From: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
To: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Subject: Re: [RFC][PATCHv2 2/8] zsmalloc: partial page ordering within a fullness_list
Date: Tue, 16 Jun 2015 23:30:11 +0900 [thread overview]
Message-ID: <20150616143011.GB20596@swordfish> (raw)
In-Reply-To: <20150616131903.GA31387@blaptop>
Hello,
On (06/16/15 22:19), Minchan Kim wrote:
> Hello Sergey,
>
> On Fri, Jun 05, 2015 at 09:03:52PM +0900, Sergey Senozhatsky wrote:
> > We want to see more ZS_FULL pages and less ZS_ALMOST_{FULL, EMPTY}
> > pages. Put a page with higher ->inuse count first within its
> > ->fullness_list, which will give us better chances to fill up this
> > page with new objects (find_get_zspage() return ->fullness_list head
> > for new object allocation), so some zspages will become
> > ZS_ALMOST_FULL/ZS_FULL quicker.
> >
> > It performs a trivial and cheap ->inuse compare which does not slow
> > down zsmalloc, and in the worst case it keeps the list pages not in
> > any particular order, just like we do it now.
>
> Fair enough.
>
> I think it would be better with small cost and it matches current
> zsmalloc design which allocates a object from ALMOST_FULL zspage
> first to reduce memory footprint.
>
> Although we uses page->lru to link zspages, it's not lru order
> so I like your idea.
>
> One think I want to say is it doesn't need to be part of this patchset.
> I hope you gives some data to prove gain and includes it in changelog
> and resubmit, please.
OK, I'll do some testing and come back with some numbers.
Well, none of these patches will get into 4.2, so splitting
the patchset will make things a bit less easy, but I guess I
can do this.
-ss
> >
> > A more expensive solution could sort fullness_list by ->inuse count.
> >
> > Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
> > ---
> > mm/zsmalloc.c | 12 ++++++++++--
> > 1 file changed, 10 insertions(+), 2 deletions(-)
> >
> > diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
> > index ce3310c..cd37bda 100644
> > --- a/mm/zsmalloc.c
> > +++ b/mm/zsmalloc.c
> > @@ -658,8 +658,16 @@ static void insert_zspage(struct page *page, struct size_class *class,
> > return;
> >
> > head = &class->fullness_list[fullness];
> > - if (*head)
> > - list_add_tail(&page->lru, &(*head)->lru);
> > + if (*head) {
> > + /*
> > + * We want to see more ZS_FULL pages and less almost
> > + * empty/full. Put pages with higher ->inuse first.
> > + */
> > + if (page->inuse < (*head)->inuse)
> > + list_add_tail(&page->lru, &(*head)->lru);
> > + else
> > + list_add(&page->lru, &(*head)->lru);
> > + }
> >
> > *head = page;
> > zs_stat_inc(class, fullness == ZS_ALMOST_EMPTY ?
> > --
> > 2.4.2.387.gf86f31a
> >
>
> --
> Kind regards,
> Minchan Kim
>
WARNING: multiple messages have this Message-ID (diff)
From: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
To: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Subject: Re: [RFC][PATCHv2 2/8] zsmalloc: partial page ordering within a fullness_list
Date: Tue, 16 Jun 2015 23:30:11 +0900 [thread overview]
Message-ID: <20150616143011.GB20596@swordfish> (raw)
In-Reply-To: <20150616131903.GA31387@blaptop>
Hello,
On (06/16/15 22:19), Minchan Kim wrote:
> Hello Sergey,
>
> On Fri, Jun 05, 2015 at 09:03:52PM +0900, Sergey Senozhatsky wrote:
> > We want to see more ZS_FULL pages and less ZS_ALMOST_{FULL, EMPTY}
> > pages. Put a page with higher ->inuse count first within its
> > ->fullness_list, which will give us better chances to fill up this
> > page with new objects (find_get_zspage() return ->fullness_list head
> > for new object allocation), so some zspages will become
> > ZS_ALMOST_FULL/ZS_FULL quicker.
> >
> > It performs a trivial and cheap ->inuse compare which does not slow
> > down zsmalloc, and in the worst case it keeps the list pages not in
> > any particular order, just like we do it now.
>
> Fair enough.
>
> I think it would be better with small cost and it matches current
> zsmalloc design which allocates a object from ALMOST_FULL zspage
> first to reduce memory footprint.
>
> Although we uses page->lru to link zspages, it's not lru order
> so I like your idea.
>
> One think I want to say is it doesn't need to be part of this patchset.
> I hope you gives some data to prove gain and includes it in changelog
> and resubmit, please.
OK, I'll do some testing and come back with some numbers.
Well, none of these patches will get into 4.2, so splitting
the patchset will make things a bit less easy, but I guess I
can do this.
-ss
> >
> > A more expensive solution could sort fullness_list by ->inuse count.
