linux-toradex.git/mm/slab.h, branch v3.10.46

memcg: check that kmem_cache has memcg_params before accessing it

2013-09-08T05:09:58+00:00

commit 6f6b8951897e487ea6f77b90ea01f70a9c363770 upstream.

If the system had a few memory groups and all of them were destroyed,
memcg_limited_groups_array_size has non-zero value, but all new caches
are created without memcg_params, because memcg_kmem_enabled() returns
false.

We try to enumirate child caches in a few places and all of them are
potentially dangerous.

For example my kernel is compiled with CONFIG_SLAB and it crashed when I
tryed to mount a NFS share after a few experiments with kmemcg.

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
  IP: [] do_tune_cpucache+0x8a/0xd0
  PGD b942a067 PUD b999f067 PMD 0
  Oops: 0000 [#1] SMP
  Modules linked in: fscache(+) ip6table_filter ip6_tables iptable_filter ip_tables i2c_piix4 pcspkr virtio_net virtio_balloon i2c_core floppy
  CPU: 0 PID: 357 Comm: modprobe Not tainted 3.11.0-rc7+ #59
  Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
  task: ffff8800b9f98240 ti: ffff8800ba32e000 task.ti: ffff8800ba32e000
  RIP: 0010:[]  [] do_tune_cpucache+0x8a/0xd0
  RSP: 0018:ffff8800ba32fb70  EFLAGS: 00010246
  RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000006
  RDX: 0000000000000000 RSI: ffff8800b9f98910 RDI: 0000000000000246
  RBP: ffff8800ba32fba0 R08: 0000000000000002 R09: 0000000000000004
  R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000010
  R13: 0000000000000008 R14: 00000000000000d0 R15: ffff8800375d0200
  FS:  00007f55f1378740(0000) GS:ffff8800bfa00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
  CR2: 00007f24feba57a0 CR3: 0000000037b51000 CR4: 00000000000006f0
  Call Trace:
    enable_cpucache+0x49/0x100
    setup_cpu_cache+0x215/0x280
    __kmem_cache_create+0x2fa/0x450
    kmem_cache_create_memcg+0x214/0x350
    kmem_cache_create+0x2b/0x30
    fscache_init+0x19b/0x230 [fscache]
    do_one_initcall+0xfa/0x1b0
    load_module+0x1c41/0x26d0
    SyS_finit_module+0x86/0xb0
    system_call_fastpath+0x16/0x1b

Signed-off-by: Andrey Vagin 
Cc: Pekka Enberg 
Cc: Christoph Lameter 
Cc: Glauber Costa 
Cc: Joonsoo Kim 
Cc: Michal Hocko 
Cc: Johannes Weiner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

slab: Common definition for kmem_cache_node

2013-02-01T10:32:09+00:00

Put the definitions for the kmem_cache_node structures together so that
we have one structure. That will allow us to create more common fields in
the future which could yield more opportunities to share code.

Signed-off-by: Christoph Lameter 
Signed-off-by: Pekka Enberg

slab: Rename list3/l3 to node

2013-02-01T10:32:09+00:00

The list3 or l3 pointers are pointing to per node structures. Reflect
that in the names of variables used.

Signed-off-by: Christoph Lameter 
Signed-off-by: Pekka Enberg

slab: Common Kmalloc cache determination

2013-02-01T10:32:08+00:00

Extract the optimized lookup functions from slub and put them into
slab_common.c. Then make slab use these functions as well.

Joonsoo notes that this fixes some issues with constant folding which
also reduces the code size for slub.

https://lkml.org/lkml/2012/10/20/82

Signed-off-by: Christoph Lameter 
Signed-off-by: Pekka Enberg

slab: Common function to create the kmalloc array

2013-02-01T10:32:08+00:00

The kmalloc array is created in similar ways in both SLAB
and SLUB. Create a common function and have both allocators
call that function.

V1->V2:
	Whitespace cleanup

Reviewed-by: Glauber Costa 
Signed-off-by: Christoph Lameter 
Signed-off-by: Pekka Enberg

slab: propagate tunable values

2012-12-18T23:02:14+00:00

SLAB allows us to tune a particular cache behavior with tunables.  When
creating a new memcg cache copy, we'd like to preserve any tunables the
parent cache already had.

This could be done by an explicit call to do_tune_cpucache() after the
cache is created.  But this is not very convenient now that the caches are
created from common code, since this function is SLAB-specific.

Another method of doing that is taking advantage of the fact that
do_tune_cpucache() is always called from enable_cpucache(), which is
called at cache initialization.  We can just preset the values, and then
things work as expected.

