From: Roman Gushchin <guro@fb.com>
To: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Johannes Weiner <hannes@cmpxchg.org>,
Michal Hocko <mhocko@kernel.org>, <linux-mm@kvack.org>,
<kernel-team@fb.com>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v3 18/19] kselftests: cgroup: add kernel memory accounting tests
Date: Tue, 26 May 2020 08:45:08 -0700 [thread overview]
Message-ID: <20200526154508.GA364753@carbon.DHCP.thefacebook.com> (raw)
In-Reply-To: <d980935c-fecc-9682-7dab-bdcf33c12a9c@suse.cz>
On Tue, May 26, 2020 at 05:24:46PM +0200, Vlastimil Babka wrote:
> On 4/22/20 10:47 PM, Roman Gushchin wrote:
> > Add some tests to cover the kernel memory accounting functionality.
> > These are covering some issues (and changes) we had recently.
> >
> > 1) A test which allocates a lot of negative dentries, checks memcg
> > slab statistics, creates memory pressure by setting memory.max
> > to some low value and checks that some number of slabs was reclaimed.
> >
> > 2) A test which covers side effects of memcg destruction: it creates
> > and destroys a large number of sub-cgroups, each containing a
> > multi-threaded workload which allocates and releases some kernel
> > memory. Then it checks that the charge ans memory.stats do add up
> > on the parent level.
> >
> > 3) A test which reads /proc/kpagecgroup and implicitly checks that it
> > doesn't crash the system.
> >
> > 4) A test which spawns a large number of threads and checks that
> > the kernel stacks accounting works as expected.
> >
> > 5) A test which checks that living charged slab objects are not
> > preventing the memory cgroup from being released after being deleted
> > by a user.
> >
> > Signed-off-by: Roman Gushchin <guro@fb.com>
> > ---
> > tools/testing/selftests/cgroup/.gitignore | 1 +
> > tools/testing/selftests/cgroup/Makefile | 2 +
> > tools/testing/selftests/cgroup/test_kmem.c | 382 +++++++++++++++++++++
> > 3 files changed, 385 insertions(+)
> > create mode 100644 tools/testing/selftests/cgroup/test_kmem.c
> >
> > diff --git a/tools/testing/selftests/cgroup/.gitignore b/tools/testing/selftests/cgroup/.gitignore
> > index aa6de65b0838..84cfcabea838 100644
> > --- a/tools/testing/selftests/cgroup/.gitignore
> > +++ b/tools/testing/selftests/cgroup/.gitignore
> > @@ -2,3 +2,4 @@
> > test_memcontrol
> > test_core
> > test_freezer
> > +test_kmem
> > \ No newline at end of file
> > diff --git a/tools/testing/selftests/cgroup/Makefile b/tools/testing/selftests/cgroup/Makefile
> > index 967f268fde74..4794844a228e 100644
> > --- a/tools/testing/selftests/cgroup/Makefile
> > +++ b/tools/testing/selftests/cgroup/Makefile
> > @@ -6,11 +6,13 @@ all:
> > TEST_FILES := with_stress.sh
> > TEST_PROGS := test_stress.sh
> > TEST_GEN_PROGS = test_memcontrol
> > +TEST_GEN_PROGS = test_kmem
>
> Should be +=
>
> > TEST_GEN_PROGS += test_core
> > TEST_GEN_PROGS += test_freezer
> >
> > include ../lib.mk
> >
> > $(OUTPUT)/test_memcontrol: cgroup_util.c ../clone3/clone3_selftests.h
> > +$(OUTPUT)/test_kmem: cgroup_util.c ../clone3/clone3_selftests.h
> > $(OUTPUT)/test_core: cgroup_util.c ../clone3/clone3_selftests.h
> > $(OUTPUT)/test_freezer: cgroup_util.c ../clone3/clone3_selftests.h
> > diff --git a/tools/testing/selftests/cgroup/test_kmem.c b/tools/testing/selftests/cgroup/test_kmem.c
> > new file mode 100644
> > index 000000000000..5bc1132fec6b
> > --- /dev/null
> > +++ b/tools/testing/selftests/cgroup/test_kmem.c
> > @@ -0,0 +1,382 @@
> ...
> > +/*
> > + * This test allocates 100000 of negative dentries with long names.
> > + * Then it checks that "slab" in memory.stat is larger than 1M.
> > + * Then it sets memory.high to 1M and checks that at least 1/2
> > + * of slab memory has been reclaimed.
> > + */
> > +static int test_kmem_basic(const char *root)
> > +{
> > + int ret = KSFT_FAIL;
> > + char *cg = NULL;
> > + long slab0, slab1, current;
> > +
> > + cg = cg_name(root, "kmem_basic_test");
> > + if (!cg)
> > + goto cleanup;
> > +
> > + if (cg_create(cg))
> > + goto cleanup;
> > +
> > + if (cg_run(cg, alloc_dcache, (void *)100000))
> > + goto cleanup;
> > +
> > + slab0 = cg_read_key_long(cg, "memory.stat", "slab ");
> > + if (slab0 < (1 >> 20))
>
> 1 << 20 ?
>
> Anyway I was getting this:
> not ok 1 test_kmem_basic
> ok 2 test_kmem_memcg_deletion
> ok 3 test_kmem_proc_kpagecgroup
> not ok 4 test_kmem_kernel_stacks
> ok 5 test_kmem_dead_cgroups
>
> Adding some debugging into kmem_basic I found I get memory.stat == 0 at this
> point thus it fails the fixed test (otherwise it was failing the <= 0 test after
> writing to memory.high). But it's just a VM spinned by virtme which has a very
> simple init, so perhaps things are not as initialized as expected.
Hm, it's strange, do you have any values in memory.stat::slab for any cgroups?
Or can you send me your config (and kvm setup), I'll take a look.
Btw, thank you very much for reviewing the series! I appreciate it.
I'll integrate your feedback into the next version, which I'm working on right now.
Thanks!
next prev parent reply other threads:[~2020-05-26 15:45 UTC|newest]
Thread overview: 84+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-22 20:46 [PATCH v3 00/19] The new cgroup slab memory controller Roman Gushchin
2020-04-22 20:46 ` [PATCH v3 01/19] mm: memcg: factor out memcg- and lruvec-level changes out of __mod_lruvec_state() Roman Gushchin
2020-05-07 20:33 ` Johannes Weiner
2020-05-20 10:49 ` Vlastimil Babka
2020-04-22 20:46 ` [PATCH v3 02/19] mm: memcg: prepare for byte-sized vmstat items Roman Gushchin
2020-05-07 20:34 ` Johannes Weiner
2020-05-20 11:31 ` Vlastimil Babka
2020-05-20 11:36 ` Vlastimil Babka
2020-04-22 20:46 ` [PATCH v3 03/19] mm: memcg: convert vmstat slab counters to bytes Roman Gushchin
2020-05-07 20:41 ` Johannes Weiner
2020-05-20 12:25 ` Vlastimil Babka
2020-05-20 19:26 ` Roman Gushchin
2020-05-21 9:57 ` Vlastimil Babka
2020-05-21 21:14 ` Roman Gushchin
2020-04-22 20:46 ` [PATCH v3 04/19] mm: slub: implement SLUB version of obj_to_index() Roman Gushchin
2020-04-22 23:52 ` Christopher Lameter
2020-04-23 0:05 ` Roman Gushchin
2020-04-25 2:10 ` Christopher Lameter
2020-04-25 2:46 ` Roman Gushchin
2020-04-27 16:21 ` Christopher Lameter
2020-04-27 16:46 ` Roman Gushchin
2020-04-28 17:06 ` Roman Gushchin
2020-04-28 17:45 ` Johannes Weiner
2020-04-30 16:29 ` Christopher Lameter
2020-04-30 17:15 ` Roman Gushchin
2020-05-02 23:54 ` Christopher Lameter
2020-05-04 18:29 ` Roman Gushchin
2020-05-08 21:35 ` Christopher Lameter
2020-05-13 0:57 ` Roman Gushchin
2020-05-15 21:45 ` Christopher Lameter
2020-05-15 22:12 ` Roman Gushchin
2020-05-20 9:51 ` Vlastimil Babka
2020-05-20 20:57 ` Roman Gushchin
2020-05-15 20:02 ` Roman Gushchin
2020-04-23 21:01 ` Roman Gushchin
2020-04-25 2:10 ` Christopher Lameter
2020-05-20 13:51 ` Vlastimil Babka
2020-05-20 21:00 ` Roman Gushchin
2020-05-21 11:01 ` Vlastimil Babka
2020-05-21 21:06 ` Roman Gushchin
2020-04-22 20:46 ` [PATCH v3 05/19] mm: memcontrol: decouple reference counting from page accounting Roman Gushchin
2020-04-22 20:46 ` [PATCH v3 06/19] mm: memcg/slab: obj_cgroup API Roman Gushchin
2020-05-07 21:03 ` Johannes Weiner
2020-05-07 22:26 ` Roman Gushchin
2020-05-12 22:56 ` Johannes Weiner
2020-05-15 22:01 ` Roman Gushchin
2020-04-22 20:46 ` [PATCH v3 07/19] mm: memcg/slab: allocate obj_cgroups for non-root slab pages Roman Gushchin
2020-04-23 20:20 ` Roman Gushchin
2020-05-22 18:27 ` Vlastimil Babka
2020-05-23 1:32 ` Roman Gushchin
2020-05-26 17:50 ` Roman Gushchin
2020-05-25 14:46 ` Vlastimil Babka
2020-04-22 20:46 ` [PATCH v3 08/19] mm: memcg/slab: save obj_cgroup for non-root slab objects Roman Gushchin
2020-05-25 15:07 ` Vlastimil Babka
2020-05-26 17:53 ` Roman Gushchin
2020-05-27 11:03 ` Vlastimil Babka
2020-04-22 20:46 ` [PATCH v3 09/19] mm: memcg/slab: charge individual slab objects instead of pages Roman Gushchin
2020-05-25 16:10 ` Vlastimil Babka
2020-05-26 18:04 ` Roman Gushchin
2020-04-22 20:46 ` [PATCH v3 10/19] mm: memcg/slab: deprecate memory.kmem.slabinfo Roman Gushchin
2020-05-07 21:05 ` Johannes Weiner
2020-04-22 20:47 ` [PATCH v3 11/19] mm: memcg/slab: move memcg_kmem_bypass() to memcontrol.h Roman Gushchin
2020-05-25 17:03 ` Vlastimil Babka
2020-04-22 20:47 ` [PATCH v3 12/19] mm: memcg/slab: use a single set of kmem_caches for all accounted allocations Roman Gushchin
2020-05-26 10:12 ` Vlastimil Babka
2020-04-22 20:47 ` [PATCH v3 13/19] mm: memcg/slab: simplify memcg cache creation Roman Gushchin
2020-05-26 10:31 ` Vlastimil Babka
2020-04-22 20:47 ` [PATCH v3 14/19] mm: memcg/slab: deprecate memcg_kmem_get_cache() Roman Gushchin
2020-05-26 10:34 ` Vlastimil Babka
2020-04-22 20:47 ` [PATCH v3 15/19] mm: memcg/slab: deprecate slab_root_caches Roman Gushchin
2020-05-26 10:52 ` Vlastimil Babka
2020-05-26 18:50 ` Roman Gushchin
2020-04-22 20:47 ` [PATCH v3 16/19] mm: memcg/slab: remove redundant check in memcg_accumulate_slabinfo() Roman Gushchin
2020-05-26 11:31 ` Vlastimil Babka
2020-04-22 20:47 ` [PATCH v3 17/19] mm: memcg/slab: use a single set of kmem_caches for all allocations Roman Gushchin
2020-05-26 14:55 ` Vlastimil Babka
2020-05-27 8:35 ` Jesper Dangaard Brouer
2020-04-22 20:47 ` [PATCH v3 18/19] kselftests: cgroup: add kernel memory accounting tests Roman Gushchin
2020-05-26 15:24 ` Vlastimil Babka
2020-05-26 15:45 ` Roman Gushchin [this message]
2020-05-27 17:00 ` Vlastimil Babka
2020-05-27 20:45 ` Roman Gushchin
2020-04-22 20:47 ` [PATCH v3 19/19] tools/cgroup: add memcg_slabinfo.py tool Roman Gushchin
2020-05-05 15:59 ` Tejun Heo
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