From 479e2802d09f1e18a97262c4c6f8f17ae5884bd8 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 25 Oct 2012 14:16:28 +0200 Subject: mm: mempolicy: Make MPOL_LOCAL a real policy Make MPOL_LOCAL a real and exposed policy such that applications that relied on the previous default behaviour can explicitly request it. Requested-by: Christoph Lameter Reviewed-by: Rik van Riel Cc: Lee Schermerhorn Cc: Andrew Morton Cc: Linus Torvalds Signed-off-by: Peter Zijlstra Signed-off-by: Ingo Molnar Signed-off-by: Mel Gorman --- include/uapi/linux/mempolicy.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/uapi') diff --git a/include/uapi/linux/mempolicy.h b/include/uapi/linux/mempolicy.h index 23e62e0537e2..3e835c9d847b 100644 --- a/include/uapi/linux/mempolicy.h +++ b/include/uapi/linux/mempolicy.h @@ -20,6 +20,7 @@ enum { MPOL_PREFERRED, MPOL_BIND, MPOL_INTERLEAVE, + MPOL_LOCAL, MPOL_MAX, /* always last member of enum */ }; -- cgit v1.2.3 From d3a710337b0590f43fd236d5e6518439afc7410a Mon Sep 17 00:00:00 2001 From: Lee Schermerhorn Date: Thu, 25 Oct 2012 14:16:29 +0200 Subject: mm: mempolicy: Add MPOL_NOOP This patch augments the MPOL_MF_LAZY feature by adding a "NOOP" policy to mbind(). When the NOOP policy is used with the 'MOVE and 'LAZY flags, mbind() will map the pages PROT_NONE so that they will be migrated on the next touch. This allows an application to prepare for a new phase of operation where different regions of shared storage will be assigned to worker threads, w/o changing policy. Note that we could just use "default" policy in this case. However, this also allows an application to request that pages be migrated, only if necessary, to follow any arbitrary policy that might currently apply to a range of pages, without knowing the policy, or without specifying multiple mbind()s for ranges with different policies. [ Bug in early version of mpol_parse_str() reported by Fengguang Wu. ] Bug-Reported-by: Reported-by: Fengguang Wu Signed-off-by: Lee Schermerhorn Reviewed-by: Rik van Riel Cc: Andrew Morton Cc: Linus Torvalds Signed-off-by: Peter Zijlstra Signed-off-by: Ingo Molnar Signed-off-by: Mel Gorman --- include/uapi/linux/mempolicy.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/uapi') diff --git a/include/uapi/linux/mempolicy.h b/include/uapi/linux/mempolicy.h index 3e835c9d847b..d23dca8367cc 100644 --- a/include/uapi/linux/mempolicy.h +++ b/include/uapi/linux/mempolicy.h @@ -21,6 +21,7 @@ enum { MPOL_BIND, MPOL_INTERLEAVE, MPOL_LOCAL, + MPOL_NOOP, /* retain existing policy for range */ MPOL_MAX, /* always last member of enum */ }; -- cgit v1.2.3 From 771fb4d806a92bf6c988fcfbd286ae40a9374332 Mon Sep 17 00:00:00 2001 From: Lee Schermerhorn Date: Thu, 25 Oct 2012 14:16:30 +0200 Subject: mm: mempolicy: Check for misplaced page This patch provides a new function to test whether a page resides on a node that is appropriate for the mempolicy for the vma and address where the page is supposed to be mapped. This involves looking up the node where the page belongs. So, the function returns that node so that it may be used to allocated the page without consulting the policy again. A subsequent patch will call this function from the fault path. Because of this, I don't want to go ahead and allocate the page, e.g., via alloc_page_vma() only to have to free it if it has the correct policy. So, I just mimic the alloc_page_vma() node computation logic--sort of. Note: we could use this function to implement a MPOL_MF_STRICT behavior when migrating pages to match mbind() mempolicy--e.g., to ensure that pages in an interleaved range are reinterleaved rather than left where they are when they reside on any page in the interleave nodemask. Signed-off-by: Lee Schermerhorn Reviewed-by: Rik van Riel Cc: Andrew Morton Cc: Linus Torvalds [ Added MPOL_F_LAZY to trigger migrate-on-fault; simplified code now that we don't have to bother with special crap for interleaved ] Signed-off-by: Peter Zijlstra Signed-off-by: Ingo Molnar Signed-off-by: Mel Gorman --- include/uapi/linux/mempolicy.