mm-add-new-ksm-process-and-sysfs-knobs.patch removed from -mm tree
The quilt patch titled
Subject: mm: add new KSM process and sysfs knobs
has been removed from the -mm tree. Its filename was
mm-add-new-ksm-process-and-sysfs-knobs.patch
This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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From: Stefan Roesch <[email protected]>
Subject: mm: add new KSM process and sysfs knobs
Date: Mon, 17 Apr 2023 22:13:41 -0700
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
---
Documentation/ABI/testing/sysfs-kernel-mm-ksm | 8 ++++++ Documentation/admin-guide/mm/ksm.rst | 5 +++ fs/proc/base.c | 3 ++ include/linux/ksm.h | 5 +++ mm/ksm.c | 21 ++++++++++++++++ 5 files changed, 41 insertions(+), 1 deletion(-)
Documentation/ABI/testing/sysfs-kernel-mm-ksm renamed from Documentation/ABI/testing/sysfs-kernel-mm-ksm~mm-add-new-ksm-process-and-sysfs-knobs +8 -0
@@ -51,3 +51,11 @@ Description: Control merging pages acros When it is set to 0 only pages from the same node are merged, otherwise pages from all nodes can be merged together (default). + +What: /sys/kernel/mm/ksm/general_profit +Date: April 2023 +KernelVersion: 6.4 +Contact: Linux memory management mailing list <[email protected]> +Description: Measure how effective KSM is. + general_profit: how effective is KSM. The formula for the + calculation is in Documentation/admin-guide/mm/ksm.rst.
Documentation/admin-guide/mm/ksm.rst renamed from Documentation/admin-guide/mm/ksm.rst~mm-add-new-ksm-process-and-sysfs-knobs +4 -1
@@ -157,6 +157,8 @@ stable_node_chains_prune_millisecs The effectiveness of KSM and MADV_MERGEABLE is shown in ``/sys/kernel/mm/ksm/``: +general_profit + how effective is KSM. The calculation is explained below. pages_shared how many shared pages are being used pages_sharing
@@ -207,7 +209,8 @@ several times, which are unprofitable me ksm_rmap_items * sizeof(rmap_item). where ksm_merging_pages is shown under the directory ``/proc/<pid>/``, - and ksm_rmap_items is shown in ``/proc/<pid>/ksm_stat``. + and ksm_rmap_items is shown in ``/proc/<pid>/ksm_stat``. The process profit + is also shown in ``/proc/<pid>/ksm_stat`` as ksm_process_profit. From the perspective of application, a high ratio of ``ksm_rmap_items`` to ``ksm_merging_pages`` means a bad madvise-applied policy, so developers or
fs/proc/base.c renamed from fs/proc/base.c~mm-add-new-ksm-process-and-sysfs-knobs +3 -0
@@ -96,6 +96,7 @@#include <linux/time_namespace.h> #include <linux/resctrl.h> #include <linux/cn_proc.h> +#include <linux/ksm.h> #include <trace/events/oom.h> #include "internal.h" #include "fd.h"
@@ -3207,6 +3208,8 @@ static int proc_pid_ksm_stat(struct seq_ mm =get_task_mm (task);if (mm) {seq_printf (m,"ksm_rmap_items %lu\n" , mm->ksm_rmap_items); +seq_printf (m,"ksm_merging_pages %lu\n" , mm->ksm_merging_pages); +seq_printf (m,"ksm_process_profit %ld\n" ,ksm_process_profit (mm));mmput (mm); }
include/linux/ksm.h renamed from include/linux/ksm.h~mm-add-new-ksm-process-and-sysfs-knobs +5 -0
@@ -68,6 +68,11 @@ void folio_migrate_ksm(struct folio *newvoid collect_procs_ksm (struct page *page,struct list_head *to_kill,int force_early);#endif + +#ifdef CONFIG_PROC_FS +long ksm_process_profit (struct mm_struct *); +#endif /* CONFIG_PROC_FS */ +#else /* !CONFIG_KSM */ static inline void ksm_add_vma (struct vm_area_struct *vma)
mm/ksm.c renamed from mm/ksm.c~mm-add-new-ksm-process-and-sysfs-knobs +21 -0
@@ -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(struc }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, };
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Patches currently in -mm which might be from [email protected] are