From: Sergey Senozhatsky <senozhatsky@chromium.org>
To: Andrew Morton <akpm@linux-foundation.org>,
Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Sergey Senozhatsky <senozhatsky@chromium.org>
Subject: [PATCHv4 8/9] Documentation: document zram pages_per_pool_page attribute
Date: Mon, 31 Oct 2022 14:41:07 +0900 [thread overview]
Message-ID: <20221031054108.541190-9-senozhatsky@chromium.org> (raw)
In-Reply-To: <20221031054108.541190-1-senozhatsky@chromium.org>
Provide a simple documentation for pages_per_pool_page ZRAM
device attribute.
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
---
Documentation/admin-guide/blockdev/zram.rst | 38 ++++++++++++++++-----
1 file changed, 30 insertions(+), 8 deletions(-)
diff --git a/Documentation/admin-guide/blockdev/zram.rst b/Documentation/admin-guide/blockdev/zram.rst
index 010fb05a5999..4cb287520d45 100644
--- a/Documentation/admin-guide/blockdev/zram.rst
+++ b/Documentation/admin-guide/blockdev/zram.rst
@@ -112,7 +112,29 @@ to list all of them using, for instance, /proc/crypto or any other
method. This, however, has an advantage of permitting the usage of
custom crypto compression modules (implementing S/W or H/W compression).
-4) Set Disksize
+4) Set pages per-pool page limit: Optional
+==========================================
+
+zsmalloc pages can consist of up to ZS_DEFAULT_PAGES_PER_ZSPAGE (single)
+physical pages. The exact number is calculated for each zsmalloc size
+class during zsmalloc pool creation. ZRAM provides pages_per_pool_page
+device attribute that lets one adjust that limit (maximum possible value
+is ZS_MAX_PAGES_PER_ZSPAGE). The default limit is considered to be good
+enough, so tweak this value only when the changes in zsmalloc size classes
+characteristics are beneficial for your data patterns. The limit on the
+pages per zspages (currently) should be in [1,16] range; default value
+is 4.
+
+Examples::
+
+ #show current zsmalloc pages per-pool page limit
+ cat /sys/block/zramX/pages_per_pool_page
+ 4
+
+ #set zsmalloc pages per-pool page limit
+ echo 8 > /sys/block/zramX/pages_per_pool_page
+
+5) Set Disksize
===============
Set disk size by writing the value to sysfs node 'disksize'.
@@ -132,7 +154,7 @@ There is little point creating a zram of greater than twice the size of memory
since we expect a 2:1 compression ratio. Note that zram uses about 0.1% of the
size of the disk when not in use so a huge zram is wasteful.
-5) Set memory limit: Optional
+6) Set memory limit: Optional
=============================
Set memory limit by writing the value to sysfs node 'mem_limit'.
@@ -151,7 +173,7 @@ Examples::
# To disable memory limit
echo 0 > /sys/block/zram0/mem_limit
-6) Activate
+7) Activate
===========
::
@@ -162,7 +184,7 @@ Examples::
mkfs.ext4 /dev/zram1
mount /dev/zram1 /tmp
-7) Add/remove zram devices
+8) Add/remove zram devices
==========================
zram provides a control interface, which enables dynamic (on-demand) device
@@ -182,7 +204,7 @@ execute::
echo X > /sys/class/zram-control/hot_remove
-8) Stats
+9) Stats
========
Per-device statistics are exported as various nodes under /sys/block/zram<id>/
@@ -283,15 +305,15 @@ a single line of text and contains the following stats separated by whitespace:
Unit: 4K bytes
============== =============================================================
-9) Deactivate
-=============
+10) Deactivate
+==============
::
swapoff /dev/zram0
umount /dev/zram1
-10) Reset
+11) Reset
=========
Write any positive value to 'reset' sysfs node::
--
2.38.1.273.g43a17bfeac-goog
next prev parent reply other threads:[~2022-10-31 5:42 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-31 5:40 [PATCHv4 0/9] zsmalloc/zram: configurable zspage size Sergey Senozhatsky
2022-10-31 5:41 ` [PATCHv4 1/9] zram: add size class equals check into recompression Sergey Senozhatsky
2022-10-31 5:41 ` [PATCHv4 2/9] zsmalloc: turn zspage order into runtime variable Sergey Senozhatsky
2022-11-10 21:59 ` Minchan Kim
2022-11-11 10:38 ` Sergey Senozhatsky
2022-11-11 17:09 ` Minchan Kim
2022-11-14 3:55 ` Sergey Senozhatsky
2022-10-31 5:41 ` [PATCHv4 3/9] zsmalloc: move away from page order defines Sergey Senozhatsky
2022-11-10 22:02 ` Minchan Kim
2022-10-31 5:41 ` [PATCHv4 4/9] zsmalloc: make huge class watermark zs_pool member Sergey Senozhatsky
2022-11-10 22:25 ` Minchan Kim
2022-11-11 1:07 ` Sergey Senozhatsky
2022-10-31 5:41 ` [PATCHv4 5/9] zram: huge size watermark cannot be global Sergey Senozhatsky
2022-10-31 5:41 ` [PATCHv4 6/9] zsmalloc: pass limit on pages per-zspage to zs_create_pool() Sergey Senozhatsky
2022-11-09 6:24 ` Sergey Senozhatsky
2022-11-11 17:14 ` Minchan Kim
2022-11-11 2:10 ` Minchan Kim
2022-11-11 10:32 ` Sergey Senozhatsky
2022-10-31 5:41 ` [PATCHv4 7/9] zram: add pages_per_pool_page device attribute Sergey Senozhatsky
2022-11-09 4:34 ` Sergey Senozhatsky
2022-10-31 5:41 ` Sergey Senozhatsky [this message]
2022-11-11 2:20 ` [PATCHv4 8/9] Documentation: document zram pages_per_pool_page attribute Minchan Kim
2022-11-11 10:34 ` Sergey Senozhatsky
2022-10-31 5:41 ` [PATCHv4 9/9] zsmalloc: break out of loop when found perfect zspage order Sergey Senozhatsky
2022-11-10 22:44 ` [PATCHv4 0/9] zsmalloc/zram: configurable zspage size Minchan Kim
2022-11-11 0:56 ` Sergey Senozhatsky
2022-11-11 17:03 ` Minchan Kim
2022-11-14 3:53 ` Sergey Senozhatsky
2022-11-14 7:55 ` Sergey Senozhatsky
2022-11-14 8:37 ` Sergey Senozhatsky
2022-11-15 6:01 ` Sergey Senozhatsky
2022-11-15 7:59 ` Sergey Senozhatsky
2022-11-15 23:23 ` Minchan Kim
2022-11-16 0:52 ` Sergey Senozhatsky
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