summaryrefslogtreecommitdiff
path: root/Documentation/vm/frontswap.rst
diff options
context:
space:
mode:
authorChristoph Hellwig <hch@lst.de>2022-01-21 22:14:34 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2022-01-22 08:33:38 +0200
commit0a4ee518185e902758191d968600399f3bc2be31 (patch)
tree6bab9e953592626c4c0cf7ce6a4f7dd986421c4a /Documentation/vm/frontswap.rst
parente940066089490efde86abc519593be84362f4e53 (diff)
mm: remove cleancache
Patch series "remove Xen tmem leftovers". Since the removal of the Xen tmem driver in 2019, the cleancache hooks are entirely unused, as are large parts of frontswap. This series against linux-next (with the folio changes included) removes cleancaches, and cuts down frontswap to the bits actually used by zswap. This patch (of 13): The cleancache subsystem is unused since the removal of Xen tmem driver in commit 814bbf49dcd0 ("xen: remove tmem driver"). [akpm@linux-foundation.org: remove now-unreachable code] Link: https://lkml.kernel.org/r/20211224062246.1258487-1-hch@lst.de Link: https://lkml.kernel.org/r/20211224062246.1258487-2-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Juergen Gross <jgross@suse.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Konrad Rzeszutek Wilk <Konrad.wilk@oracle.com> Cc: Hugh Dickins <hughd@google.com> Cc: Seth Jennings <sjenning@redhat.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Vitaly Wool <vitaly.wool@konsulko.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation/vm/frontswap.rst')
-rw-r--r--Documentation/vm/frontswap.rst12
1 files changed, 2 insertions, 10 deletions
diff --git a/Documentation/vm/frontswap.rst b/Documentation/vm/frontswap.rst
index 1979f430c1c5..e2e5ab3e375e 100644
--- a/Documentation/vm/frontswap.rst
+++ b/Documentation/vm/frontswap.rst
@@ -8,12 +8,6 @@ Frontswap provides a "transcendent memory" interface for swap pages.
In some environments, dramatic performance savings may be obtained because
swapped pages are saved in RAM (or a RAM-like device) instead of a swap disk.
-(Note, frontswap -- and :ref:`cleancache` (merged at 3.0) -- are the "frontends"
-and the only necessary changes to the core kernel for transcendent memory;
-all other supporting code -- the "backends" -- is implemented as drivers.
-See the LWN.net article `Transcendent memory in a nutshell`_
-for a detailed overview of frontswap and related kernel parts)
-
.. _Transcendent memory in a nutshell: https://lwn.net/Articles/454795/
Frontswap is so named because it can be thought of as the opposite of
@@ -87,11 +81,9 @@ This interface is ideal when data is transformed to a different form
and size (such as with compression) or secretly moved (as might be
useful for write-balancing for some RAM-like devices). Swap pages (and
evicted page-cache pages) are a great use for this kind of slower-than-RAM-
-but-much-faster-than-disk "pseudo-RAM device" and the frontswap (and
-cleancache) interface to transcendent memory provides a nice way to read
-and write -- and indirectly "name" -- the pages.
+but-much-faster-than-disk "pseudo-RAM device".
-Frontswap -- and cleancache -- with a fairly small impact on the kernel,
+Frontswap with a fairly small impact on the kernel,
provides a huge amount of flexibility for more dynamic, flexible RAM
utilization in various system configurations: