user/sven/linux.git/include/linux/mempolicy.h, branch v3.16.46

hugetlb: restrict hugepage_migration_support() to x86_64

2014-06-04T23:53:51Z

Currently hugepage migration is available for all archs which support pmd-level hugepage, but testing is done only for x86_64 and there're bugs for other archs. So to avoid breaking such archs, this patch limits the availability strictly to x86_64 until developers of other archs get interested in enabling this feature. Simply disabling hugepage migration on non-x86_64 archs is not enough to fix the reported problem where sys_move_pages() hits the BUG_ON() in follow_page(FOLL_GET), so let's fix this by checking if hugepage migration is supported in vma_migratable(). Signed-off-by: Naoya Horiguchi Reported-by: Michael Ellerman Tested-by: Michael Ellerman Acked-by: Hugh Dickins Cc: Benjamin Herrenschmidt Cc: Tony Luck Cc: Russell King Cc: Martin Schwidefsky Cc: James Hogan Cc: Ralf Baechle Cc: David Miller Cc: [3.12+] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm, mempolicy: remove per-process flag

2014-04-07T23:35:54Z

PF_MEMPOLICY is an unnecessary optimization for CONFIG_SLAB users. There's no significant performance degradation to checking current->mempolicy rather than current->flags & PF_MEMPOLICY in the allocation path, especially since this is considered unlikely(). Running TCP_RR with netperf-2.4.5 through localhost on 16 cpu machine with 64GB of memory and without a mempolicy: threads before after 16 1249409 1244487 32 1281786 1246783 48 1239175 1239138 64 1244642 1241841 80 1244346 1248918 96 1266436 1254316 112 1307398 1312135 128 1327607 1326502 Per-process flags are a scarce resource so we should free them up whenever possible and make them available. We'll be using it shortly for memcg oom reserves. Signed-off-by: David Rientjes Cc: Johannes Weiner Cc: Michal Hocko Cc: KAMEZAWA Hiroyuki Cc: Christoph Lameter Cc: Pekka Enberg Cc: Tejun Heo Cc: Mel Gorman Cc: Oleg Nesterov Cc: Rik van Riel Cc: Jianguo Wu Cc: Tim Hockin Cc: Christoph Lameter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm, mempolicy: rename slab_node for clarity

2014-04-07T23:35:54Z

slab_node() is actually a mempolicy function, so rename it to mempolicy_slab_node() to make it clearer that it used for processes with mempolicies. At the same time, cleanup its code by saving numa_mem_id() in a local variable (since we require a node with memory, not just any node) and remove an obsolete comment that assumes the mempolicy is actually passed into the function. Signed-off-by: David Rientjes Acked-by: Christoph Lameter Cc: Johannes Weiner Cc: Michal Hocko Cc: KAMEZAWA Hiroyuki Cc: Christoph Lameter Cc: Pekka Enberg Cc: Tejun Heo Cc: Mel Gorman Cc: Oleg Nesterov Cc: Rik van Riel Cc: Jianguo Wu Cc: Tim Hockin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm, mempolicy: remove unneeded functions for UMA configs

2014-01-22T00:19:44Z

Mempolicies only exist for CONFIG_NUMA configurations. Therefore, a certain class of functions are unneeded in configurations where CONFIG_NUMA is disabled such as functions that duplicate existing mempolicies, lookup existing policies, set certain mempolicy traits, or test mempolicies for certain attributes. Remove the unneeded functions so that any future callers get a compile- time error and protect their code with CONFIG_NUMA as required. Signed-off-by: David Rientjes Cc: KOSAKI Motohiro Cc: Johannes Weiner Cc: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm, mempolicy: make mpol_to_str robust and always succeed

2013-11-13T03:09:05Z

mpol_to_str() should not fail. Currently, it either fails because the string buffer is too small or because a string hasn't been defined for a mempolicy mode. If a new mempolicy mode is introduced and no string is defined for it, just warn and return "unknown". If the buffer is too small, just truncate the string and return, the same behavior as snprintf(). This also fixes a bug where there was no NULL-byte termination when doing *p++ = '=' and *p++ ':' and maxlen has been reached. Signed-off-by: David Rientjes Cc: KOSAKI Motohiro Cc: Chen Gang Cc: Rik van Riel Cc: Dave Jones Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: numa: Limit NUMA scanning to migrate-on-fault VMAs

