From: Srividya Desireddy <srividya.dr@samsung.com> To: Dan Streetman <ddstreet@ieee.org>, "sjenning@redhat.com" <sjenning@redhat.com>, "linux-mm@kvack.org" <linux-mm@kvack.org>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org> Cc: Dinakar Reddy Pathireddy <dinakar.p@samsung.com>, RAJIB BASU <rajib.basu@samsung.com>, Srikanth Mandalapu <srikanth.m@samsung.com>, SHARAN ALLUR <sharan.allur@samsung.com>, JUHUN KIM <juhunkim@samsung.com>, Srividya Desireddy <srividya.dr@samsung.com>, "srividya.desireddy@gmail.com" <srividya.desireddy@gmail.com> Subject: [PATCH] zswap: Update with same-value filled page feature Date: Wed, 29 Nov 2017 15:34:37 +0000 [thread overview] Message-ID: <20171129153437epcms5p64b04efa370cc42bb0f9e5677e298704e@epcms5p6> (raw) In-Reply-To: <CALZtONA1R8HyODqUP8Z-0yxvRAsV=Zo8OD2PQT3HwWWmqE6Hig@mail.gmail.com> From: Srividya Desireddy <srividya.dr@samsung.com> Date: Wed, 29 Nov 2017 20:23:15 +0530 Subject: [PATCH] zswap: Update with same-value filled page feature Updated zswap document with details on same-value filled pages identification feature. The usage of zswap.same_filled_pages_enabled module parameter is explained. Signed-off-by: Srividya Desireddy <srividya.dr@samsung.com> --- Documentation/vm/zswap.txt | 22 +++++++++++++++++++++- 1 file changed, 21 insertions(+), 1 deletion(-) diff --git a/Documentation/vm/zswap.txt b/Documentation/vm/zswap.txt index 89fff7d..cc015b5 100644 --- a/Documentation/vm/zswap.txt +++ b/Documentation/vm/zswap.txt @@ -98,5 +98,25 @@ request is made for a page in an old zpool, it is uncompressed using its original compressor. Once all pages are removed from an old zpool, the zpool and its compressor are freed. +Some of the pages in zswap are same-value filled pages (i.e. contents of the +page have same value or repetitive pattern). These pages include zero-filled +pages and they are handled differently. During store operation, a page is +checked if it is a same-value filled page before compressing it. If true, the +compressed length of the page is set to zero and the pattern or same-filled +value is stored. + +Same-value filled pages identification feature is enabled by default and can be +disabled at boot time by setting the "same_filled_pages_enabled" attribute to 0, +e.g. zswap.same_filled_pages_enabled=0. It can also be enabled and disabled at +runtime using the sysfs "same_filled_pages_enabled" attribute, e.g. + +echo 1 > /sys/module/zswap/parameters/same_filled_pages_enabled + +When zswap same-filled page identification is disabled at runtime, it will stop +checking for the same-value filled pages during store operation. However, the +existing pages which are marked as same-value filled pages will be loaded or +invalidated. + A debugfs interface is provided for various statistic about pool size, number -of pages stored, and various counters for the reasons pages are rejected. +of pages stored, same-value filled pages and various counters for the reasons +pages are rejected. -- 2.7.4
WARNING: multiple messages have this Message-ID (diff)
From: Srividya Desireddy <srividya.dr@samsung.com> To: Dan Streetman <ddstreet@ieee.org>, "sjenning@redhat.com" <sjenning@redhat.com>, "linux-mm@kvack.org" <linux-mm@kvack.org>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org> Cc: Dinakar Reddy Pathireddy <dinakar.p@samsung.com>, RAJIB BASU <rajib.basu@samsung.com>, Srikanth Mandalapu <srikanth.m@samsung.com>, SHARAN ALLUR <sharan.allur@samsung.com>, JUHUN KIM <juhunkim@samsung.com>, Srividya Desireddy <srividya.dr@samsung.com>, "srividya.desireddy@gmail.com" <srividya.desireddy@gmail.com> Subject: [PATCH] zswap: Update with same-value filled page feature Date: Wed, 29 Nov 2017 15:34:37 +0000 [thread overview] Message-ID: <20171129153437epcms5p64b04efa370cc42bb0f9e5677e298704e@epcms5p6> (raw) In-Reply-To: <CALZtONA1R8HyODqUP8Z-0yxvRAsV=Zo8OD2PQT3HwWWmqE6Hig@mail.gmail.com> From: Srividya Desireddy <srividya.dr@samsung.com> Date: Wed, 29 Nov 2017 20:23:15 +0530 Subject: [PATCH] zswap: Update with same-value filled page feature Updated zswap document with details on same-value filled pages identification feature. The