From a42dde04152750426cc620fd277e80fffae2f65a Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 30 Apr 2008 00:54:36 -0700 Subject: mm: bdi: allow setting a maximum for the bdi dirty limit Add "max_ratio" to /sys/class/bdi. This indicates the maximum percentage of the global dirty threshold allocated to this bdi. [mszeredi@suse.cz] - fix parsing in max_ratio_store(). - export bdi_set_max_ratio() to modules - limit bdi_dirty with bdi->max_ratio - document new sysfs attribute Signed-off-by: Peter Zijlstra Signed-off-by: Miklos Szeredi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/backing-dev.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) (limited to 'mm/backing-dev.c') diff --git a/mm/backing-dev.c b/mm/backing-dev.c index 4967fb176e53..08361b6aad50 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -73,6 +73,24 @@ static ssize_t min_ratio_store(struct device *dev, } BDI_SHOW(min_ratio, bdi->min_ratio) +static ssize_t max_ratio_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t count) +{ + struct backing_dev_info *bdi = dev_get_drvdata(dev); + char *end; + unsigned int ratio; + ssize_t ret = -EINVAL; + + ratio = simple_strtoul(buf, &end, 10); + if (*buf && (end[0] == '\0' || (end[0] == '\n' && end[1] == '\0'))) { + ret = bdi_set_max_ratio(bdi, ratio); + if (!ret) + ret = count; + } + return ret; +} +BDI_SHOW(max_ratio, bdi->max_ratio) + #define __ATTR_RW(attr) __ATTR(attr, 0644, attr##_show, attr##_store) static struct device_attribute bdi_dev_attrs[] = { @@ -82,6 +100,7 @@ static struct device_attribute bdi_dev_attrs[] = { __ATTR_RO(dirty_kb), __ATTR_RO(bdi_dirty_kb), __ATTR_RW(min_ratio), + __ATTR_RW(max_ratio), __ATTR_NULL, }; @@ -147,6 +166,8 @@ int bdi_init(struct backing_dev_info *bdi) bdi->dev = NULL; bdi->min_ratio = 0; + bdi->max_ratio = 100; + bdi->max_prop_frac = PROP_FRAC_BASE; for (i = 0; i < NR_BDI_STAT_ITEMS; i++) { err = percpu_counter_init_irq(&bdi->bdi_stat[i], 0); -- cgit v1.2.3-55-g7522