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* Merge branch 'perf/core' of ↵Ingo Molnar2010-06-09
|\ | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing into perf/core
| * tracing: Remove kmemtrace ftrace pluginLi Zefan2010-06-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | We have been resisting new ftrace plugins and removing existing ones, and kmemtrace has been superseded by kmem trace events and perf-kmem, so we remove it. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> Cc: Ingo Molnar <mingo@elte.hu> Cc: Steven Rostedt <rostedt@goodmis.org> [ remove kmemtrace from the makefile, handle slob too ] Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
* | SLUB: Allow full duplication of kmalloc array for 390Christoph Lameter2010-05-30
| | | | | | | | | | | | | | | | | | | | | | | | Commit 756dee75872a2a764b478e18076360b8a4ec9045 ("SLUB: Get rid of dynamic DMA kmalloc cache allocation") makes S390 run out of kmalloc caches. Increase the number of kmalloc caches to a safe size. Cc: <stable@kernel.org> [ .33 and .34 ] Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com> Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
* | slub: move kmem_cache_node into it's own cachelineAlexander Duyck2010-05-24
|/ | | | | | | | | | | | | | | | | | | | This patch is meant to improve the performance of SLUB by moving the local kmem_cache_node lock into it's own cacheline separate from kmem_cache. This is accomplished by simply removing the local_node when NUMA is enabled. On my system with 2 nodes I saw around a 5% performance increase w/ hackbench times dropping from 6.2 seconds to 5.9 seconds on average. I suspect the performance gain would increase as the number of nodes increases, but I do not have the data to currently back that up. Bugzilla-Reference: http://bugzilla.kernel.org/show_bug.cgi?id=15713 Cc: <stable@kernel.org> Reported-by: Alex Shi <alex.shi@intel.com> Tested-by: Alex Shi <alex.shi@intel.com> Acked-by: Yanmin Zhang <yanmin_zhang@linux.intel.com> Acked-by: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
* mm: Move ARCH_SLAB_MINALIGN and ARCH_KMALLOC_MINALIGN to <linux/slub_def.h>David Woodhouse2010-05-19
| | | | | | Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
* SLUB: this_cpu: Remove slub kmem_cache fieldsChristoph Lameter2009-12-20
| | | | | | | | | | | | | | | | | | | Remove the fields in struct kmem_cache_cpu that were used to cache data from struct kmem_cache when they were in different cachelines. The cacheline that holds the per cpu array pointer now also holds these values. We can cut down the struct kmem_cache_cpu size to almost half. The get_freepointer() and set_freepointer() functions that used to be only intended for the slow path now are also useful for the hot path since access to the size field does not require accessing an additional cacheline anymore. This results in consistent use of functions for setting the freepointer of objects throughout SLUB. Also we initialize all possible kmem_cache_cpu structures when a slab is created. No need to initialize them when a processor or node comes online. Signed-off-by: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
* SLUB: Get rid of dynamic DMA kmalloc cache allocationChristoph Lameter2009-12-20
| | | | | | | | | Dynamic DMA kmalloc cache allocation is troublesome since the new percpu allocator does not support allocations in atomic contexts. Reserve some statically allocated kmalloc_cpu structures instead. Signed-off-by: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
* SLUB: Use this_cpu operations in slubChristoph Lameter2009-12-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Using per cpu allocations removes the needs for the per cpu arrays in the kmem_cache struct. These could get quite big if we have to support systems with thousands of cpus. The use of this_cpu_xx operations results in: 1. The size of kmem_cache for SMP configuration shrinks since we will only need 1 pointer instead of NR_CPUS. The same pointer can be used by all processors. Reduces cache footprint of the allocator. 2. We can dynamically size kmem_cache according to the actual nodes in the system meaning less memory overhead for configurations that may potentially support up to 1k NUMA nodes / 4k cpus. 3. We can remove the diddle widdle with allocating and releasing of kmem_cache_cpu structures when bringing up and shutting down cpus. The cpu alloc logic will do it all for us. Removes some portions of the cpu hotplug functionality. 4. Fastpath performance increases since per cpu pointer lookups and address calculations are avoided. V7-V8 - Convert missed get_cpu_slab() under CONFIG_SLUB_STATS Signed-off-by: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
* tracing, slab: Define kmem_cache_alloc_notrace ifdef CONFIG_TRACINGLi Zefan2009-12-11
| | | | | | | | | | | | | | | | | Define kmem_trace_alloc_{,node}_notrace() if CONFIG_TRACING is enabled, otherwise perf-kmem will show wrong stats ifndef CONFIG_KMEM_TRACE, because a kmalloc() memory allocation may be traced by both trace_kmalloc() and trace_kmem_cache_alloc(). Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: linux-mm@kvack.org <linux-mm@kvack.org> Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> LKML-Reference: <4B21F89A.7000801@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
