user/sven/linux.git/include/linux/slab_def.h, branch v4.4.159

slab: embed memcg_cache_params to kmem_cache

2015-02-13T02:54:09Z

Currently, kmem_cache stores a pointer to struct memcg_cache_params instead of embedding it. The rationale is to save memory when kmem accounting is disabled. However, the memcg_cache_params has shrivelled drastically since it was first introduced: * Initially: struct memcg_cache_params { bool is_root_cache; union { struct kmem_cache *memcg_caches[0]; struct { struct mem_cgroup *memcg; struct list_head list; struct kmem_cache *root_cache; bool dead; atomic_t nr_pages; struct work_struct destroy; }; }; }; * Now: struct memcg_cache_params { bool is_root_cache; union { struct { struct rcu_head rcu_head; struct kmem_cache *memcg_caches[0]; }; struct { struct mem_cgroup *memcg; struct kmem_cache *root_cache; }; }; }; So the memory saving does not seem to be a clear win anymore. OTOH, keeping a pointer to memcg_cache_params struct instead of embedding it results in touching one more cache line on kmem alloc/free hot paths. Besides, it makes linking kmem caches in a list chained by a field of struct memcg_cache_params really painful due to a level of indirection, while I want to make them linked in the following patch. That said, let us embed it. Signed-off-by: Vladimir Davydov Cc: Johannes Weiner Cc: Michal Hocko Cc: Tejun Heo Cc: Christoph Lameter Cc: Pekka Enberg Cc: David Rientjes Cc: Joonsoo Kim Cc: Dave Chinner Cc: Dan Carpenter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/slab: use percpu allocator for cpu cache

2014-10-10T02:25:51Z

Because of chicken and egg problem, initialization of SLAB is really complicated. We need to allocate cpu cache through SLAB to make the kmem_cache work, but before initialization of kmem_cache, allocation through SLAB is impossible. On the other hand, SLUB does initialization in a more simple way. It uses percpu allocator to allocate cpu cache so there is no chicken and egg problem. So, this patch try to use percpu allocator in SLAB. This simplifies the initialization step in SLAB so that we could maintain SLAB code more easily. In my testing there is no performance difference. This implementation relies on percpu allocator. Because percpu allocator uses vmalloc address space, vmalloc address space could be exhausted by this change on many cpu system with *32 bit* kernel. This implementation can cover 1024 cpus in worst case by following calculation. Worst: 1024 cpus * 4 bytes for pointer * 300 kmem_caches * 120 objects per cpu_cache = 140 MB Normal: 1024 cpus * 4 bytes for pointer * 150 kmem_caches(slab merge) * 80 objects per cpu_cache = 46 MB Signed-off-by: Joonsoo Kim Acked-by: Christoph Lameter Cc: Pekka Enberg Cc: David Rientjes Cc: Jeremiah Mahler Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next

2014-01-25T19:17:34Z

Pull networking updates from David Miller: 1) BPF debugger and asm tool by Daniel Borkmann. 2) Speed up create/bind in AF_PACKET, also from Daniel Borkmann. 3) Correct reciprocal_divide and update users, from Hannes Frederic Sowa and Daniel Borkmann. 4) Currently we only have a "set" operation for the hw timestamp socket ioctl, add a "get" operation to match. From Ben Hutchings. 5) Add better trace events for debugging driver datapath problems, also from Ben Hutchings. 6) Implement auto corking in TCP, from Eric Dumazet. Basically, if we have a small send and a previous packet is already in the qdisc or device queue, defer until TX completion or we get more data. 7) Allow userspace to manage ipv6 temporary addresses, from Jiri Pirko. 8) Add a qdisc bypass option for AF_PACKET sockets, from Daniel Borkmann. 9) Share IP header compression code between Bluetooth and IEEE802154 layers, from Jukka Rissanen. 10) Fix ipv6 router reachability probing, from Jiri Benc. 11) Allow packets to be captured on macvtap devices, from Vlad Yasevich. 12) Support tunneling in GRO layer, from Jerry Chu. 13) Allow bonding to be configured fully using netlink, from Scott Feldman. 14) Allow AF_PACKET users to obtain the VLAN TPID, just like they can already get the TCI. From Atzm Watanabe. 15) New "Heavy Hitter" qdisc, from Terry Lam. 16) Significantly improve the IPSEC support in pktgen, from Fan Du. 17) Allow ipv4 tunnels to cache routes, just like sockets. From Tom Herbert. 18) Add Proportional Integral Enhanced packet scheduler, from Vijay Subramanian. 19) Allow openvswitch to mmap'd netlink, from Thomas Graf. 20) Key TCP metrics blobs also by source address, not just destination address. From Christoph Paasch. 21) Support 10G in generic phylib. From Andy Fleming. 22) Try to short-circuit GRO flow compares using device provided RX hash, if provided. From Tom Herbert. The wireless and netfilter folks have been busy little bees too. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (2064 commits) net/cxgb4: Fix referencing freed adapter ipv6: reallocate addrconf router for ipv6 address when lo device up fib_frontend: fix possible NULL pointer dereference rtnetlink: remove IFLA_BOND_SLAVE definition rtnetlink: remove check for fill_slave_info in rtnl_have_link_slave_info qlcnic: update version to 5.3.55 qlcnic: Enhance logic to calculate msix vectors. qlcnic: Refactor interrupt coalescing code for all adapters. qlcnic: Update poll controller code path qlcnic: Interrupt code cleanup qlcnic: Enhance Tx timeout debugging. qlcnic: Use bool for rx_mac_learn. bonding: fix u64 division rtnetlink: add missing IFLA_BOND_AD_INFO_UNSPEC sfc: Use the correct maximum TX DMA ring size for SFC9100 Add Shradha Shah as the sfc driver maintainer. net/vxlan: Share RX skb de-marking and checksum checks with ovs tulip: cleanup by using ARRAY_SIZE() ip_tunnel: clear IPCB in ip_tunnel_xmit() in case dst_link_failure() is called net/cxgb4: Don't retrieve stats during recovery ...

reciprocal_divide: update/correction of the algorithm

2014-01-22T07:17:20Z

Jakub Zawadzki noticed that some divisions by reciprocal_divide() were not correct [1][2], which he could also show with BPF code after divisions are transformed into reciprocal_value() for runtime invariance which can be passed to reciprocal_divide() later on; reverse in BPF dump ended up with a different, off-by-one K in some situations. This has been fixed by Eric Dumazet in commit aee636c4809fa5 ("bpf: do not use reciprocal divide"). This follow-up patch improves reciprocal_value() and reciprocal_divide() to work in all cases by using Granlund and Montgomery method, so that also future use is safe and without any non-obvious side-effects. Known problems with the old implementation were that division by 1 always returned 0 and some off-by-ones when the dividend and divisor where very large. This seemed to not be problematic with its current users, as far as we can tell. Eric Dumazet checked for the slab usage, we cannot surely say so in the case of flex_array. Still, in order to fix that, we propose an extension from the original implementation from commit 6a2d7a955d8d resp. [3][4], by using the algorithm proposed in "Division by Invariant Integers Using Multiplication" [5], Torbjörn Granlund and Peter L. Montgomery, that is, pseudocode for q = n/d where q, n, d is in u32 universe: 1) Initialization: int l = ceil(log_2 d) uword m' = floor((1<<32)*((1<>32 q = (t+((n-t)>>sh_1))>>sh_2 The assembler implementation from Agner Fog [6] also helped a lot while implementing. We have tested the implementation on x86_64, ppc64, i686, s390x; on x86_64/haswell we're still half the latency compared to normal divide. Joint work with Daniel Borkmann. [1] http://www.wireshark.org/~darkjames/reciprocal-buggy.c [2] http://www.wireshark.org/~darkjames/set-and-dump-filter-k-bug.c [3] https://gmplib.org/~tege/division-paper.pdf [4] http://homepage.cs.uiowa.edu/~jones/bcd/divide.html [5] http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1.2556 [6] http://www.agner.org/optimize/asmlib.zip Reported-by: Jakub Zawadzki Cc: Eric Dumazet Cc: Austin S Hemmelgarn Cc: linux-kernel@vger.kernel.org Cc: Jesse Gross Cc: Jamal Hadi Salim Cc: Stephen Hemminger Cc: Matt Mackall Cc: Pekka Enberg Cc: Christoph Lameter Cc: Andy Gospodarek Cc: Veaceslav Falico Cc: Jay Vosburgh Cc: Jakub Zawadzki Signed-off-by: Daniel Borkmann Signed-off-by: Hannes Frederic Sowa Signed-off-by: David S. Miller

