On Sat, Jun 11, 2016 at 10:15:59PM +0300, Ebru Akagunduz wrote: > This patch takes back allocstall comparing when deciding > whether swapin worthwhile because it does not work, > if vmevent disabled. > > Related commit: > http://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/commit/?id=2548306628308aa6a326640d345a737bc898941d > > Signed-off-by: Ebru Akagunduz <ebru.akagunduz@xxxxxxxxx> Suggested-by: Minchan Kim <minchan@xxxxxxxxxx> > --- Cc'ed Minchan Kim. > mm/khugepaged.c | 31 ++++++++----------------------- > 1 file changed, 8 insertions(+), 23 deletions(-) > > diff --git a/mm/khugepaged.c b/mm/khugepaged.c > index 0ac63f7..e3d8da7 100644 > --- a/mm/khugepaged.c > +++ b/mm/khugepaged.c > @@ -68,7 +68,6 @@ static DECLARE_WAIT_QUEUE_HEAD(khugepaged_wait); > */ > static unsigned int khugepaged_max_ptes_none __read_mostly; > static unsigned int khugepaged_max_ptes_swap __read_mostly; > -static unsigned long allocstall; > > static int khugepaged(void *none); > > @@ -926,7 +925,6 @@ static void collapse_huge_page(struct mm_struct *mm, > struct page *new_page; > spinlock_t *pmd_ptl, *pte_ptl; > int isolated = 0, result = 0; > - unsigned long swap, curr_allocstall; > struct mem_cgroup *memcg; > unsigned long mmun_start; /* For mmu_notifiers */ > unsigned long mmun_end; /* For mmu_notifiers */ > @@ -955,8 +953,6 @@ static void collapse_huge_page(struct mm_struct *mm, > goto out_nolock; > } > > - swap = get_mm_counter(mm, MM_SWAPENTS); > - curr_allocstall = sum_vm_event(ALLOCSTALL); > down_read(&mm->mmap_sem); > result = hugepage_vma_revalidate(mm, address); > if (result) { > @@ -972,22 +968,15 @@ static void collapse_huge_page(struct mm_struct *mm, > up_read(&mm->mmap_sem); > goto out_nolock; > } > - > /* > - * Don't perform swapin readahead when the system is under pressure, > - * to avoid unnecessary resource consumption. > + * __collapse_huge_page_swapin always returns with mmap_sem > + * locked. If it fails, release mmap_sem and jump directly > + * out. Continuing to collapse causes inconsistency. > */ > - if (allocstall == curr_allocstall && swap != 0) { > - /* > - * __collapse_huge_page_swapin always returns with mmap_sem > - * locked. If it fails, release mmap_sem and jump directly > - * out. Continuing to collapse causes inconsistency. > - */ > - if (!__collapse_huge_page_swapin(mm, vma, address, pmd)) { > - mem_cgroup_cancel_charge(new_page, memcg, true); > - up_read(&mm->mmap_sem); > - goto out_nolock; > - } > + if (!__collapse_huge_page_swapin(mm, vma, address, pmd)) { > + mem_cgroup_cancel_charge(new_page, memcg, true); > + up_read(&mm->mmap_sem); > + goto out_nolock; > } > > up_read(&mm->mmap_sem); > @@ -1822,7 +1811,6 @@ static void khugepaged_wait_work(void) > if (!scan_sleep_jiffies) > return; > > - allocstall = sum_vm_event(ALLOCSTALL); > khugepaged_sleep_expire = jiffies + scan_sleep_jiffies; > wait_event_freezable_timeout(khugepaged_wait, > khugepaged_should_wakeup(), > @@ -1830,10 +1818,8 @@ static void khugepaged_wait_work(void) > return; > } > > - if (khugepaged_enabled()) { > - allocstall = sum_vm_event(ALLOCSTALL); > + if (khugepaged_enabled()) > wait_event_freezable(khugepaged_wait, khugepaged_wait_event()); > - } > } > > static int khugepaged(void *none) > @@ -1842,7 +1828,6 @@ static int khugepaged(void *none) > > set_freezable(); > set_user_nice(current, MAX_NICE); > - allocstall = sum_vm_event(ALLOCSTALL); > > while (!kthread_should_stop()) { > khugepaged_do_scan(); > -- > 1.9.1 > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>