usage of zswap.same_filled_pages_enabled module parameter is explained. Signed-off-by: Srividya Desireddy <srividya.dr@samsung.com> --- Documentation/vm/zswap.txt | 22 +++++++++++++++++++++- 1 file changed, 21 insertions(+), 1 deletion(-) diff --git a/Documentation/vm/zswap.txt b/Documentation/vm/zswap.txt index 89fff7d..cc015b5 100644 --- a/Documentation/vm/zswap.txt +++ b/Documentation/vm/zswap.txt @@ -98,5 +98,25 @@ request is made for a page in an old zpool, it is uncompressed using its original compressor. Once all pages are removed from an old zpool, the zpool and its compressor are freed. +Some of the pages in zswap are same-value filled pages (i.e. contents of the +page have same value or repetitive pattern). These pages include zero-filled +pages and they are handled differently. During store operation, a page is +checked if it is a same-value filled page before compressing it. If true, the +compressed length of the page is set to zero and the pattern or same-filled +value is stored. + +Same-value filled pages identification feature is enabled by default and can be +disabled at boot time by setting the "same_filled_pages_enabled" attribute to 0, +e.g. zswap.same_filled_pages_enabled=0. It can also be enabled and disabled at +runtime using the sysfs "same_filled_pages_enabled" attribute, e.g. + +echo 1 > /sys/module/zswap/parameters/same_filled_pages_enabled + +When zswap same-filled page identification is disabled at runtime, it will stop +checking for the same-value filled pages during store operation. However, the +existing pages which are marked as same-value filled pages will be loaded or +invalidated. + A debugfs interface is provided for various statistic about pool size, number -of pages stored, and various counters for the reasons pages are rejected. +of pages stored, same-value filled pages and various counters for the reasons +pages are rejected. -- 2.7.4 -- 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:[~2017-11-29 15:34 UTC|newest] Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top [not found] <CGME20171018104832epcms5p1b2232e2236258de3d03d1344dde9fce0@epcms5p1> 2017-10-18 10:48 ` [PATCH] zswap: Same-filled pages handling Srividya Desireddy 2017-10-18 10:48 ` Srividya Desireddy 2017-10-18 12:34 ` Matthew Wilcox 2017-10-18 12:34 ` Matthew Wilcox 2017-10-18 13:33 ` Timofey Titovets 2017-10-18 13:33 ` Timofey Titovets 2017-10-18 14:11 ` Matthew Wilcox 2017-10-18 14:11 ` Matthew Wilcox 2017-10-18 20:43 ` Andi Kleen 2017-10-18 20:43 ` Andi Kleen 2017-10-19 1:10 ` Matthew Wilcox 2017-10-19 1:10 ` Matthew Wilcox 2017-10-19 4:30 ` Andi Kleen 2017-10-19 4:30 ` Andi Kleen 2017-10-19 13:24 ` Matthew Wilcox 2017-10-19 13:24 ` Matthew Wilcox 2017-10-18 21:31 ` Timofey Titovets 2017-10-18 21:31 ` Timofey Titovets 2017-10-19 1:08 ` Matthew Wilcox 2017-10-19 1:08 ` Matthew Wilcox [not found] ` <CGME20171018104832epcms5p1b2232e2236258de3d03d1344dde9fce0@epcms5p3> 2017-11-02 15:08 ` Srividya Desireddy 2017-11-02 15:08 ` Srividya Desireddy 2017-11-17 22:10 ` Dan Streetman 2017-11-17 22:10 ` Dan Streetman 2017-11-17 22:07 ` Dan Streetman 2017-11-17 22:07 ` Dan Streetman 2017-11-17 21:27 ` Dan Streetman 2017-11-17 21:27 ` Dan Streetman 2017-11-20 23:46 ` Andrew Morton 2017-11-20 23:46 ` Andrew Morton 2017-11-28 11:35 ` Dan Streetman 2017-11-28 11:35 ` Dan Streetman [not found] ` <CGME20171018104832epcms5p1b2232e2236258de3d03d1344dde9fce0@epcms5p6> 2017-11-29 15:34 ` Srividya Desireddy [this message] 2017-11-29 15:34 ` [PATCH] zswap: Update with same-value filled page feature Srividya Desireddy 2017-11-29 21:29 ` Dan Streetman 2017-11-29 21:29 ` Dan Streetman 2017-12-06 11:48 ` [PATCH v2] " Srividya Desireddy 2017-12-06 11:48 ` Srividya Desireddy 2017-12-06 15:20 ` Dan Streetman 2017-12-06 15:20 ` Dan Streetman [not found] ` <CGME20171018104832epcms5p1b2232e2236258de3d03d1344dde9fce0@epcms5p4> 2017-11-21 14:18 ` [PATCH v2] zswap: Same-filled pages handling Srividya Desireddy 2017-11-21 14:18 ` Srividya Desireddy 2017-10-18 14:43 ` [PATCH] " Srividya Desireddy 2017-10-18 14:43 ` Srividya Desireddy
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