linux/include/xen/tmem.h

#ifndef _XEN_TMEM_H
#define _XEN_TMEM_H

#include <linux/types.h>

#ifdef CONFIG_XEN_TMEM_MODULE
#define tmem_enabled true
#else
/* defined in drivers/xen/tmem.c */
extern bool tmem_enabled;
#endif

#ifdef CONFIG_XEN_SELFBALLOONING
extern int xen_selfballoon_init(bool, bool);
#endif

#endif /* _XEN_TMEM_H */
xen: tmem: self-ballooning and frontswap-selfshrinking This patch introduces two in-kernel drivers for Xen transcendent memory ("tmem") functionality that complement cleancache and frontswap. Both use control theory to dynamically adjust and optimize memory utilization. Selfballooning controls the in-kernel Xen balloon driver, targeting a goal value (vm_committed_as), thus pushing less frequently used clean page cache pages (through the cleancache code) into Xen tmem where Xen can balance needs across all VMs residing on the physical machine. Frontswap-selfshrinking controls the number of pages in frontswap, driving it towards zero (effectively doing a partial swapoff) when in-kernel memory pressure subsides, freeing up RAM for other VMs. More detail is provided in the header comment of xen-selfballooning.c. Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com> [v8: konrad.wilk@oracle.com: set default enablement depending on frontswap] [v7: konrad.wilk@oracle.com: fix capitalization and punctuation in comments] [v6: fix frontswap-selfshrinking initialization] [v6: konrad.wilk@oracle.com: fix init pr_infos; add comments about swap] [v5: konrad.wilk@oracle.com: add NULL to attr list; move inits up to decls] [v4: dkiper@net-space.pl: use strict_strtoul plus a few syntactic nits] [v3: konrad.wilk@oracle.com: fix potential divides-by-zero] [v3: konrad.wilk@oracle.com: add many more comments, fix nits] [v2: rebased to linux-3.0-rc1] [v2: Ian.Campbell@citrix.com: reorganize as new file (xen-selfballoon.c)] [v2: dkiper@net-space.pl: proper access to vm_committed_as] [v2: dkiper@net-space.pl: accounting fixes] Cc: Jan Beulich <JBeulich@novell.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: <xen-devel@lists.xensource.com> 2011-07-08 22:26:21 +04:00			`#ifndef _XEN_TMEM_H`
			`#define _XEN_TMEM_H`
xen/tmem: cleanup Use 'bool' for boolean variables. Do proper section placement. Eliminate an unnecessary export. Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> 2012-02-03 19:09:04 +04:00
			`#include <linux/types.h>`

