Messages in this thread Patch in this message | | | From | "Huang, Ying" <> | Subject | [PATCH -mm -v3 5/6] mm, swap: Add sysfs interface for VMA based swap readahead | Date | Tue, 25 Jul 2017 09:51:50 +0800 |
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From: Huang Ying <ying.huang@intel.com>
The sysfs interface to control the VMA based swap readahead is added as follow,
/sys/kernel/mm/swap/vma_ra_enabled
Enable the VMA based swap readahead algorithm, or use the original global swap readahead algorithm.
/sys/kernel/mm/swap/vma_ra_max_order
Set the max order of the readahead window size for the VMA based swap readahead algorithm.
Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@redhat.com> Cc: Shaohua Li <shli@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Tim Chen <tim.c.chen@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> --- mm/swap_state.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 47 insertions(+)
diff --git a/mm/swap_state.c b/mm/swap_state.c index 730477d86f15..46717088bd9f 100644 --- a/mm/swap_state.c +++ b/mm/swap_state.c @@ -820,6 +820,51 @@ static ssize_t swap_readahead_total_show( static struct kobj_attribute swap_readahead_total_attr = __ATTR(ra_total, 0444, swap_readahead_total_show, NULL); +static ssize_t vma_ra_enabled_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sprintf(buf, "%s\n", swap_vma_readahead ? "true" : "false"); +} +static ssize_t vma_ra_enabled_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t count) +{ + if (!strncmp(buf, "true", 4) || !strncmp(buf, "1", 1)) + swap_vma_readahead = true; + else if (!strncmp(buf, "false", 5) || !strncmp(buf, "0", 1)) + swap_vma_readahead = false; + else + return -EINVAL; + + return count; +} +static struct kobj_attribute vma_ra_enabled_attr = + __ATTR(vma_ra_enabled, 0644, vma_ra_enabled_show, + vma_ra_enabled_store); + +static ssize_t vma_ra_max_order_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sprintf(buf, "%d\n", swap_ra_max_order); +} +static ssize_t vma_ra_max_order_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t count) +{ + int err, v; + + err = kstrtoint(buf, 10, &v); + if (err || v > SWAP_RA_ORDER_CEILING || v <= 0) + return -EINVAL; + + swap_ra_max_order = v; + + return count; +} +static struct kobj_attribute vma_ra_max_order_attr = + __ATTR(vma_ra_max_order, 0644, vma_ra_max_order_show, + vma_ra_max_order_store); + static struct attribute *swap_attrs[] = { &swap_cache_pages_attr.attr, &swap_cache_add_attr.attr, @@ -828,6 +873,8 @@ static struct attribute *swap_attrs[] = { &swap_cache_find_total_attr.attr, &swap_readahead_hits_attr.attr, &swap_readahead_total_attr.attr, + &vma_ra_enabled_attr.attr, + &vma_ra_max_order_attr.attr, NULL, }; -- 2.13.2
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