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2012-05-02Merge 3.4-rc5 into driver-core-nextGreg Kroah-Hartman2-9/+10
This was done to resolve a merge issue with the init/main.c file. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-02ddr: add LPDDR2 data from JESD209-2Aneesh V3-0/+145
add LPDDR2 data from the JEDEC spec JESD209-2. The data includes: 1. Addressing information for LPDDR2 memories of different densities and types(S2/S4) 2. AC timing data. This data will useful for memory controller device drivers. Right now this is used by the TI EMIF SDRAM controller driver. Signed-off-by: Aneesh V <aneesh@ti.com> Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Reviewed-by: Benoit Cousson <b-cousson@ti.com> [santosh.shilimkar@ti.com: Moved to drivers/memory from drivers/misc] Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Tested-by: Lokesh Vutla <lokeshvutla@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-30dynamic_debug: init with early_initcall, not arch_initcallJim Cromie1-2/+2
1- Call dynamic_debug_init() from early_initcall, not arch_initcall. 2- Call dynamic_debug_init_debugfs() from fs_initcall, not module_init. RFC: This works for me on a 64 bit desktop and a i586 SBC, but is untested on other arches. I presume there is or was a reason original code used arch_initcall, maybe the constraints have changed. This makes facility available as soon as possible. 2nd change has a downside when dynamic_debug.verbose=1; all the vpr_info()s called in the proc-fs code are activated, causing voluminous output from dmesg. TBD: Im unsure of this explanation, but the output is there. This could be fixed by changing those callsites to v2pr_info(if verbose > 1). 1st change is still not early enough to enable pr_debugs in kernel/params, so parsing of boot-args isnt logged. The reparse of those args is however visible after params.dyndbg="+p" is processed. Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Acked-by: Jason Baron <jbaron@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-30dynamic_debug: update Documentation/*, Kconfig.debugJim Cromie1-6/+11
In dynamic-debug-howto.txt: - add section: Debug Messages at Module Initialization Time - update flags indicators in example outputs to include '=' - make flags descriptions tabular - add item on '_' flag-char - add dyndbg, boot-args examples - rewrap some paragraphs with long lines In Kconfig.debug, note that compiling with -DDEBUG enables all pr_debug()s in that code. In kernel-parameters.txt, add dyndbg and module.dyndbg items, and deprecate ddebug_query. Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Acked-by: Jason Baron <jbaron@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-30dynamic_debug: add modname arg to exec_query callchainJim Cromie1-8/+13
Pass module name into ddebug_exec_queries(), ddebug_exec_query(), and ddebug_parse_query() as separate parameter. In ddebug_parse_query(), the module name is added into the query struct before the query-string is parsed. This allows the query-string to be shorter: instead of: $modname.dyndbg="module $modname +fp" do this: $modname.dyndbg="+fp" Omitting "module $modname" from the query string is actually required for $modname.dyndbg rules; the set-only-once check added in a previous patch will throw an error if its added again. ddebug_query="..." has no $modname associated with it, so the query string may include it. This also fixes redundant "module $modname" otherwise needed to handle multiple queries per string: $modname.dyndbg="func foo +fp; func bar +fp" Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Acked-by: Jason Baron <jbaron@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-30dynamic_debug: print ram usage by ddebug tables if verboseJim Cromie1-1/+11
Print ram usage of dynamic-debug tables and verbose section so user knows cost of enabling CONFIG_DYNAMIC_DEBUG. This only counts the size of the _ddebug tables for builtins and the __verbose section that they refer to, not those used in loadable modules. Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Acked-by: Jason Baron <jbaron@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-30dynamic_debug: simplify dynamic_debug_init error exitJim Cromie1-11/+8
