what user space could know in many cases. However, in some situation, users could know something more than the kernel about the pattern or some special requirements for some types of memory or processes. For example, some users would have slow swap devices and knows latency-ciritical processes and therefore want to use DAMON-based proactive reclamation (DAMON_RECLAIM) for only non-anonymous pages of non-latency-critical processes. For such restriction, users could exclude the memory regions from the initial monitoring regions and use non-dynamic monitoring regions update monitoring operations set including fvaddr and paddr. They could also adjust the DAMOS target access pattern. For dynamically changing memory layout and access pattern, those would be not enough. To help the case, add an interface, namely DAMOS filters, which can be used to avoid the DAMOS actions be applied to specific types of memory, to DAMON kernel API (damon.h). At the moment, it supports filtering anonymous pages and/or specific memory cgroups in or out for each DAMOS scheme. Note that this commit adds only the interface to the DAMON kernel API. The impelmentation should be made in the monitoring operations sets, and following commits will add that. Link: https://lkml.kernel.org/r/20221205230830.144349-1-sj@kernel.org Link: https://lkml.kernel.org/r/20221205230830.144349-2-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'include/linux/damon.h')
-rw-r--r--include/linux/damon.h51
1 files changed, 51 insertions, 0 deletions
diff --git a/include/linux/damon.h b/include/linux/damon.h
index ad15a5b88e3a..7907918ad2e0 100644
--- a/include/linux/damon.h
+++ b/include/linux/damon.h
@@ -8,6 +8,7 @@
#ifndef _DAMON_H_
#define _DAMON_H_
+#include <linux/memcontrol.h>
#include <linux/mutex.h>
#include <linux/time64.h>
#include <linux/types.h>
@@ -216,6 +217,39 @@ struct damos_stat {
};
/**
+ * enum damos_filter_type - Type of memory for &struct damos_filter
+ * @DAMOS_FILTER_TYPE_ANON: Anonymous pages.
+ * @DAMOS_FILTER_TYPE_MEMCG: Specific memcg's pages.
+ * @NR_DAMOS_FILTER_TYPES: Number of filter types.
+ */
+enum damos_filter_type {
+ DAMOS_FILTER_TYPE_ANON,
+ DAMOS_FILTER_TYPE_MEMCG,
+ NR_DAMOS_FILTER_TYPES,
+};
+
+/**
+ * struct damos_filter - DAMOS action target memory filter.
+ * @type: Type of the page.
+ * @matching: If the matching page should filtered out or in.
+ * @memcg_id: Memcg id of the question if @type is DAMOS_FILTER_MEMCG.
+ * @list: List head for siblings.
+ *
+ * Before applying the &damos->action to a memory region, DAMOS checks if each
+ * page of the region matches to this and avoid applying the action if so.
+ * Note that the check support is up to &struct damon_operations
+ * implementation.
+ */
+struct damos_filter {
+ enum damos_filter_type type;
+ bool matching;
+ union {
+ unsigned short memcg_id;
+ };
+ struct list_head list;
+};
+
+/**
* struct damos_access_pattern - Target access pattern of the given scheme.
* @min_sz_region: Minimum size of target regions.
* @max_sz_region: Maximum size of target regions.
@@ -239,6 +273,7 @@ struct damos_access_pattern {
* @action: &damo_action to be applied to the target regions.
* @quota: Control the aggressiveness of this scheme.
* @wmarks: Watermarks for automated (in)activation of this scheme.
+ * @filters: Additional set of &struct damos_filter for &action.
* @stat: Statistics of this scheme.
* @list: List head for siblings.
*
@@ -254,6 +289,10 @@ struct damos_access_pattern {
* If all schemes that registered to a &struct damon_ctx are inactive, DAMON
* stops monitoring and just repeatedly checks the watermarks.
*
+ * Before applying the &action to a memory region, &struct damon_operations
+ * implementation could check pages of the region and skip &action to respect
+ * &filters
+ *
* After applying the &action to each region, &stat_count and &stat_sz is
* updated to reflect the number of regions and total size of regions that the
* &action is applied.
@@ -263,6 +302,7 @@ struct damos {
enum damos_action action;
struct damos_quota quota;
struct damos_watermarks wmarks;
+ struct list_head filters;
struct damos_stat stat;
struct list_head list;
};
@@ -516,6 +556,12 @@ static inline unsigned long damon_sz_region(struct damon_region *r)
#define damon_for_each_scheme_safe(s, next, ctx) \
list_for_each_entry_safe(s, next, &(ctx)->schemes, list)
+#define damos_for_each_filter(f, scheme) \
+ list_for_each_entry(f, &(scheme)->filters, list)
+
+#define damos_for_each_filter_safe(f, next, scheme) \
+ list_for_each_entry_safe(f, next, &(scheme)->filters, list)
+
#ifdef CONFIG_DAMON
struct damon_region *damon_new_region(unsigned long start, unsigned long end);
@@ -536,6 +582,11 @@ void damon_destroy_region(struct damon_region *r, struct damon_target *t);
int damon_set_regions(struct damon_target *t, struct damon_addr_range *ranges,
unsigned int nr_ranges);
+struct damos_filter *damos_new_filter(enum damos_filter_type type,
+ bool matching);
+void damos_add_filter(struct damos *s, struct damos_filter *f);
+void damos_destroy_filter(struct damos_filter *f);
+
struct damos *damon_new_scheme(struct damos_access_pattern *pattern,
enum damos_action action, struct damos_quota *quota,
struct damos_watermarks *wmarks);