xen: tmem: enable Xen tmem shim to be built/loaded as a module Allow Xen tmem shim to be built/loaded as a module. Xen self-ballooning and frontswap-selfshrinking are now also "lazily" initialized when the Xen tmem shim is loaded as a module, unless explicitly disabled by module parameters. Note runtime dependency disallows loading if cleancache/frontswap lazy initialization patches are not present. If built-in (not built as a module), the original mechanism of enabling via a kernel boot parameter is retained, but this should be considered deprecated. Note that module unload is explicitly not yet supported. [v1: Removed the [CLEANCACHE\|FRONTSWAP]_HAS_LAZY_INIT ifdef] [v2: Squashed the xen/tmem: Remove the subsys call patch in] [akpm@linux-foundation.org: fix build (disable_frontswap_selfshrinking undeclared)] Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Bob Liu <lliubbo@gmail.com> Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Andor Daam <andor.daam@googlemail.com> Cc: Florian Schmaus <fschmaus@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Stefan Hengelein <ilendir@googlemail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 2013-05-01 02:27:00 +04:00			`#ifdef CONFIG_XEN_TMEM_MODULE`
			`#define tmem_enabled true`
			`#else`
xen: tmem: self-ballooning and frontswap-selfshrinking This patch introduces two in-kernel drivers for Xen transcendent memory ("tmem") functionality that complement cleancache and frontswap. Both use control theory to dynamically adjust and optimize memory utilization. Selfballooning controls the in-kernel Xen balloon driver, targeting a goal value (vm_committed_as), thus pushing less frequently used clean page cache pages (through the cleancache code) into Xen tmem where Xen can balance needs across all VMs residing on the physical machine. Frontswap-selfshrinking controls the number of pages in frontswap, driving it towards zero (effectively doing a partial swapoff) when in-kernel memory pressure subsides, freeing up RAM for other VMs. More detail is provided in the header comment of xen-selfballooning.c. Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com> [v8: konrad.wilk@oracle.com: set default enablement depending on frontswap] [v7: konrad.wilk@oracle.com: fix capitalization and punctuation in comments] [v6: fix frontswap-selfshrinking initialization] [v6: konrad.wilk@oracle.com: fix init pr_infos; add comments about swap] [v5: konrad.wilk@oracle.com: add NULL to attr list; move inits up to decls] [v4: dkiper@net-space.pl: use strict_strtoul plus a few syntactic nits] [v3: konrad.wilk@oracle.com: fix potential divides-by-zero] [v3: konrad.wilk@oracle.com: add many more comments, fix nits] [v2: rebased to linux-3.0-rc1] [v2: Ian.Campbell@citrix.com: reorganize as new file (xen-selfballoon.c)] [v2: dkiper@net-space.pl: proper access to vm_committed_as] [v2: dkiper@net-space.pl: accounting fixes] Cc: Jan Beulich <JBeulich@novell.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: <xen-devel@lists.xensource.com> 2011-07-08 22:26:21 +04:00			`/* defined in drivers/xen/tmem.c */`
xen/tmem: cleanup Use 'bool' for boolean variables. Do proper section placement. Eliminate an unnecessary export. Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> 2012-02-03 19:09:04 +04:00			`extern bool tmem_enabled;`
xen: tmem: enable Xen tmem shim to be built/loaded as a module Allow Xen tmem shim to be built/loaded as a module. Xen self-ballooning and frontswap-selfshrinking are now also "lazily" initialized when the Xen tmem shim is loaded as a module, unless explicitly disabled by module parameters. Note runtime dependency disallows loading if cleancache/frontswap lazy initialization patches are not present. If built-in (not built as a module), the original mechanism of enabling via a kernel boot parameter is retained, but this should be considered deprecated. Note that module unload is explicitly not yet supported. [v1: Removed the [CLEANCACHE\|FRONTSWAP]_HAS_LAZY_INIT ifdef] [v2: Squashed the xen/tmem: Remove the subsys call patch in] [akpm@linux-foundation.org: fix build (disable_frontswap_selfshrinking undeclared)] Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Bob Liu <lliubbo@gmail.com> Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Andor Daam <andor.daam@googlemail.com> Cc: Florian Schmaus <fschmaus@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Stefan Hengelein <ilendir@googlemail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 2013-05-01 02:27:00 +04:00			`#endif`

			`#ifdef CONFIG_XEN_SELFBALLOONING`
			`extern int xen_selfballoon_init(bool, bool);`
			`#endif`
xen/tmem: cleanup Use 'bool' for boolean variables. Do proper section placement. Eliminate an unnecessary export. Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> 2012-02-03 19:09:04 +04:00
xen: tmem: self-ballooning and frontswap-selfshrinking This patch introduces two in-kernel drivers for Xen transcendent memory ("tmem") functionality that complement cleancache and frontswap. Both use control theory to dynamically adjust and optimize memory utilization. Selfballooning controls the in-kernel Xen balloon driver, targeting a goal value (vm_committed_as), thus pushing less frequently used clean page cache pages (through the cleancache code) into Xen tmem where Xen can balance needs across all VMs residing on the physical machine. Frontswap-selfshrinking controls the number of pages in frontswap, driving it towards zero (effectively doing a partial swapoff) when in-kernel memory pressure subsides, freeing up RAM for other VMs. More detail is provided in the header comment of xen-selfballooning.c. Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com> [v8: konrad.wilk@oracle.com: set default enablement depending on frontswap] [v7: konrad.wilk@oracle.com: fix capitalization and punctuation in comments] [v6: fix frontswap-selfshrinking initialization] [v6: konrad.wilk@oracle.com: fix init pr_infos; add comments about swap] [v5: konrad.wilk@oracle.com: add NULL to attr list; move inits up to decls] [v4: dkiper@net-space.pl: use strict_strtoul plus a few syntactic nits] [v3: konrad.wilk@oracle.com: fix potential divides-by-zero] [v3: konrad.wilk@oracle.com: add many more comments, fix nits] [v2: rebased to linux-3.0-rc1] [v2: Ian.Campbell@citrix.com: reorganize as new file (xen-selfballoon.c)] [v2: dkiper@net-space.pl: proper access to vm_committed_as] [v2: dkiper@net-space.pl: accounting fixes] Cc: Jan Beulich <JBeulich@novell.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: <xen-devel@lists.xensource.com> 2011-07-08 22:26:21 +04:00			`#endif /* _XEN_TMEM_H */`