2013-10-09T10:40:38Z

There is a 90% regression observed with a large Oracle performance test on a 4 node system. Profiles indicated that the overhead was due to contention on sp_lock when looking up shared memory policies. These policies do not have the appropriate flags to allow them to be automatically balanced so trapping faults on them is pointless. This patch skips VMAs that do not have MPOL_F_MOF set. [riel@redhat.com: Initial patch] Signed-off-by: Mel Gorman Reported-and-tested-by: Joe Mario Reviewed-by: Rik van Riel Cc: Andrea Arcangeli Cc: Johannes Weiner Cc: Srikar Dronamraju Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1381141781-10992-32-git-send-email-mgorman@suse.de Signed-off-by: Ingo Molnar

mm: migrate: remove VM_HUGETLB from vma flag check in vma_migratable()

2013-09-11T22:57:48Z

Enable hugepage migration from migrate_pages(2), move_pages(2), and mbind(2). Signed-off-by: Naoya Horiguchi Acked-by: Hillf Danton Acked-by: Andi Kleen Reviewed-by: Wanpeng Li Cc: Mel Gorman Cc: Hugh Dickins Cc: KOSAKI Motohiro Cc: Michal Hocko Cc: Rik van Riel Cc: "Aneesh Kumar K.V" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: mempolicy: turn vma_set_policy() into vma_dup_policy()

2013-09-11T22:57:00Z

Simple cleanup. Every user of vma_set_policy() does the same work, this looks a bit annoying imho. And the new trivial helper which does mpol_dup() + vma_set_policy() to simplify the callers. Signed-off-by: Oleg Nesterov Cc: KOSAKI Motohiro Cc: Mel Gorman Cc: Rik van Riel Cc: Andi Kleen Cc: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: mempolicy: Convert shared_policy mutex to spinlock

2013-01-03T01:32:13Z

Sasha was fuzzing with trinity and reported the following problem: BUG: sleeping function called from invalid context at kernel/mutex.c:269 in_atomic(): 1, irqs_disabled(): 0, pid: 6361, name: trinity-main 2 locks held by trinity-main/6361: #0: (&mm->mmap_sem){++++++}, at: [] __do_page_fault+0x1e4/0x4f0 #1: (&(&mm->page_table_lock)->rlock){+.+...}, at: [] handle_pte_fault+0x3f7/0x6a0 Pid: 6361, comm: trinity-main Tainted: G W 3.7.0-rc2-next-20121024-sasha-00001-gd95ef01-dirty #74 Call Trace: __might_sleep+0x1c3/0x1e0 mutex_lock_nested+0x29/0x50 mpol_shared_policy_lookup+0x2e/0x90 shmem_get_policy+0x2e/0x30 get_vma_policy+0x5a/0xa0 mpol_misplaced+0x41/0x1d0 handle_pte_fault+0x465/0x6a0 This was triggered by a different version of automatic NUMA balancing but in theory the current version is vunerable to the same problem. do_numa_page -> numa_migrate_prep -> mpol_misplaced -> get_vma_policy -> shmem_get_policy It's very unlikely this will happen as shared pages are not marked pte_numa -- see the page_mapcount() check in change_pte_range() -- but it is possible. To address this, this patch restores sp->lock as originally implemented by Kosaki Motohiro. In the path where get_vma_policy() is called, it should not be calling sp_alloc() so it is not necessary to treat the PTL specially. Signed-off-by: KOSAKI Motohiro Tested-by: KOSAKI Motohiro Signed-off-by: Mel Gorman Signed-off-by: Linus Torvalds

mempolicy: remove arg from mpol_parse_str, mpol_to_str

2013-01-02T17:27:10Z

Remove the unused argument (formerly no_context) from mpol_parse_str() and from mpol_to_str(). Signed-off-by: Hugh Dickins Signed-off-by: Linus Torvalds