diff options
| author |   David Rientjes <rientjes@google.com> | 2016-05-20 16:58:56 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2016-05-20 17:58:30 -0700 |
| commit | f0508977787b3bcfd54e82111ab50d6245b9f4df (patch) | |
| tree | 2ee4d47b6d18ad76ddcb919fe3bd76f4d4e1bdc4 /mm | |
| parent | MM: increase safety margin provided by PF_LESS_THROTTLE (diff) | |
| download | linux-dev-f0508977787b3bcfd54e82111ab50d6245b9f4df.tar.xz linux-dev-f0508977787b3bcfd54e82111ab50d6245b9f4df.zip | |
mm, thp: khugepaged should scan when sleep value is written
If a large value is written to scan_sleep_millisecs, for example, that
period must lapse before khugepaged will wake up for periodic
collapsing.
If this value is tuned to 1 day, for example, and then re-tuned to its
default 10s, khugepaged will still wait for a day before scanning again.
This patch causes khugepaged to wakeup immediately when the value is
changed and then sleep until that value is rewritten or the new value
lapses.
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1605181453200.4786@chino.kir.corp.google.com
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/huge_memory.c | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 1764184c4774..41ef7547e822 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -89,6 +89,7 @@ static unsigned int khugepaged_full_scans; static unsigned int khugepaged_scan_sleep_millisecs __read_mostly = 10000; /* during fragmentation poll the hugepage allocator once every minute */ static unsigned int khugepaged_alloc_sleep_millisecs __read_mostly = 60000; +static unsigned long khugepaged_sleep_expire; static struct task_struct *khugepaged_thread __read_mostly; static DEFINE_MUTEX(khugepaged_mutex); static DEFINE_SPINLOCK(khugepaged_mm_lock); @@ -467,6 +468,7 @@ static ssize_t scan_sleep_millisecs_store(struct kobject *kobj, return -EINVAL; khugepaged_scan_sleep_millisecs = msecs; + khugepaged_sleep_expire = 0; wake_up_interruptible(&khugepaged_wait); return count; @@ -494,6 +496,7 @@ static ssize_t alloc_sleep_millisecs_store(struct kobject *kobj, return -EINVAL; khugepaged_alloc_sleep_millisecs = msecs; + khugepaged_sleep_expire = 0; wake_up_interruptible(&khugepaged_wait); return count; @@ -2791,15 +2794,25 @@ static void khugepaged_do_scan(void) put_page(hpage); } +static bool khugepaged_should_wakeup(void) +{ + return kthread_should_stop() || + time_after_eq(jiffies, khugepaged_sleep_expire); +} + static void khugepaged_wait_work(void) { if (khugepaged_has_work()) { - if (!khugepaged_scan_sleep_millisecs) + const unsigned long scan_sleep_jiffies = + msecs_to_jiffies(khugepaged_scan_sleep_millisecs); + + if (!scan_sleep_jiffies) return; + khugepaged_sleep_expire = jiffies + scan_sleep_jiffies; wait_event_freezable_timeout(khugepaged_wait, - kthread_should_stop(), - msecs_to_jiffies(khugepaged_scan_sleep_millisecs)); + khugepaged_should_wakeup(), + scan_sleep_jiffies); return; } |