From 5bc20fc59706214d9591c11e1938a629d3538c12 Mon Sep 17 00:00:00 2001 From: Dan Magenheimer Date: Thu, 26 May 2011 10:02:21 -0600 Subject: xen: cleancache shim to Xen Transcendent Memory This patch provides a shim between the kernel-internal cleancache API (see Documentation/mm/cleancache.txt) and the Xen Transcendent Memory ABI (see http://oss.oracle.com/projects/tmem). Xen tmem provides "hypervisor RAM" as an ephemeral page-oriented pseudo-RAM store for cleancache pages, shared cleancache pages, and frontswap pages. Tmem provides enterprise-quality concurrency, full save/restore and live migration support, compression and deduplication. A presentation showing up to 8% faster performance and up to 52% reduction in sectors read on a kernel compile workload, despite aggressive in-kernel page reclamation ("self-ballooning") can be found at: http://oss.oracle.com/projects/tmem/dist/documentation/presentations/TranscendentMemoryXenSummit2010.pdf Signed-off-by: Dan Magenheimer Reviewed-by: Jeremy Fitzhardinge Cc: Konrad Rzeszutek Wilk Cc: Matthew Wilcox Cc: Nick Piggin Cc: Mel Gorman Cc: Rik Van Riel Cc: Jan Beulich Cc: Chris Mason Cc: Andreas Dilger Cc: Ted Ts'o Cc: Mark Fasheh Cc: Joel Becker Cc: Nitin Gupta --- include/xen/interface/xen.h | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 'include/xen') diff --git a/include/xen/interface/xen.h b/include/xen/interface/xen.h index b33257bc7e83..70213b4515eb 100644 --- a/include/xen/interface/xen.h +++ b/include/xen/interface/xen.h @@ -58,6 +58,7 @@ #define __HYPERVISOR_event_channel_op 32 #define __HYPERVISOR_physdev_op 33 #define __HYPERVISOR_hvm_op 34 +#define __HYPERVISOR_tmem_op 38 /* Architecture-specific hypercall definitions. */ #define __HYPERVISOR_arch_0 48 @@ -461,6 +462,27 @@ typedef uint8_t xen_domain_handle_t[16]; #define __mk_unsigned_long(x) x ## UL #define mk_unsigned_long(x) __mk_unsigned_long(x) +#define TMEM_SPEC_VERSION 1 + +struct tmem_op { + uint32_t cmd; + int32_t pool_id; + union { + struct { /* for cmd == TMEM_NEW_POOL */ + uint64_t uuid[2]; + uint32_t flags; + } new; + struct { + uint64_t oid[3]; + uint32_t index; + uint32_t tmem_offset; + uint32_t pfn_offset; + uint32_t len; + GUEST_HANDLE(void) gmfn; /* guest machine page frame */ + } gen; + } u; +}; + #else /* __ASSEMBLY__ */ /* In assembly code we cannot use C numeric constant suffixes. */ -- cgit v1.2.3