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/uapi') diff --git a/include/uapi/linux/mempolicy.h b/include/uapi/linux/mempolicy.h index d23dca8367cc..472de8a5d37e 100644 --- a/include/uapi/linux/mempolicy.h +++ b/include/uapi/linux/mempolicy.h @@ -61,6 +61,7 @@ enum mpol_rebind_step { #define MPOL_F_SHARED (1 << 0) /* identify shared policies */ #define MPOL_F_LOCAL (1 << 1) /* preferred local allocation */ #define MPOL_F_REBINDING (1 << 2) /* identify policies in rebinding */ +#define MPOL_F_MOF (1 << 3) /* this policy wants migrate on fault */ #endif /* _UAPI_LINUX_MEMPOLICY_H */ -- cgit v1.2.3 From b24f53a0bea38b266d219ee651b22dba727c44ae Mon Sep 17 00:00:00 2001 From: Lee Schermerhorn Date: Thu, 25 Oct 2012 14:16:32 +0200 Subject: mm: mempolicy: Add MPOL_MF_LAZY NOTE: Once again there is a lot of patch stealing and the end result is sufficiently different that I had to drop the signed-offs. Will re-add if the original authors are ok with that. This patch adds another mbind() flag to request "lazy migration". The flag, MPOL_MF_LAZY, modifies MPOL_MF_MOVE* such that the selected pages are marked PROT_NONE. The pages will be migrated in the fault path on "first touch", if the policy dictates at that time. "Lazy Migration" will allow testing of migrate-on-fault via mbind(). Also allows applications to specify that only subsequently touched pages be migrated to obey new policy, instead of all pages in range. This can be useful for multi-threaded applications working on a large shared data area that is initialized by an initial thread resulting in all pages on one [or a few, if overflowed] nodes. After PROT_NONE, the pages in regions assigned to the worker threads will be automatically migrated local to the threads on 1st touch. Signed-off-by: Mel Gorman Reviewed-by: Rik van Riel --- include/uapi/linux/mempolicy.h | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) (limited to 'include/uapi') diff --git a/include/uapi/linux/mempolicy.h b/include/uapi/linux/mempolicy.h index 472de8a5d37e..6a1baae3775d 100644 --- a/include/uapi/linux/mempolicy.h +++ b/include/uapi/linux/mempolicy.h @@ -49,9 +49,16 @@ enum mpol_rebind_step { /* Flags for mbind */ #define MPOL_MF_STRICT (1<<0) /* Verify existing pages in the mapping */ -#define MPOL_MF_MOVE (1<<1) /* Move pages owned by this process to conform to mapping */ -#define MPOL_MF_MOVE_ALL (1<<2) /* Move every page to conform to mapping */ -#define MPOL_MF_INTERNAL (1<<3) /* Internal flags start here */ +#define MPOL_MF_MOVE (1<<1) /* Move pages owned by this process to conform + to policy */ +#define MPOL_MF_MOVE_ALL (1<<2) /* Move every page to conform to policy */ +#define MPOL_MF_LAZY (1<<3) /* Modifies '_MOVE: lazy migrate on fault */ +#define MPOL_MF_INTERNAL (1<<4) /* Internal flags start here */ + +#define MPOL_MF_VALID (MPOL_MF_STRICT | \ + MPOL_MF_MOVE | \ + MPOL_MF_MOVE_ALL | \ + MPOL_MF_LAZY) /* * Internal flags that share the struct mempolicy flags word with -- cgit v1.2.3 From a720094ded8cbb303111035be91858011d2eac71 Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Fri, 16 Nov 2012 09:37:58 +0000 Subject: mm: mempolicy: Hide MPOL_NOOP and MPOL_MF_LAZY from userspace for now The use of MPOL_NOOP and MPOL_MF_LAZY to allow an application to explicitly request lazy migration is a good idea but the actual API has not been well reviewed and once released we have to support it. For now this patch prevents an application using the services. This will need to be revisited. Signed-off-by: Mel Gorman --- include/uapi/linux/mempolicy.h | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'include/uapi') diff --git a/include/uapi/linux/mempolicy.h b/include/uapi/linux/mempolicy.h index 6a1baae3775d..16fb4e6efbc4 100644 --- a/include/uapi/linux/mempolicy.h +++ b/include/uapi/linux/mempolicy.h @@ -21,7 +21,6 @@ enum { MPOL_BIND, MPOL_INTERLEAVE, MPOL_LOCAL, - MPOL_NOOP, /* retain existing policy for range */ MPOL_MAX, /* always last member of enum */ }; @@ -57,8 +56,7 @@ enum mpol_rebind_step { #define MPOL_MF_VALID (MPOL_MF_STRICT | \ MPOL_MF_MOVE | \ - MPOL_MF_MOVE_ALL | \ - MPOL_MF_LAZY) + MPOL_MF_MOVE_ALL) /* * Internal flags that share the struct mempolicy flags word with -- cgit v1.2.3 From 5606e3877ad8baea42f3a71ebde0a03622bbb551 Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Fri, 2 Nov 2012 18:19:13 +0000 Subject: mm: numa: Migrate on reference policy This is the simplest possible policy that still does something of note. When a pte_numa is faulted, it is moved immediately. Any replacement policy must at least do better than this and in all likelihood this policy regresses normal workloads. Signed-off-by: Mel Gorman Acked-by: Rik van Riel --- include/uapi/linux/mempolicy.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/uapi') diff --git a/include/uapi/linux/mempolicy.h b/include/uapi/linux/mempolicy.h index 16fb4e6efbc4..0d11c3dcd3a1 100644 --- a/include/uapi/linux/mempolicy.h +++ b/include/uapi/linux/mempolicy.h @@ -67,6 +67,7 @@ enum mpol_rebind_step { #define MPOL_F_LOCAL (1 << 1) /* preferred local allocation */ #define MPOL_F_REBINDING (1 << 2) /* identify policies in rebinding */ #define MPOL_F_MOF (1 << 3) /* this policy wants migrate on fault */ +#define MPOL_F_MORON (1 << 4) /* Migrate On pte_numa Reference On Node */ #endif /* _UAPI_LINUX_MEMPOLICY_H */ -- cgit v1.2.3