[PATCH 09/20] staging/lustre/obdclass: move max_dirty_mb from sysctl to sysfs

green
2015-07-06T16:53:17Z

max_dirty_mb is now a parameter in /sys/fs/lustre/

Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
---
.../lustre/lustre/obdclass/linux/linux-sysctl.c | 74 +++++++++-------------
drivers/staging/lustre/sysfs-fs-lustre | 12 ++++
2 files changed, 43 insertions(+), 43 deletions(-)

diff --git a/drivers/staging/lustre/lustre/obdclass/linux/linux-sysctl.c b/drivers/staging/lustre/lustre/obdclass/linux/linux-sysctl.c
index 3c8087b..bb55a07 100644
--- a/drivers/staging/lustre/lustre/obdclass/linux/linux-sysctl.c
+++ b/drivers/staging/lustre/lustre/obdclass/linux/linux-sysctl.c
@@ -100,48 +100,42 @@ static struct static_lustre_uintvalue_attr lustre_sattr_##name = \

LUSTRE_STATIC_UINT_ATTR(timeout, &obd_timeout);

-#ifdef CONFIG_SYSCTL
-static int proc_max_dirty_pages_in_mb(struct ctl_table *table, int write,
- void __user *buffer, size_t *lenp, loff_t *ppos)
+static ssize_t max_dirty_mb_show(struct kobject *kobj, struct attribute *attr,
+ char *buf)
{
- int rc = 0;
+ return sprintf(buf, "%ul\n",
+ obd_max_dirty_pages / (1 << (20 - PAGE_CACHE_SHIFT)));
+}
+
+static ssize_t max_dirty_mb_store(struct kobject *kobj, struct attribute *attr,
+ const char *buffer, size_t count)
+{
+ int rc;
+ unsigned long val;
+
+ rc = kstrtoul(buffer, 10, &val);
+ if (rc)
+ return rc;
+
+ val *= 1 << (20 - PAGE_CACHE_SHIFT); /* convert to pages */

- if (!table->data || !table->maxlen || !*lenp || (*ppos && !write)) {
- *lenp = 0;
- return 0;
+ if (val > ((totalram_pages / 10) * 9)) {
+ /* Somebody wants to assign too much memory to dirty pages */
+ return -EINVAL;
}
- if (write) {
- rc = lprocfs_write_frac_helper(buffer, *lenp,
- (unsigned int *)table->data,
- 1 << (20 - PAGE_CACHE_SHIFT));
- /* Don't allow them to let dirty pages exceed 90% of system
- * memory and set a hard minimum of 4MB. */
- if (obd_max_dirty_pages > ((totalram_pages / 10) * 9)) {
- CERROR("Refusing to set max dirty pages to %u, which is more than 90%% of available RAM; setting to %lu\n",
- obd_max_dirty_pages,
- ((totalram_pages / 10) * 9));
- obd_max_dirty_pages = (totalram_pages / 10) * 9;
- } else if (obd_max_dirty_pages < 4 << (20 - PAGE_CACHE_SHIFT)) {
- obd_max_dirty_pages = 4 << (20 - PAGE_CACHE_SHIFT);
- }
- } else {
- char buf[21];
- int len;
-
- len = lprocfs_read_frac_helper(buf, sizeof(buf),
- *(unsigned int *)table->data,
- 1 << (20 - PAGE_CACHE_SHIFT));
- if (len > *lenp)
- len = *lenp;
- buf[len] = '\0';
- if (copy_to_user(buffer, buf, len))
- return -EFAULT;
- *lenp = len;
+
+ if (val < 4 << (20 - PAGE_CACHE_SHIFT)) {
+ /* Less than 4 Mb for dirty cache is also bad */
+ return -EINVAL;
}
- *ppos += *lenp;
- return rc;
+
+ obd_max_dirty_pages = val;
+
+ return count;
}
+LUSTRE_RW_ATTR(max_dirty_mb);

+#ifdef CONFIG_SYSCTL
static struct ctl_table obd_table[] = {
{
.procname = "debug_peer_on_timeout",
@@ -165,13 +159,6 @@ static struct ctl_table obd_table[] = {
.proc_handler = &proc_dointvec
},
{
- .procname = "max_dirty_mb",
- .data = &obd_max_dirty_pages,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = &proc_max_dirty_pages_in_mb
- },
- {
.procname = "at_min",
.data = &at_min,
.maxlen = sizeof(int),
@@ -223,6 +210,7 @@ static struct ctl_table parent_table[] = {

static struct attribute *lustre_attrs[] = {
&lustre_sattr_timeout.u.attr,
+ &lustre_attr_max_dirty_mb.attr,
NULL,
};

diff --git a/drivers/staging/lustre/sysfs-fs-lustre b/drivers/staging/lustre/sysfs-fs-lustre
index 6dbad26..38d1adc 100644
--- a/drivers/staging/lustre/sysfs-fs-lustre
+++ b/drivers/staging/lustre/sysfs-fs-lustre
@@ -52,6 +52,18 @@ Description:
AT (adaptive timeouts).
Unit: seconds, default: 100

+What: /sys/fs/lustre/max_dirty_mb
+Date: June 2015
+Contact: "Oleg Drokin" <oleg.drokin@intel.com>
+Description:
+ Controls total number of dirty cache (in megabytes) allowed
+ across all mounted lustre filesystems.
+ Since writeout of dirty pages in Lustre is somewhat expensive,
+ when you allow to many dirty pages, this might lead to
+ performance degradations as kernel tries to desperately
+ find some pages to free/writeout.
+ Default 1/2 RAM. Min value 4, max value 9/10 of RAM.
+
What: /sys/fs/lustre/llite/<fsname>-<uuid>/blocksize
Date: May 2015
Contact: "Oleg Drokin" <oleg.drokin@intel.com>
--
2.1.0