admin-guide/mm/zswap.rst

10 dynamically allocated RAM-based memory pool.  zswap basically trades CPU cycles
11 for potentially reduced swap I/O.  This trade-off can also result in a
24   drastically reducing life-shortening writes.
30 Whether Zswap is enabled at the boot time depends on whether
31 the ``CONFIG_ZSWAP_DEFAULT_ON`` Kconfig option is enabled or not.
33 ``zswap.enabled=`` option, for example ``zswap.enabled=0``.
34 Zswap can also be enabled and disabled at runtime using the sysfs interface.
38 	echo 1 > /sys/module/zswap/parameters/enabled
62 but it can be overridden at boot time by setting the ``zpool`` attribute,
69 means the compression ratio will always be 2:1 or worse (because of half-full
76 with a red-black tree per swap type.  The swap offset is the search key for the
90 * max_pool_percent - The maximum percentage of memory that the compressed
94 Kconfig option, but it can be overridden at boot time by setting the
107 Some of the pages in zswap are same-value filled pages (i.e. contents of the
108 page have same value or repetitive pattern). These pages include zero-filled
110 checked if it is a same-value filled page before compressing it. If true, the
111 compressed length of the page is set to zero and the pattern or same-filled
129 zswap itself) on a cgroup-basis as follows::
131 	echo 0 > /sys/fs/cgroup/<cgroup-name>/memory.zswap.writeback
144 This can be enabled at the boot time if ``CONFIG_ZSWAP_SHRINKER_DEFAULT_ON`` is
148 of pages stored, same-value filled pages and various counters for the reasons