*-. Merge branches 'slab/cleanups' and 'slab/fixes' into for-linusPekka Enberg2009-09-14
|\ \
| | * SLUB: fix ARCH_KMALLOC_MINALIGN cases 64 and 256Aaro Koskinen2009-08-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the minalign is 64 bytes, then the 96 byte cache should not be created because it would conflict with the 128 byte cache. If the minalign is 256 bytes, patching the size_index table should not result in a buffer overrun. The calculation "(i - 1) / 8" used to access size_index[] is moved to a separate function as suggested by Christoph Lameter. Acked-by: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Aaro Koskinen <aaro.koskinen@nokia.com> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
| * | slab: remove duplicate kmem_cache_init_late() declarationsWu Fengguang2009-08-06
|/ / | | | | | | | | | | | | | | | | | | kmem_cache_init_late() has been declared in slab.h CC: Nick Piggin <npiggin@suse.de> CC: Matt Mackall <mpm@selenic.com> CC: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
* / kmemleak: Trace the kmalloc_large* functions in slubCatalin Marinas2009-07-08
|/ | | | | | | | | | The kmalloc_large() and kmalloc_large_node() functions were missed when adding the kmemleak hooks to the slub allocator. However, they should be traced to avoid false positives. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Christoph Lameter <cl@linux-foundation.org> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
* slab,slub: don't enable interrupts during early bootPekka Enberg2009-06-12
| | | | | | | | | | | | | | | | | | | As explained by Benjamin Herrenschmidt: Oh and btw, your patch alone doesn't fix powerpc, because it's missing a whole bunch of GFP_KERNEL's in the arch code... You would have to grep the entire kernel for things that check slab_is_available() and even then you'll be missing some. For example, slab_is_available() didn't always exist, and so in the early days on powerpc, we used a mem_init_done global that is set form mem_init() (not perfect but works in practice). And we still have code using that to do the test. Therefore, mask out __GFP_WAIT, __GFP_IO, and __GFP_FS in the slab allocators in early boot code to avoid enabling interrupts. Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
* tracing, kmemtrace: Separate include/trace/kmemtrace.h to kmemtrace part and ↵Zhaolei2009-04-12
| | | | | | | | | | | | | | | | | | | | | | | | | | tracepoint part Impact: refactor code for future changes Current kmemtrace.h is used both as header file of kmemtrace and kmem's tracepoints definition. Tracepoints' definition file may be used by other code, and should only have definition of tracepoint. We can separate include/trace/kmemtrace.h into 2 files: include/linux/kmemtrace.h: header file for kmemtrace include/trace/kmem.h: definition of kmem tracepoints Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Acked-by: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Tom Zanussi <tzanussi@gmail.com> LKML-Reference: <49DEE68A.5040902@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* kmemtrace: use tracepointsEduard - Gabriel Munteanu2009-04-03
| | | | | | | | | | | | | kmemtrace now uses tracepoints instead of markers. We no longer need to use format specifiers to pass arguments. Signed-off-by: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> [ folded: Use the new TP_PROTO and TP_ARGS to fix the build. ] [ folded: fix build when CONFIG_KMEMTRACE is disabled. ] [ folded: define tracepoints when CONFIG_TRACEPOINTS is enabled. ] Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> LKML-Reference: <ae61c0f37156db8ec8dc0d5778018edde60a92e3.1237813499.git.eduard.munteanu@linux360.ro> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Merge branch 'tracing/core-v2' into tracing-for-linusIngo Molnar2009-04-01
|\ | | | | | | | | | | | | | | Conflicts: include/linux/slub_def.h lib/Kconfig.debug mm/slob.c mm/slub.c
| * Merge branch 'for-ingo' of ↵Ingo Molnar2009-02-20
| |\ | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6 into tracing/kmemtrace Conflicts: mm/slub.c
| | * SLUB: Introduce and use SLUB_MAX_SIZE and SLUB_PAGE_SHIFT constantsChristoph Lameter2009-02-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As a preparational patch to bump up page allocator pass-through threshold, introduce two new constants SLUB_MAX_SIZE and SLUB_PAGE_SHIFT and convert mm/slub.c to use them. Reported-by: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com> Tested-by: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com> Signed-off-by: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