> >
> > Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
> > ---
> > mm/zsmalloc.c | 12 ++++++++++--
> > 1 file changed, 10 insertions(+), 2 deletions(-)
> >
> > diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
> > index ce3310c..cd37bda 100644
> > --- a/mm/zsmalloc.c
> > +++ b/mm/zsmalloc.c
> > @@ -658,8 +658,16 @@ static void insert_zspage(struct page *page, struct size_class *class,
> > return;
> >
> > head = &class->fullness_list[fullness];
> > - if (*head)
> > - list_add_tail(&page->lru, &(*head)->lru);
> > + if (*head) {
> > + /*
> > + * We want to see more ZS_FULL pages and less almost
> > + * empty/full. Put pages with higher ->inuse first.
> > + */
> > + if (page->inuse < (*head)->inuse)
> > + list_add_tail(&page->lru, &(*head)->lru);
> > + else
> > + list_add(&page->lru, &(*head)->lru);
> > + }
> >
> > *head = page;
> > zs_stat_inc(class, fullness == ZS_ALMOST_EMPTY ?
> > --
> > 2.4.2.387.gf86f31a
> >
>
> --
> Kind regards,
> Minchan Kim
>
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2015-06-16 14:31 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-05 12:03 [RFC][PATCHv2 0/8] introduce automatic pool compaction Sergey Senozhatsky
2015-06-05 12:03 ` Sergey Senozhatsky
2015-06-05 12:03 ` [RFC][PATCHv2 1/8] zsmalloc: drop unused variable `nr_to_migrate' Sergey Senozhatsky
2015-06-05 12:03 ` Sergey Senozhatsky
2015-06-05 12:03 ` [RFC][PATCHv2 2/8] zsmalloc: partial page ordering within a fullness_list Sergey Senozhatsky
2015-06-05 12:03 ` Sergey Senozhatsky
2015-06-16 13:19 ` Minchan Kim
2015-06-16 13:19 ` Minchan Kim
2015-06-16 14:30 ` Sergey Senozhatsky [this message]
2015-06-16 14:30 ` Sergey Senozhatsky
2015-06-05 12:03 ` [RFC][PATCHv2 3/8] zsmalloc: lower ZS_ALMOST_FULL waterline Sergey Senozhatsky
2015-06-05 12:03 ` Sergey Senozhatsky
2015-06-16 13:37 ` Minchan Kim
2015-06-16 13:37 ` Minchan Kim
2015-06-16 14:35 ` Sergey Senozhatsky
2015-06-16 14:35 ` Sergey Senozhatsky
2015-06-05 12:03 ` [RFC][PATCHv2 4/8] zsmalloc: always keep per-class stats Sergey Senozhatsky
2015-06-05 12:03 ` Sergey Senozhatsky
2015-06-05 12:03 ` [RFC][PATCHv2 5/8] zsmalloc: introduce zs_can_compact() function Sergey Senozhatsky
2015-06-05 12:03 ` Sergey Senozhatsky
2015-06-16 14:19 ` Minchan Kim
2015-06-16 14:19 ` Minchan Kim
2015-06-16 14:41 ` Sergey Senozhatsky
2015-06-16 14:41 ` Sergey Senozhatsky
2015-06-05 12:03 ` [RFC][PATCHv2 6/8] zsmalloc: cosmetic compaction code adjustments Sergey Senozhatsky
2015-06-05 12:03 ` Sergey Senozhatsky
2015-06-05 12:03 ` [RFC][PATCHv2 7/8] zsmalloc/zram: move `num_migrated' to zs_pool Sergey Senozhatsky
2015-06-05 12:03 ` Sergey Senozhatsky
2015-06-05 12:03 ` [RFC][PATCHv2 8/8] zsmalloc: register a shrinker to trigger auto-compaction Sergey Senozhatsky
2015-06-05 12:03 ` Sergey Senozhatsky
2015-06-16 14:47 ` Minchan Kim
2015-06-16 14:47 ` Minchan Kim
2015-06-16 15:45 ` Sergey Senozhatsky
2015-06-16 15:45 ` Sergey Senozhatsky
2015-06-18 1:50 ` Minchan Kim
2015-06-18 1:50 ` Minchan Kim
2015-06-18 2:41 ` Sergey Senozhatsky
2015-06-18 2:41 ` Sergey Senozhatsky
2015-06-18 3:01 ` Sergey Senozhatsky
2015-06-18 3:01 ` Sergey Senozhatsky
2015-06-18 3:46 ` Minchan Kim
2015-06-18 3:46 ` Minchan Kim
2015-06-18 3:39 ` Minchan Kim
2015-06-18 3:39 ` Minchan Kim
2015-06-18 3:58 ` Sergey Senozhatsky
2015-06-18 3:58 ` Sergey Senozhatsky
2015-06-17 7:11 ` Sergey Senozhatsky
2015-06-17 7:11 ` Sergey Senozhatsky
2015-06-10 0:04 ` [RFC][PATCHv2 0/8] introduce automatic pool compaction Minchan Kim
2015-06-10 0:04 ` Minchan Kim
2015-06-10 0:07 ` Sergey Senozhatsky
2015-06-10 0:07 ` Sergey Senozhatsky
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=20150616143011.GB20596@swordfish \
--to=sergey.senozhatsky@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=minchan@kernel.org \
--cc=sergey.senozhatsky.work@gmail.com \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.