From: Michal Hocko <mhocko@kernel.org>
To: Ebru Akagunduz <ebru.akagunduz@gmail.com>
Cc: linux-mm@kvack.org, hughd@google.com, riel@redhat.com,
akpm@linux-foundation.org, kirill.shutemov@linux.intel.com,
n-horiguchi@ah.jp.nec.com, aarcange@redhat.com,
iamjoonsoo.kim@lge.com, gorcunov@openvz.org,
linux-kernel@vger.kernel.org, mgorman@suse.de,
rientjes@google.com, vbabka@suse.cz,
aneesh.kumar@linux.vnet.ibm.com, hannes@cmpxchg.org,
boaz@plexistor.com
Subject: Re: [RFC PATCH 1/3] mm, thp: revert allocstall comparing
Date: Tue, 14 Jun 2016 09:07:02 +0200 [thread overview]
Message-ID: <20160614070701.GC5681@dhcp22.suse.cz> (raw)
In-Reply-To: <1465672561-29608-2-git-send-email-ebru.akagunduz@gmail.com>
On Sat 11-06-16 22:15:59, 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
I guess it would be easier to simply drop
mm-thp-avoid-unnecessary-swapin-in-khugepaged.patch
> Signed-off-by: Ebru Akagunduz <ebru.akagunduz@gmail.com>
> ---
> 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
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2016-06-14 7:07 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-11 19:15 [RFC PATCH 0/3] mm, thp: convert from optimistic to conservative Ebru Akagunduz
2016-06-11 19:15 ` [RFC PATCH 1/3] mm, thp: revert allocstall comparing Ebru Akagunduz
2016-06-13 18:32 ` Ebru Akagunduz
2016-06-14 7:07 ` Michal Hocko [this message]
2016-06-11 19:16 ` [RFC PATCH 2/3] mm, thp: convert from optimistic to conservative Ebru Akagunduz
2016-06-13 18:35 ` Ebru Akagunduz
2016-06-14 7:18 ` Michal Hocko
2016-06-15 6:40 ` Minchan Kim
2016-06-16 9:08 ` Ebru Akagunduz
2016-06-11 19:16 ` [RFC PATCH 3/3] doc: add information about min_ptes_young Ebru Akagunduz
2016-06-13 18:37 ` Ebru Akagunduz
2016-06-13 18:30 ` [RFC PATCH 0/3] mm, thp: convert from optimistic to conservative Ebru Akagunduz
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20160614070701.GC5681@dhcp22.suse.cz \
--to=mhocko@kernel.org \
--cc=aarcange@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=aneesh.kumar@linux.vnet.ibm.com \
--cc=boaz@plexistor.com \
--cc=ebru.akagunduz@gmail.com \
--cc=gorcunov@openvz.org \
--cc=hannes@cmpxchg.org \
--cc=hughd@google.com \
--cc=iamjoonsoo.kim@lge.com \
--cc=kirill.shutemov@linux.intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mgorman@suse.de \
--cc=n-horiguchi@ah.jp.nec.com \
--cc=riel@redhat.com \
--cc=rientjes@google.com \
--cc=vbabka@suse.cz \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).