| * | tracing/kmemtrace: normalize the raw tracer event to the unified tracing APIFrederic Weisbecker2008-12-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: new tracer plugin This patch adapts kmemtrace raw events tracing to the unified tracing API. To enable and use this tracer, just do the following: echo kmemtrace > /debugfs/tracing/current_tracer cat /debugfs/tracing/trace You will have the following output: # tracer: kmemtrace # # # ALLOC TYPE REQ GIVEN FLAGS POINTER NODE CALLER # FREE | | | | | | | | # | type_id 1 call_site 18446744071565527833 ptr 18446612134395152256 type_id 0 call_site 18446744071565585597 ptr 18446612134405955584 bytes_req 4096 bytes_alloc 4096 gfp_flags 208 node -1 type_id 1 call_site 18446744071565585534 ptr 18446612134405955584 type_id 0 call_site 18446744071565585597 ptr 18446612134405955584 bytes_req 4096 bytes_alloc 4096 gfp_flags 208 node -1 type_id 0 call_site 18446744071565636711 ptr 18446612134345164672 bytes_req 240 bytes_alloc 240 gfp_flags 208 node -1 type_id 1 call_site 18446744071565585534 ptr 18446612134405955584 type_id 0 call_site 18446744071565585597 ptr 18446612134405955584 bytes_req 4096 bytes_alloc 4096 gfp_flags 208 node -1 type_id 0 call_site 18446744071565636711 ptr 18446612134345164912 bytes_req 240 bytes_alloc 240 gfp_flags 208 node -1 type_id 1 call_site 18446744071565585534 ptr 18446612134405955584 type_id 0 call_site 18446744071565585597 ptr 18446612134405955584 bytes_req 4096 bytes_alloc 4096 gfp_flags 208 node -1 type_id 0 call_site 18446744071565636711 ptr 18446612134345165152 bytes_req 240 bytes_alloc 240 gfp_flags 208 node -1 type_id 0 call_site 18446744071566144042 ptr 18446612134346191680 bytes_req 1304 bytes_alloc 1312 gfp_flags 208 node -1 type_id 1 call_site 18446744071565585534 ptr 18446612134405955584 type_id 0 call_site 18446744071565585597 ptr 18446612134405955584 bytes_req 4096 bytes_alloc 4096 gfp_flags 208 node -1 type_id 1 call_site 18446744071565585534 ptr 18446612134405955584 That was to stay backward compatible with the format output produced in inux/tracepoint.h. This is the default ouput, but note that I tried something else. If you change an option: echo kmem_minimalistic > /debugfs/trace_options and then cat /debugfs/trace, you will have the following output: # tracer: kmemtrace # # # ALLOC TYPE REQ GIVEN FLAGS POINTER NODE CALLER # FREE | | | | | | | | # | - C 0xffff88007c088780 file_free_rcu + K 4096 4096 000000d0 0xffff88007cad6000 -1 getname - C 0xffff88007cad6000 putname + K 4096 4096 000000d0 0xffff88007cad6000 -1 getname + K 240 240 000000d0 0xffff8800790dc780 -1 d_alloc - C 0xffff88007cad6000 putname + K 4096 4096 000000d0 0xffff88007cad6000 -1 getname + K 240 240 000000d0 0xffff8800790dc870 -1 d_alloc - C 0xffff88007cad6000 putname + K 4096 4096 000000d0 0xffff88007cad6000 -1 getname + K 240 240 000000d0 0xffff8800790dc960 -1 d_alloc + K 1304 1312 000000d0 0xffff8800791d7340 -1 reiserfs_alloc_inode - C 0xffff88007cad6000 putname + K 4096 4096 000000d0 0xffff88007cad6000 -1 getname - C 0xffff88007cad6000 putname + K 992 1000 000000d0 0xffff880079045b58 -1 alloc_inode + K 768 1024 000080d0 0xffff88007c096400 -1 alloc_pipe_info + K 240 240 000000d0 0xffff8800790dca50 -1 d_alloc + K 272 320 000080d0 0xffff88007c088780 -1 get_empty_filp + K 272 320 000080d0 0xffff88007c088000 -1 get_empty_filp Yeah I shall confess kmem_minimalistic should be: kmem_alternative. Whatever, I find it more readable but this a personal opinion of course. We can drop it if you want. On the ALLOC/FREE column, + means an allocation and - a free. On the type column, you have K = kmalloc, C = cache, P = page I would like the flags to be GFP_* strings but that would not be easy to not break the column with strings.... About the node...it seems to always be -1. I don't know why but that shouldn't be difficult to find. I moved linux/tracepoint.h to trace/tracepoint.h as well. I think that would be more easy to find the tracer headers if they are all in their common directory. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | kmemtrace: SLUB hooks.Eduard - Gabriel Munteanu2008-12-29
| |/ | | | | | | | | | | | | This adds hooks for the SLUB allocator, to allow tracing with kmemtrace. Signed-off-by: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
| |
| \
*-. \ Merge branches 'topic/slob/cleanups', 'topic/slob/fixes', 'topic/slub/core', ↵Pekka Enberg2009-03-24
|\ \ \ | |_|/ |/| | | | | 'topic/slub/cleanups' and 'topic/slub/perf' into for-linus
| | * SLUB: Do not pass 8k objects through to the page allocatorPekka Enberg2009-02-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Increase the maximum object size in SLUB so that 8k objects are not passed through to the page allocator anymore. The network stack uses 8k objects for performance critical operations. The patch is motivated by a SLAB vs. SLUB regression in the netperf benchmark. The problem is that the kfree(skb->head) call in skb_release_data() that is subject to page allocator pass-through as the size passed to __alloc_skb() is larger than 4 KB in this test. As explained by Yanmin Zhang: I use 2.6.29-rc2 kernel to run netperf UDP-U-4k CPU_NUM client/server pair loopback testing on x86-64 machines. Comparing with SLUB, SLAB's result is about 2.3 times of SLUB's. After applying the reverting patch, the result difference between SLUB and SLAB becomes 1% which we might consider as fluctuation. [ penberg@cs.helsinki.fi: fix oops in kmalloc() ] Reported-by: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com> Tested-by: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com> Signed-off-by: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
| | * SLUB: Introduce and use SLUB_MAX_SIZE and SLUB_PAGE_SHIFT constantsChristoph Lameter2009-02-20
| |/ |/| | | | | | | | | | | | | | | | | | | As a preparational patch to bump up page allocator pass-through threshold, introduce two new constants SLUB_MAX_SIZE and SLUB_PAGE_SHIFT and convert mm/slub.c to use them. Reported-by: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com> Tested-by: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com> Signed-off-by: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
| * slub: move min_partial to struct kmem_cacheDavid Rientjes2009-02-23
|/ | | | | | | | | Although it allows for better cacheline use, it is unnecessary to save a copy of the cache's min_partial value in each kmem_cache_node. Cc: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
* SLUB: dynamic per-cache MIN_PARTIALPekka Enberg2008-08-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch changes the static MIN_PARTIAL to a dynamic per-cache ->min_partial value that is calculated from object size. The bigger the object size, the more pages we keep on the partial list. I tested SLAB, SLUB, and SLUB with this patch on Jens Axboe's 'netio' example script of the fio benchmarking tool. The script stresses the networking subsystem which should also give a fairly good beating of kmalloc() et al. To run the test yourself, first clone the fio repository: git clone git://git.kernel.dk/fio.git and then run the following command n times on your machine: time ./fio examples/netio The results on my 2-way 64-bit x86 machine are as follows: [ the minimum, maximum, and average are captured from 50 individual runs ] real time (seconds) min max avg sd SLAB 22.76 23.38 22.98 0.17 SLUB 22.80 25.78 23.46 0.72 SLUB (dynamic) 22.74 23.54 23.00 0.20 sys time (seconds) min max avg sd SLAB 6.90 8.28 7.70 0.28 SLUB 7.42 16.95 8.89 2.28 SLUB (dynamic) 7.17 8.64 7.73 0.29 user time (seconds) min max avg sd SLAB 36.89 38.11 37.50 0.29 SLUB 30.85 37.99 37.06 1.67 SLUB (dynamic) 36.75 38.07 37.59 0.32 As you can see from the above numbers, this patch brings SLUB to the same level as SLAB for this particular workload fixing a ~2% regression. I'd expect this change to help similar workloads that allocate a lot of objects that are close to the size of a page. Cc: Matthew Wilcox <matthew@wil.cx> Cc: Andrew Morton <akpm@linux-foundation.org> Acked-by: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
* SL*B: drop kmem cache argument from constructorAlexey Dobriyan2008-07-26
| | | | | | | | | | | | | | | | | | | | | | | | Kmem cache passed to constructor is only needed for constructors that are themselves multiplexeres. Nobody uses this "feature", nor does anybody uses passed kmem cache in non-trivial way, so pass only pointer to object. Non-trivial places are: arch/powerpc/mm/init_64.c arch/powerpc/mm/hugetlbpage.c This is flag day, yes. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: Christoph Lameter <cl@linux-foundation.org> Cc: Jon Tollefson <kniht@linux.vnet.ibm.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Matt Mackall <mpm@selenic.com> [akpm@linux-foundation.org: fix arch/powerpc/mm/hugetlbpage.c] [akpm@linux-foundation.org: fix mm/slab.c] [akpm@linux-foundation.org: fix ubifs] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Christoph has movedChristoph Lameter2008-07-04
| | | | | | | | | | | | | | | Remove all clameter@sgi.com addresses from the kernel tree since they will become invalid on June 27th. Change my maintainer email address for the slab allocators to cl@linux-foundation.org (which will be the new email address for the future). Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Christoph Lameter <cl@linux-foundation.org> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* slub: Do not use 192 byte sized cache if minimum alignment is 128 byteChristoph Lameter2008-07-03
| | | | | | | | | | | | | The 192 byte cache is not necessary if we have a basic alignment of 128 byte. If it would be used then the 192 would be aligned to the next 128 byte boundary which would result in another 256 byte cache. Two 256 kmalloc caches cause sysfs to complain about a duplicate entry. MIPS needs 128 byte aligned kmalloc caches and spits out warnings on boot without this patch. Signed-off-by: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
* slub: Fallback to minimal order during slab page allocationChristoph Lameter2008-04-27
| | | | | | | | | | | | | | | | | | If any higher order allocation fails then fall back the smallest order necessary to contain at least one object. This enables fallback for all allocations to order 0 pages. The fallback will waste more memory (objects will not fit neatly) and the fallback slabs will be not as efficient as larger slabs since they contain less objects. Note that SLAB also depends on order 1 allocations for some slabs that waste too much memory if forced into PAGE_SIZE'd page. SLUB now can now deal with failing order 1 allocs which SLAB cannot do. Add a new field min that will contain the objects for the smallest possible order for a slab cache. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
* slub: Update statistics handling for variable order slabsChristoph Lameter2008-04-27
| | | | | | | | | | | | | | | | | | | Change the statistics to consider that slabs of the same slabcache can have different number of objects in them since they may be of different order. Provide a new sysfs field total_objects which shows the total objects that the allocated slabs of a slabcache could hold. Add a max field that holds the largest slab order that was ever used for a slab cache. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
* slub: Add kmem_cache_order_objects structChristoph Lameter2008-04-27
| | | | | | | | | | | | | | | | Pack the order and the number of objects into a single word. This saves some memory in the kmem_cache_structure and more importantly allows us to fetch both values atomically. Later the slab orders become runtime configurable and we need to fetch these two items together in order to properly allocate a slab and initialize its objects. Fix the race by fetching the order and the number of objects in one word. [penberg@cs.helsinki.fi: fix memset() page order in new_slab()] Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
* slub: No need for per node slab counters if !SLUB_DEBUGChristoph Lameter2008-04-14
| | | | | | | | | | | | | | | | | | | The per node counters are used mainly for showing data through the sysfs API. If that API is not compiled in then there is no point in keeping track of this data. Disable counters for the number of slabs and the number of total slabs if !SLUB_DEBUG. Incrementing the per node counters is also accessing a potentially contended cacheline so this could actually be a performance benefit to embedded systems. SLABINFO support is also affected. It now must depends on SLUB_DEBUG (which is on by default). Patch also avoids a check for a NULL kmem_cache_node pointer in new_slab() if the system is not compiled with NUMA support. [penberg@cs.helsinki.fi: fix oops and move ->nr_slabs into CONFIG_SLUB_DEBUG] Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
* slub: Fix up commentsChristoph Lameter2008-03-03
| | | | | | Provide comments and fix up various spelling / style issues. Signed-off-by: Christoph Lameter <clameter@sgi.com>
* slub: Support 4k kmallocs again to compensate for page allocator slownessChristoph Lameter2008-02-14
| | | | | | | | | | | | | | | | | | | | | Currently we hand off PAGE_SIZEd kmallocs to the page allocator in the mistaken belief that the page allocator can handle these allocations effectively. However, measurements indicate a minimum slowdown by the factor of 8 (and that is only SMP, NUMA is much worse) vs the slub fastpath which causes regressions in tbench. Increase the number of kmalloc caches by one so that we again handle 4k kmallocs directly from slub. 4k page buffering for the page allocator will be performed by slub like done by slab. At some point the page allocator fastpath should be fixed. A lot of the kernel would benefit from a faster ability to allocate a single page. If that is done then the 4k allocs may again be forwarded to the page allocator and this patch could be reverted. Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Christoph Lameter <clameter@sgi.com>
* slub: Determine gfpflags once and not every time a slab is allocatedChristoph Lameter2008-02-14
| | | | | | | | | | | | Currently we determine the gfp flags to pass to the page allocator each time a slab is being allocated. Determine the bits to be set at the time the slab is created. Store in a new allocflags field and add the flags in allocate_slab(). Acked-by: Mel Gorman <mel@csn.ul.ie> Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Christoph Lameter <clameter@sgi.com>
* slub: kmalloc page allocator pass-through cleanupPekka Enberg2008-02-14
| | | | | | | | | This adds a proper function for kmalloc page allocator pass-through. While it simplifies any code that does slab tracing code a lot, I think it's a worthwhile cleanup in itself. Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Christoph Lameter <clameter@sgi.com>
* SLUB: Support for performance statisticsChristoph Lameter2008-02-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The statistics provided here allow the monitoring of allocator behavior but at the cost of some (minimal) loss of performance. Counters are placed in SLUB's per cpu data structure. The per cpu structure may be extended by the statistics to grow larger than one cacheline which will increase the cache footprint of SLUB. There is a compile option to enable/disable the inclusion of the runtime statistics and its off by default. The slabinfo tool is enhanced to support these statistics via two options: -D Switches the line of information displayed for a slab from size mode to activity mode. -A Sorts the slabs displayed by activity. This allows the display of the slabs most important to the performance of a certain load. -r Report option will report detailed statistics on Example (tbench load): slabinfo -AD ->Shows the most active slabs Name Objects Alloc Free %Fast skbuff_fclone_cache 33 111953835 111953835 99 99 :0000192 2666 5283688 5281047 99 99 :0001024 849 5247230 5246389 83 83 vm_area_struct 1349 119642 118355 91 22 :0004096 15 66753 66751 98 98 :0000064 2067 25297 23383 98 78 dentry 10259 28635 18464 91 45 :0000080 11004 18950 8089 98 98 :0000096 1703 12358 10784 99 98 :0000128 762 10582 9875 94 18 :0000512 184 9807 9647 95 81 :0002048 479 9669 9195 83 