#include "tests.h" #include "machine.h" #include "thread.h" #include "map.h" #include "debug.h" int test__thread_mg_share(int subtest __maybe_unused) { struct machines machines; struct machine *machine; /* thread group */ struct thread *leader; struct thread *t1, *t2, *t3; struct map_groups *mg; /* other process */ struct thread *other, *other_leader; struct map_groups *other_mg; /* * This test create 2 processes abstractions (struct thread) * with several threads and checks they properly share and * maintain map groups info (struct map_groups). * * thread group (pid: 0, tids: 0, 1, 2, 3) * other group (pid: 4, tids: 4, 5) */ machines__init(&machines); machine = &machines.host; /* create process with 4 threads */ leader = machine__findnew_thread(machine, 0, 0); t1 = machine__findnew_thread(machine, 0, 1); t2 = machine__findnew_thread(machine, 0, 2); t3 = machine__findnew_thread(machine, 0, 3); /* and create 1 separated process, without thread leader */ other = machine__findnew_thread(machine, 4, 5); TEST_ASSERT_VAL("failed to create threads", leader && t1 && t2 && t3 && other); mg = leader->mg; TEST_ASSERT_EQUAL("wrong refcnt", atomic_read(&mg->refcnt), 4); /* test the map groups pointer is shared */ TEST_ASSERT_VAL("map groups don't match", mg == t1->mg); TEST_ASSERT_VAL("map groups don't match", mg == t2->mg); TEST_ASSERT_VAL("map groups don't match", mg == t3->mg); /* * Verify the other leader was created by previous call. * It should have shared map groups with no change in * refcnt. */ other_leader = machine__find_thread(machine, 4, 4); TEST_ASSERT_VAL("failed to find other leader", other_leader); /* * Ok, now that all the rbtree related operations were done, * lets remove all of them from there so that we can do the * refcounting tests. */ machine__remove_thread(machine, leader); machine__remove_thread(machine, t1); machine__remove_thread(machine, t2); machine__remove_thread(machine, t3); machine__remove_thread(machine, other); machine__remove_thread(machine, other_leader); other_mg = other->mg; TEST_ASSERT_EQUAL("wrong refcnt", atomic_read(&other_mg->refcnt), 2); TEST_ASSERT_VAL("map groups don't match", other_mg == other_leader->mg); /* release thread group */ thread__put(leader); TEST_ASSERT_EQUAL("wrong refcnt", atomic_read(&mg->refcnt), 3); thread__put(t1); TEST_ASSERT_EQUAL("wrong refcnt", atomic_read(&mg->refcnt), 2); thread__put(t2); TEST_ASSERT_EQUAL("wrong refcnt", atomic_read(&mg->refcnt), 1); thread__put(t3); /* release other group */ thread__put(other_leader); TEST_ASSERT_EQUAL("wrong refcnt", atomic_read(&other_mg->refcnt), 1); thread__put(other); machines__exit(&machines); return 0; } aa534'>ipc/msgutil.c
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authorAruna Ramakrishna <aruna.ramakrishna@oracle.com>2016-10-27 17:46:32 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-10-27 18:43:43 -0700
commit07a63c41fa1f6533f5668e5b33a295bfd63aa534 (patch)
treebaccc737b4c09ce0abdc4bb0209ab9eccb2f9612 /ipc/msgutil.c
parent1f84a18fc010d7a62667199c9be35872bbf31526 (diff)
mm/slab: improve performance of gathering slabinfo stats
On large systems, when some slab caches grow to millions of objects (and many gigabytes), running 'cat /proc/slabinfo' can take up to 1-2 seconds. During this time, interrupts are disabled while walking the slab lists (slabs_full, slabs_partial, and slabs_free) for each node, and this sometimes causes timeouts in other drivers (for instance, Infiniband). This patch optimizes 'cat /proc/slabinfo' by maintaining a counter for total number of allocated slabs per node, per cache. This counter is updated when a slab is created or destroyed. This enables us to skip traversing the slabs_full list while gathering slabinfo statistics, and since slabs_full tends to be the biggest list when the cache is large, it results in a dramatic performance improvement. Getting slabinfo statistics now only requires walking the slabs_free and slabs_partial lists, and those lists are usually much smaller than slabs_full. We tested this after growing the dentry cache to 70GB, and the performance improved from 2s to 5ms. Link: http://lkml.kernel.org/r/1472517876-26814-1-git-send-email-aruna.ramakrishna@oracle.com Signed-off-by: Aruna Ramakrishna <aruna.ramakrishna@oracle.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'ipc/msgutil.c')