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authorStefan Roesch <shr@devkernel.io>2023-04-17 22:13:41 -0700
committerAndrew Morton <akpm@linux-foundation.org>2023-04-21 14:52:03 -0700
commitd21077fbc2fc987c2e593c34dc3b4d84e546dc9f (patch)
tree1a56ca5e4613bc2a491ddbcb3d62c7064c97f276 /mm
parentd7597f59d1d33e9efbffa7060deb9ee5bd119e62 (diff)
mm: add new KSM process and sysfs knobs
This adds the general_profit KSM sysfs knob and the process profit metric knobs to ksm_stat. 1) expose general_profit metric The documentation mentions a general profit metric, however this metric is not calculated. In addition the formula depends on the size of internal structures, which makes it more difficult for an administrator to make the calculation. Adding the metric for a better user experience. 2) document general_profit sysfs knob 3) calculate ksm process profit metric The ksm documentation mentions the process profit metric and how to calculate it. This adds the calculation of the metric. 4) mm: expose ksm process profit metric in ksm_stat This exposes the ksm process profit metric in /proc/<pid>/ksm_stat. The documentation mentions the formula for the ksm process profit metric, however it does not calculate it. In addition the formula depends on the size of internal structures. So it makes sense to expose it. 5) document new procfs ksm knobs Link: https://lkml.kernel.org/r/20230418051342.1919757-3-shr@devkernel.io Signed-off-by: Stefan Roesch <shr@devkernel.io> Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Rik van Riel <riel@surriel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/ksm.c21
1 files changed, 21 insertions, 0 deletions
diff --git a/mm/ksm.c b/mm/ksm.c
index 35ac6c741572..9e48258985d2 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -3007,6 +3007,14 @@ static void wait_while_offlining(void)
}
#endif /* CONFIG_MEMORY_HOTREMOVE */
+#ifdef CONFIG_PROC_FS
+long ksm_process_profit(struct mm_struct *mm)
+{
+ return mm->ksm_merging_pages * PAGE_SIZE -
+ mm->ksm_rmap_items * sizeof(struct ksm_rmap_item);
+}
+#endif /* CONFIG_PROC_FS */
+
#ifdef CONFIG_SYSFS
/*
* This all compiles without CONFIG_SYSFS, but is a waste of space.
@@ -3271,6 +3279,18 @@ static ssize_t pages_volatile_show(struct kobject *kobj,
}
KSM_ATTR_RO(pages_volatile);
+static ssize_t general_profit_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ long general_profit;
+
+ general_profit = ksm_pages_sharing * PAGE_SIZE -
+ ksm_rmap_items * sizeof(struct ksm_rmap_item);
+
+ return sysfs_emit(buf, "%ld\n", general_profit);
+}
+KSM_ATTR_RO(general_profit);
+
static ssize_t stable_node_dups_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
@@ -3335,6 +3355,7 @@ static struct attribute *ksm_attrs[] = {
&stable_node_dups_attr.attr,
&stable_node_chains_prune_millisecs_attr.attr,
&use_zero_pages_attr.attr,
+ &general_profit_attr.attr,
NULL,
};