65 anon_vma 777 9461 9002 99 71 kmalloc-8 6492 9981 5624 99 97 :0000768 258 7174 6931 58 15 So the skbuff_fclone_cache is of highest importance for the tbench load. Pretty high load on the 192 sized slab. Look for the aliases slabinfo -a | grep 000192 :0000192 <- xfs_btree_cur filp kmalloc-192 uid_cache tw_sock_TCP request_sock_TCPv6 tw_sock_TCPv6 skbuff_head_cache xfs_ili Likely skbuff_head_cache. Looking into the statistics of the skbuff_fclone_cache is possible through slabinfo skbuff_fclone_cache ->-r option implied if cache name is mentioned .... Usual output ... Slab Perf Counter Alloc Free %Al %Fr -------------------------------------------------- Fastpath 111953360 111946981 99 99 Slowpath 1044 7423 0 0 Page Alloc 272 264 0 0 Add partial 25 325 0 0 Remove partial 86 264 0 0 RemoteObj/SlabFrozen 350 4832 0 0 Total 111954404 111954404 Flushes 49 Refill 0 Deactivate Full=325(92%) Empty=0(0%) ToHead=24(6%) ToTail=1(0%) Looks good because the fastpath is overwhelmingly taken. skbuff_head_cache: Slab Perf Counter Alloc Free %Al %Fr -------------------------------------------------- Fastpath 5297262 5259882 99 99 Slowpath 4477 39586 0 0 Page Alloc 937 824 0 0 Add partial 0 2515 0 0 Remove partial 1691 824 0 0 RemoteObj/SlabFrozen 2621 9684 0 0 Total 5301739 5299468 Deactivate Full=2620(100%) Empty=0(0%) ToHead=0(0%) ToTail=0(0%) Descriptions of the output: Total: The total number of allocation and frees that occurred for a slab Fastpath: The number of allocations/frees that used the fastpath. Slowpath: Other allocations Page Alloc: Number of calls to the page allocator as a result of slowpath processing Add Partial: Number of slabs added to the partial list through free or alloc (occurs during cpuslab flushes) Remove Partial: Number of slabs removed from the partial list as a result of allocations retrieving a partial slab or by a free freeing the last object of a slab. RemoteObj/Froz: How many times were remotely freed object encountered when a slab was about to be deactivated. Frozen: How many times was free able to skip list processing because the slab was in use as the cpuslab of another processor. Flushes: Number of times the cpuslab was flushed on request (kmem_cache_shrink, may result from races in __slab_alloc) Refill: Number of times we were able to refill the cpuslab from remotely freed objects for the same slab. Deactivate: Statistics how slabs were deactivated. Shows how they were put onto the partial list. In general fastpath is very good. Slowpath without partial list processing is also desirable. Any touching of partial list uses node specific locks which may potentially cause list lock contention. Signed-off-by: Christoph Lameter <clameter@sgi.com>
* Explain kmem_cache_cpu fieldsChristoph Lameter2008-02-04
| | | | | | | Add some comments explaining the fields of the kmem_cache_cpu structure. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* SLUB: rename defrag to remote_node_defrag_ratioChristoph Lameter2008-02-04
| | | | | | | | | | | | The NUMA defrag works by allocating objects from partial slabs on remote nodes. Rename it to remote_node_defrag_ratio to be clear about this. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* Unify /proc/slabinfo configurationLinus Torvalds2008-01-02
| | | | | | | | | | | | Both SLUB and SLAB really did almost exactly the same thing for /proc/slabinfo setup, using duplicate code and per-allocator #ifdef's. This just creates a common CONFIG_SLABINFO that is enabled by both SLUB and SLAB, and shares all the setup code. Maybe SLOB will want this some day too. Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* slub: provide /proc/slabinfoPekka J Enberg2008-01-01
| | | | | | | | | | | | | This adds a read-only /proc/slabinfo file on SLUB, that makes slabtop work. [ mingo@elte.hu: build fix. ] Cc: Andi Kleen <andi@firstfloor.org> Cc: Christoph Lameter <clameter@sgi.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Slab API: remove useless ctor parameter and reorder parametersChristoph Lameter2007-10-17
| | | | | | | | | | | | | | | | | | | | | Slab constructors currently have a flags parameter that is never used. And the order of the arguments is opposite to other slab functions. The object pointer is placed before the kmem_cache pointer. Convert ctor(void *object, struct kmem_cache *s, unsigned long flags) to ctor(struct kmem_cache *s, void *object) throughout the kernel [akpm@linux-foundation.org: coupla fixes] Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* SLUB: Optimize cacheline use for zeroingChristoph Lameter2007-10-16