We dont want errors while parsing ddebug_query to unload ddebug tables, so set success after tables are loaded, and return 0 after query parsing is done. Simplify error handling code since its no longer used for success, and change goto label to out_err to clarify this. Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Acked-by: Jason Baron <jbaron@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-30dynamic_debug: combine parse_args callbacks togetherJim Cromie1-16/+20
Refactor ddebug_dyndbg_boot_param_cb and ddebug_dyndbg_module_param_cb into a common helper function, and call it from both. The handling of foo.dyndbg is unneeded by the latter, but harmless. The 2 callers differ only by pr_info and the return code they pass to the helper for when an unknown param is handled. I could slightly reduce dmesg clutter by putting the vpr_info in the common helper, after the return on_err, but that loses __func__ context, is overly silent on module_cb unknown param errors, and the clutter is only when dynamic_debug.verbose=1 anyway. Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Acked-by: Jason Baron <jbaron@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-30dynamic_debug: deprecate ddebug_query, suggest dyndbg insteadJim Cromie1-0/+2
With ddebug_dyndbg_boot_params_cb() handling bare dyndbg params, we dont need ddebug_query param anymore. Add a warning when processing ddebug_query= param that it is deprecated, and to change it to dyndbg= Add a deprecation notice for v3.8 to feature-removal-schedule.txt, and add a suggested deprecation period of 3 releases to the header. Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Acked-by: Jason Baron <jbaron@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-30dynamic_debug: make dynamic-debug work for module initializationJim Cromie1-0/+49
This introduces a fake module param $module.dyndbg. Its based upon Thomas Renninger's $module.ddebug boot-time debugging patch from https://lkml.org/lkml/2010/9/15/397 The 'fake' module parameter is provided for all modules, whether or not they need it. It is not explicitly added to each module, but is implemented in callbacks invoked from parse_args. For builtin modules, dynamic_debug_init() now directly calls parse_args(..., &ddebug_dyndbg_boot_params_cb), to process the params undeclared in the modules, just after the ddebug tables are processed. While its slightly weird to reprocess the boot params, parse_args() is already called repeatedly by do_initcall_levels(). More importantly, the dyndbg queries (given in ddebug_query or dyndbg params) cannot be activated until after the ddebug tables are ready, and reusing parse_args is cleaner than doing an ad-hoc parse. This reparse would break options like inc_verbosity, but they probably should be params, like verbosity=3. ddebug_dyndbg_boot_params_cb() handles both bare dyndbg (aka: ddebug_query) and module-prefixed dyndbg params, and ignores all other parameters. For example, the following will enable pr_debug()s in 4 builtin modules, in the order given: dyndbg="module params +p; module aio +p" module.dyndbg=+p pci.dyndbg For loadable modules, parse_args() in load_module() calls ddebug_dyndbg_module_params_cb(). This handles bare dyndbg params as passed from modprobe, and errors on other unknown params. Note that modprobe reads /proc/cmdline, so "modprobe foo" grabs all foo.params, strips the "foo.", and passes these to the kernel. ddebug_dyndbg_module_params_cb() is again called for the unknown params; it handles dyndbg, and errors on others. The "doing" arg added previously contains the module name. For non CONFIG_DYNAMIC_DEBUG builds, the stub function accepts and ignores $module.dyndbg params, other unknowns get -ENOENT. If no param value is given (as in pci.dyndbg example above), "+p" is assumed, which enables all pr_debug callsites in the module. The dyndbg fake parameter is not shown in /sys/module/*/parameters, thus it does not use any resources. Changes to it are made via the control file. Also change pr_info in ddebug_exec_queries to vpr_info, no need to see it all the time. Signed-off-by: Jim Cromie <jim.cromie@gmail.com> CC: Thomas Renninger <trenn@suse.de> CC: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Jason Baron <jbaron@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-30dynamic_debug: replace if (verbose) pr_info with macro vpr_infoJim Cromie1-46/+35
Use vpr_info to declutter code, reduce indenting, and change one additional pr_info call in ddebug_exec_queries. Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Acked-by: Jason Baron <jbaron@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-24rcu: List-debug variants of rcu list routines.Dave Jones1-0/+22