slab: struct kmem_cache is protected by slab_mutex

2014-01-21T06:53:18Z

cache_chain_mutex has been replaced by slab_mutex. Fix this remaining outdated comment. Signed-off-by: Fam Zheng Signed-off-by: Jiri Kosina

Merge branch 'slab/next' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux

2013-11-22T16:10:34Z

Pull SLAB changes from Pekka Enberg: "The patches from Joonsoo Kim switch mm/slab.c to use 'struct page' for slab internals similar to mm/slub.c. This reduces memory usage and improves performance: https://lkml.org/lkml/2013/10/16/155 Rest of the changes are bug fixes from various people" * 'slab/next' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux: (21 commits) mm, slub: fix the typo in mm/slub.c mm, slub: fix the typo in include/linux/slub_def.h slub: Handle NULL parameter in kmem_cache_flags slab: replace non-existing 'struct freelist *' with 'void *' slab: fix to calm down kmemleak warning slub: proper kmemleak tracking if CONFIG_SLUB_DEBUG disabled slab: rename slab_bufctl to slab_freelist slab: remove useless statement for checking pfmemalloc slab: use struct page for slab management slab: replace free and inuse in struct slab with newly introduced active slab: remove SLAB_LIMIT slab: remove kmem_bufctl_t slab: change the management method of free objects of the slab slab: use __GFP_COMP flag for allocating slab pages slab: use well-defined macro, virt_to_slab() slab: overloading the RCU head over the LRU for RCU free slab: remove cachep in struct slab_rcu slab: remove nodeid in struct slab slab: remove colouroff in struct slab slab: change return type of kmem_getpages() to struct page ...

slab: use struct page for slab management

2013-10-24T17:17:34Z

Now, there are a few field in struct slab, so we can overload these over struct page. This will save some memory and reduce cache footprint. After this change, slabp_cache and slab_size no longer related to a struct slab, so rename them as freelist_cache and freelist_size. These changes are just mechanical ones and there is no functional change. Acked-by: Andi Kleen Acked-by: Christoph Lameter Signed-off-by: Joonsoo Kim Signed-off-by: Pekka Enberg

mm/sl[aou]b: Move kmallocXXX functions to common code

2013-09-04T17:51:33Z

The kmalloc* functions of all slab allcoators are similar now so lets move them into slab.h. This requires some function naming changes in slob. As a results of this patch there is a common set of functions for all allocators. Also means that kmalloc_large() is now available in general to perform large order allocations that go directly via the page allocator. kmalloc_large() can be substituted if kmalloc() throws warnings because of too large allocations. kmalloc_large() has exactly the same semantics as kmalloc but can only used for allocations > PAGE_SIZE. Signed-off-by: Christoph Lameter Signed-off-by: Pekka Enberg

slab: Return NULL for oversized allocations

2013-05-06T06:24:16Z

The inline path seems to have changed the SLAB behavior for very large kmalloc allocations with commit e3366016 ("slab: Use common kmalloc_index/kmalloc_size functions"). This patch restores the old behavior but also adds diagnostics so that we can figure where in the code these large allocations occur. Reported-and-tested-by: Tetsuo Handa Signed-off-by: Christoph Lameter Link: http://lkml.kernel.org/r/201305040348.CIF81716.OStQOHFJMFLOVF@I-love.SAKURA.ne.jp [ penberg@kernel.org: use WARN_ON_ONCE ] Signed-off-by: Pekka Enberg

slab: Common definition for the array of kmalloc caches

2013-02-01T10:32:07Z

Have a common definition fo the kmalloc cache arrays in SLAB and SLUB Acked-by: Glauber Costa Signed-off-by: Christoph Lameter Signed-off-by: Pekka Enberg