| | | | | | | | | | | | | | | | | | We touch a cacheline in the kmem_cache structure for zeroing to get the size. However, the hot paths in slab_alloc and slab_free do not reference any other fields in kmem_cache, so we may have to just bring in the cacheline for this one access. Add a new field to kmem_cache_cpu that contains the object size. That cacheline must already be used in the hotpaths. So we save one cacheline on every slab_alloc if we zero. We need to update the kmem_cache_cpu object size if an aliasing operation changes the objsize of an non debug slab. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* SLUB: Place kmem_cache_cpu structures in a NUMA aware wayChristoph Lameter2007-10-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The kmem_cache_cpu structures introduced are currently an array placed in the kmem_cache struct. Meaning the kmem_cache_cpu structures are overwhelmingly on the wrong node for systems with a higher amount of nodes. These are performance critical structures since the per node information has to be touched for every alloc and free in a slab. In order to place the kmem_cache_cpu structure optimally we put an array of pointers to kmem_cache_cpu structs in kmem_cache (similar to SLAB). However, the kmem_cache_cpu structures can now be allocated in a more intelligent way. We would like to put per cpu structures for the same cpu but different slab caches in cachelines together to save space and decrease the cache footprint. However, the slab allocators itself control only allocations per node. We set up a simple per cpu array for every processor with 100 per cpu structures which is usually enough to get them all set up right. If we run out then we fall back to kmalloc_node. This also solves the bootstrap problem since we do not have to use slab allocator functions early in boot to get memory for the small per cpu structures. Pro: - NUMA aware placement improves memory performance - All global structures in struct kmem_cache become readonly - Dense packing of per cpu structures reduces cacheline footprint in SMP and NUMA. - Potential avoidance of exclusive cacheline fetches on the free and alloc hotpath since multiple kmem_cache_cpu structures are in one cacheline. This is particularly important for the kmalloc array. Cons: - Additional reference to one read only cacheline (per cpu array of pointers to kmem_cache_cpu) in both slab_alloc() and slab_free(). [akinobu.mita@gmail.com: fix cpu hotplug offline/online path] Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: "Pekka Enberg" <penberg@cs.helsinki.fi> Cc: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* SLUB: Move page->offset to kmem_cache_cpu->offsetChristoph Lameter2007-10-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | We need the offset from the page struct during slab_alloc and slab_free. In both cases we also reference the cacheline of the kmem_cache_cpu structure. We can therefore move the offset field into the kmem_cache_cpu structure freeing up 16 bits in the page struct. Moving the offset allows an allocation from slab_alloc() without touching the page struct in the hot path. The only thing left in slab_free() that touches the page struct cacheline for per cpu freeing is the checking of SlabDebug(page). The next patch deals with that. Use the available 16 bits to broaden page->inuse. More than 64k objects per slab become possible and we can get rid of the checks for that limitation. No need anymore to shrink the order of slabs if we boot with 2M sized slabs (slub_min_order=9). No need anymore to switch off the offset calculation for very large slabs since the field in the kmem_cache_cpu structure is 32 bits and so the offset field can now handle slab sizes of up to 8GB. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* SLUB: Avoid page struct cacheline bouncing due to remote frees to cpu slabChristoph Lameter2007-10-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A remote free may access the same page struct that also contains the lockless freelist for the cpu slab. If objects have a short lifetime and are freed by a different processor then remote frees back to the slab from which we are currently allocating are frequent. The cacheline with the page struct needs to be repeately acquired in exclusive mode by both the allocating thread and the freeing thread. If this is frequent enough then performance will suffer because of cacheline bouncing. This patchset puts the lockless_freelist pointer in its own cacheline. In order to make that happen we introduce a per cpu structure called kmem_cache_cpu. Instead of keeping an array of pointers to page structs we now keep an array to a per cpu structure that--among other things--contains the pointer to the lockless freelist. The freeing thread can then keep possession of exclusive access to the page struct cacheline while the allocating thread keeps its exclusive access to the cacheline containing the per cpu structure. This works as long as the allocating cpu is able to service its request from the lockless freelist. If the lockless freelist runs empty then the allocating thread needs to acquire exclusive access to the cacheline with the page struct lock the slab. The allocating thread will then check if new objects were freed to the per cpu slab. If so it will keep the slab as the cpu slab and continue with the recently remote freed objects. So the allocating thread can take a series of just freed remote pages and dish them out again. Ideally allocations could be just recycling objects in the same slab this way which will lead to an ideal allocation / remote free pattern. The number of objects that can be handled in this way is limited by the capacity of one slab. Increasing slab size via slub_min_objects/ slub_max_order may increase the number of objects and therefore performance. If the allocating thread runs out of objects and finds