It can also happen that a root cache has its tunables updated during
normal system operation.  In this case, we will propagate the change to
all caches that are already active.

This change will require us to move the assignment of root_cache in
memcg_params a bit earlier.  We need this to be already set - which
memcg_kmem_register_cache will do - when we reach __kmem_cache_create()

Signed-off-by: Glauber Costa 
Cc: Christoph Lameter 
Cc: David Rientjes 
Cc: Frederic Weisbecker 
Cc: Greg Thelen 
Cc: Johannes Weiner 
Cc: JoonSoo Kim 
Cc: KAMEZAWA Hiroyuki 
Cc: Mel Gorman 
Cc: Michal Hocko 
Cc: Pekka Enberg 
Cc: Rik van Riel 
Cc: Suleiman Souhlal 
Cc: Tejun Heo 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

memcg: aggregate memcg cache values in slabinfo

2012-12-18T23:02:14+00:00

When we create caches in memcgs, we need to display their usage
information somewhere.  We'll adopt a scheme similar to /proc/meminfo,
with aggregate totals shown in the global file, and per-group information
stored in the group itself.

For the time being, only reads are allowed in the per-group cache.

Signed-off-by: Glauber Costa 
Cc: Christoph Lameter 
Cc: David Rientjes 
Cc: Frederic Weisbecker 
Cc: Greg Thelen 
Cc: Johannes Weiner 
Cc: JoonSoo Kim 
Cc: KAMEZAWA Hiroyuki 
Cc: Mel Gorman 
Cc: Michal Hocko 
Cc: Pekka Enberg 
Cc: Rik van Riel 
Cc: Suleiman Souhlal 
Cc: Tejun Heo 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

memcg: destroy memcg caches

2012-12-18T23:02:14+00:00

Implement destruction of memcg caches.  Right now, only caches where our
reference counter is the last remaining are deleted.  If there are any
other reference counters around, we just leave the caches lying around
until they go away.

When that happens, a destruction function is called from the cache code.
Caches are only destroyed in process context, so we queue them up for
later processing in the general case.

Signed-off-by: Glauber Costa 
Cc: Christoph Lameter 
Cc: David Rientjes 
Cc: Frederic Weisbecker 
Cc: Greg Thelen 
Cc: Johannes Weiner 
Cc: JoonSoo Kim 
Cc: KAMEZAWA Hiroyuki 
Cc: Mel Gorman 
Cc: Michal Hocko 
Cc: Pekka Enberg 
Cc: Rik van Riel 
Cc: Suleiman Souhlal 
Cc: Tejun Heo 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

sl[au]b: always get the cache from its page in kmem_cache_free()

2012-12-18T23:02:14+00:00

struct page already has this information.  If we start chaining caches,
this information will always be more trustworthy than whatever is passed
into the function.

Signed-off-by: Glauber Costa 
Cc: Christoph Lameter 
Cc: David Rientjes 
Cc: Frederic Weisbecker 
Cc: Greg Thelen 
Cc: Johannes Weiner 
Cc: JoonSoo Kim 
Cc: KAMEZAWA Hiroyuki 
Cc: Mel Gorman 
Cc: Michal Hocko 
Cc: Pekka Enberg 
Cc: Rik van Riel 
Cc: Suleiman Souhlal 
Cc: Tejun Heo 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

slab/slub: consider a memcg parameter in kmem_create_cache

2012-12-18T23:02:13+00:00

Allow a memcg parameter to be passed during cache creation.  When the slub
allocator is being used, it will only merge caches that belong to the same
memcg.  We'll do this by scanning the global list, and then translating
the cache to a memcg-specific cache

Default function is created as a wrapper, passing NULL to the memcg
version.  We only merge caches that belong to the same memcg.

A helper is provided, memcg_css_id: because slub needs a unique cache name
for sysfs.  Since this is visible, but not the canonical location for slab
data, the cache name is not used, the css_id should suffice.

Signed-off-by: Glauber Costa 
Cc: Christoph Lameter 
Cc: David Rientjes 
Cc: Frederic Weisbecker 
Cc: Greg Thelen 
Cc: Johannes Weiner 
Cc: JoonSoo Kim 
Cc: KAMEZAWA Hiroyuki 
Cc: Mel Gorman 
Cc: Michal Hocko 
Cc: Pekka Enberg 
Cc: Rik van Riel 
Cc: Suleiman Souhlal 
Cc: Tejun Heo 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds