diff mbox series

[v1,2/4] mm/ksm: add sysfs knobs for advisor

Message ID 20231004190249.829015-3-shr@devkernel.io (mailing list archive)
State New
Headers show
Series mm/ksm: Add ksm advisor | expand

Commit Message

Stefan Roesch Oct. 4, 2023, 7:02 p.m. UTC 
This adds four new knobs for the KSM advisor to influence its behaviour.
The knobs are:

- advisor_mode:
    0: no advisor (default)
    1: scan time advisor
- advisor_min_pages: 500 (default)
- advisor_max_pages: 5000 (default)
- advisor_target_scan_time: 200 (default in seconds)

The new values will take effect on the next scan round.

Signed-off-by: Stefan Roesch <shr@devkernel.io>
---
 mm/ksm.c | 108 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 108 insertions(+)

Comments

kernel test robot Oct. 5, 2023, 5:57 p.m. UTC | #1 
Hi Stefan,

kernel test robot noticed the following build errors:

[auto build test ERROR on 12d04a7bf0da67321229d2bc8b1a7074d65415a9]

url:    https://github.com/intel-lab-lkp/linux/commits/Stefan-Roesch/mm-ksm-add-ksm-advisor/20231005-030402
base:   12d04a7bf0da67321229d2bc8b1a7074d65415a9
patch link:    https://lore.kernel.org/r/20231004190249.829015-3-shr%40devkernel.io
patch subject: [PATCH v1 2/4] mm/ksm: add sysfs knobs for advisor
config: i386-buildonly-randconfig-002-20231006 (https://download.01.org/0day-ci/archive/20231006/202310060119.K002rbE5-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231006/202310060119.K002rbE5-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202310060119.K002rbE5-lkp@intel.com/

All errors (new ones prefixed by >>):

   ld: mm/ksm.o: in function `scan_get_next_rmap_item':
>> ksm.c:(.text+0x3e45): undefined reference to `__divdi3'
>> ld: ksm.c:(.text+0x3e88): undefined reference to `__divdi3'
   ld: ksm.c:(.text+0x3ed9): undefined reference to `__divdi3'
kernel test robot Oct. 5, 2023, 9:36 p.m. UTC | #2 
Hi Stefan,

kernel test robot noticed the following build errors:

[auto build test ERROR on 12d04a7bf0da67321229d2bc8b1a7074d65415a9]

url:    https://github.com/intel-lab-lkp/linux/commits/Stefan-Roesch/mm-ksm-add-ksm-advisor/20231005-030402
base:   12d04a7bf0da67321229d2bc8b1a7074d65415a9
patch link:    https://lore.kernel.org/r/20231004190249.829015-3-shr%40devkernel.io
patch subject: [PATCH v1 2/4] mm/ksm: add sysfs knobs for advisor
config: arm-randconfig-001-20231006 (https://download.01.org/0day-ci/archive/20231006/202310060504.eMl8wb3o-lkp@intel.com/config)
compiler: arm-linux-gnueabi-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231006/202310060504.eMl8wb3o-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202310060504.eMl8wb3o-lkp@intel.com/

All errors (new ones prefixed by >>):

   arm-linux-gnueabi-ld: mm/ksm.o: in function `run_advisor':
>> ksm.c:(.text+0x21e8): undefined reference to `__aeabi_ldivmod'
>> arm-linux-gnueabi-ld: ksm.c:(.text+0x2290): undefined reference to `__aeabi_ldivmod'
   arm-linux-gnueabi-ld: ksm.c:(.text+0x22cc): undefined reference to `__aeabi_ldivmod'
diff mbox series

Patch

diff --git a/mm/ksm.c b/mm/ksm.c
index c9edfb293024..12e70f806b2b 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -341,6 +341,14 @@  static void init_advisor(void)
 	advisor_ctx.change = 0;
 }
 