that no objects were put back by the remote processor then it will retrieve a new slab (from the partial lists or from the page allocator) and start with a whole new set of objects while the remote thread may still be freeing objects to the old cpu slab. This may then repeat until the new slab is also exhausted. If remote freeing has freed objects in the earlier slab then that earlier slab will now be on the partial freelist and the allocating thread will pick that slab next for allocation. So the loop is extended. However, both threads need to take the list_lock to make the swizzling via the partial list happen. It is likely that this kind of scheme will keep the objects being passed around to a small set that can be kept in the cpu caches leading to increased performance. More code cleanups become possible: - Instead of passing a cpu we can now pass a kmem_cache_cpu structure around. Allows reducing the number of parameters to various functions. - Can define a new node_match() function for NUMA to encapsulate locality checks. Effect on allocations: Cachelines touched before this patch: Write: page cache struct and first cacheline of object Cachelines touched after this patch: Write: kmem_cache_cpu cacheline and first cacheline of object Read: page cache struct (but see later patch that avoids touching that cacheline) The handling when the lockless alloc list runs empty gets to be a bit more complicated since another cacheline has now to be written to. But that is halfway out of the hot path. Effect on freeing: Cachelines touched before this patch: Write: page_struct and first cacheline of object Cachelines touched after this patch depending on how we free: Write(to cpu_slab): kmem_cache_cpu struct and first cacheline of object Write(to other): page struct and first cacheline of object Read(to cpu_slab): page struct to id slab etc. (but see later patch that avoids touching the page struct on free) Read(to other): cpu local kmem_cache_cpu struct to verify its not the cpu slab. Summary: Pro: - Distinct cachelines so that concurrent remote frees and local allocs on a cpuslab can occur without cacheline bouncing. - Avoids potential bouncing cachelines because of neighboring per cpu pointer updates in kmem_cache's cpu_slab structure since it now grows to a cacheline (Therefore remove the comment that talks about that concern). Cons: - Freeing objects now requires the reading of one additional cacheline. That can be mitigated for some cases by the following patches but its not possible to completely eliminate these references. - Memory usage grows slightly. The size of each per cpu object is blown up from one word (pointing to the page_struct) to one cacheline with various data. So this is NR_CPUS*NR_SLABS*L1_BYTES more memory use. Lets say NR_SLABS is 100 and a cache line size of 128 then we have just increased SLAB metadata requirements by 12.8k per cpu. (Another later patch reduces these requirements) Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* SLUB: direct pass through of page size or higher kmalloc requestsChristoph Lameter2007-10-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This gets rid of all kmalloc caches larger than page size. A kmalloc request larger than PAGE_SIZE > 2 is going to be passed through to the page allocator. This works both inline where we will call __get_free_pages instead of kmem_cache_alloc and in __kmalloc. kfree is modified to check if the object is in a slab page. If not then the page is freed via the page allocator instead. Roughly similar to what SLOB does. Advantages: - Reduces memory overhead for kmalloc array - Large kmalloc operations are faster since they do not need to pass through the slab allocator to get to the page allocator. - Performance increase of 10%-20% on alloc and 50% on free for PAGE_SIZEd allocations. SLUB must call page allocator for each alloc anyways since the higher order pages which that allowed avoiding the page alloc calls are not available in a reliable way anymore. So we are basically removing useless slab allocator overhead. - Large kmallocs yields page aligned object which is what SLAB did. Bad things like using page sized kmalloc allocations to stand in for page allocate allocs can be transparently handled and are not distinguishable from page allocator uses. - Checking for too large objects can be removed since it is done by the page allocator. Drawbacks: - No accounting for large kmalloc slab allocations anymore - No debugging of large kmalloc slab allocations. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* SLUB: Force inlining for functions in slub_def.hChristoph Lameter2007-08-31
| | | | | | | | | | Some compilers (especially older gcc releases) may skip inlining sometimes which will lead to link failures. Force the inlining of keyfunctions in slub_def.h to avoid these issues. Signed-off-by: Christoph Lameter <clameter@sgi.com> Acked-by: Jan Dittmer <jdi@l4x.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fix gfp_t annotations for slubAl Viro2007-07-20
| | | | | | | | Since we have use like ~SLUB_DMA, we ought to have the type set right in both cases. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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