+static void set_advisor_defaults(void)
+{
+	if (ksm_advisor == KSM_ADVISOR_NONE)
+		ksm_thread_pages_to_scan = DEFAULT_PAGES_TO_SCAN;
+	else if (ksm_advisor == KSM_ADVISOR_SCAN_TIME)
+		ksm_thread_pages_to_scan = ksm_advisor_min_pages;
+}
+
 /*
  * Use previous scan time if available, otherwise use current scan time as an
  * approximation for the previous scan time.
@@ -3692,6 +3700,102 @@  static ssize_t smart_scan_store(struct kobject *kobj,
 }
 KSM_ATTR(smart_scan);
 
+static ssize_t advisor_mode_show(struct kobject *kobj,
+				 struct kobj_attribute *attr, char *buf)
+{
+	return sysfs_emit(buf, "%u\n", ksm_advisor);
+}
+
+static ssize_t advisor_mode_store(struct kobject *kobj,
+				  struct kobj_attribute *attr, const char *buf,
+				  size_t count)
+{
+	unsigned int mode;
+	int err;
+
+	err = kstrtouint(buf, 10, &mode);
+	if (err)
+		return -EINVAL;
+	if (mode > KSM_ADVISOR_LAST)
+		return -EINVAL;
+
+	/* Set advisor default values */
+	ksm_advisor = mode;
+	init_advisor();
+	set_advisor_defaults();
+
+	return count;
+}
+KSM_ATTR(advisor_mode);
+
+static ssize_t advisor_min_pages_show(struct kobject *kobj,
+				      struct kobj_attribute *attr, char *buf)
+{
+	return sysfs_emit(buf, "%lu\n", ksm_advisor_min_pages);
+}
+
+static ssize_t advisor_min_pages_store(struct kobject *kobj,
+				       struct kobj_attribute *attr,
+				       const char *buf, size_t count)
+{
+	int err;
+	unsigned long value;
+
+	err = kstrtoul(buf, 10, &value);
+	if (err)
+		return -EINVAL;
+
+	ksm_advisor_min_pages = value;
+	return count;
+}
+KSM_ATTR(advisor_min_pages);
+
+static ssize_t advisor_max_pages_show(struct kobject *kobj,
+				      struct kobj_attribute *attr, char *buf)
+{
+	return sysfs_emit(buf, "%lu\n", ksm_advisor_max_pages);
+}
+
+static ssize_t advisor_max_pages_store(struct kobject *kobj,
+				       struct kobj_attribute *attr,
+				       const char *buf, size_t count)
+{
+	int err;
+	unsigned long value;
+
+	err = kstrtoul(buf, 10, &value);
+	if (err)
+		return -EINVAL;
+
+	ksm_advisor_max_pages = value;
+	return count;
+}
+KSM_ATTR(advisor_max_pages);
+
+static ssize_t advisor_target_scan_time_show(struct kobject *kobj,
+					     struct kobj_attribute *attr, char *buf)
+{
+	return sysfs_emit(buf, "%lu\n", ksm_advisor_target_scan_time);
+}
+
+static ssize_t advisor_target_scan_time_store(struct kobject *kobj,
+					      struct kobj_attribute *attr,
+					      const char *buf, size_t count)
+{
+	int err;
+	unsigned long value;
+
+	err = kstrtoul(buf, 10, &value);
+	if (err)
+		return -EINVAL;
+	if (value < 1)
+		return -EINVAL;
+
+	ksm_advisor_target_scan_time = value;
+	return count;
+}
+KSM_ATTR(advisor_target_scan_time);
+
 static struct attribute *ksm_attrs[] = {
 	&sleep_millisecs_attr.attr,
 	&pages_to_scan_attr.attr,
@@ -3714,6 +3818,10 @@  static struct attribute *ksm_attrs[] = {
 	&use_zero_pages_attr.attr,
 	&general_profit_attr.attr,
 	&smart_scan_attr.attr,
+	&advisor_mode_attr.attr,
+	&advisor_min_pages_attr.attr,
+	&advisor_max_pages_attr.attr,
+	&advisor_target_scan_time_attr.attr,
 	NULL,
 };