* Make __list_add_rcu check the next->prev and prev->next pointers just like __list_add does. * Make list_del_rcu use __list_del_entry, which does the same checking at deletion time. Has been running for a week here without anything being tripped up, but it seems worth adding for completeness just in case something ever does corrupt those lists. Signed-off-by: Dave Jones <davej@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2012-04-23lib/kobject.c : Remove redundant check in create_diryan1-7/+5
create_dir is a static function used only in kobject_add_internal. There's no need to do check here, for kobject_add_internal will reject kobject with invalid name. Signed-off-by: Yan Hong <clouds.yan@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-20lib: add support for stmp-style devicesWolfram Sang3-0/+85
MX23/28 use IP cores which follow a register layout I have first seen on STMP3xxx SoCs. In this layout, every register actually has four u32: 1.) to store a value directly 2.) a SET register where every 1-bit sets the corresponding bit, others are unaffected 3.) same with a CLR register 4.) same with a TOG (toggle) register Also, the 2 MSBs in register 0 are always the same and can be used to reset the IP core. All this is strictly speaking not mach-specific (but IP core specific) and, thus, doesn't need to be in mach-mxs/include. At least mx6 also uses IP cores following this stmp-style. So: Introduce a stmp-style device, put the code and defines for that in a public place (lib/), and let drivers for stmp-style devices select that code. To avoid regressions and ease reviewing, the actual code is simply copied from mach-mxs. It definately wants updates, but those need a seperate patch series. Voila, mach dependency gone, reusable code introduced. Note that I didn't remove the duplicated code from mach-mxs yet, first the drivers have to be converted. Signed-off-by: Wolfram Sang <w.sang@pengutronix.de> Acked-by: Shawn Guo <shawn.guo@linaro.org> Acked-by: Dong Aisheng <dong.aisheng@linaro.org>
2012-04-19Revert "driver core: check start node in klist_iter_init_node"Greg Kroah-Hartman1-10/+4
This reverts commit a15d49fd3094cff90e5410ca454a870e0a722fe1 as that patch broke the build. Cc: Hannes Reinecke <hare@suse.de> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-18driver core: check start node in klist_iter_init_nodeHannes Reinecke1-4/+10
klist_iter_init_node() takes a node as a start argument. However, this node might not be valid anymore. This patch updates the klist_iter_init_node() and dependent functions to return an error if so. All calling functions have been audited to check for a return code here. Signed-off-by: Hannes Reinecke <hare@suse.de> Cc: Greg Kroah-Hartmann <gregkh@linuxfoundation.org> Cc: Kay Sievers <kay@vrfy.org> Cc: Stable Kernel <stable@kernel.org> Cc: Linux Kernel <linux-kernel@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-18debugobjects: Fill_pool() returns void nowDan Carpenter1-1/+1
There was a return missed in 1fda107d44 "debugobjects: Remove unused return value from fill_pool()". It makes gcc complain: lib/debugobjects.c: In function ‘fill_pool’: lib/debugobjects.c:98:4: warning: ‘return’ with a value, in function returning void [enabled by default] Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Link: http://lkml.kernel.org/r/20120418112810.GA2669@elgon.mountain Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2012-04-18mpi: Avoid using freed pointer in mpi_lshift_limbs()Jesper Juhl1-2/+3
At the start of the function we assign 'a->d' to 'ap'. Then we use the RESIZE_IF_NEEDED macro on 'a' - this may free 'a->d' and replace it with newly allocaetd storage. In that case, we'll be operating on freed memory further down in the function when we index into 'ap[]'. Since we don't actually need 'ap' until after the use of the RESIZE_IF_NEEDED macro we can just delay the assignment to it until after we've potentially resized, thus avoiding the issue. While I was there anyway I also changed the integer variable 'n' to be const. It might as well be since we only assign to it once and use it as a constant, and then the compiler will tell us if we ever assign to it in the future. Signed-off-by: Jesper Juhl <jj@chaosbits.net> Acked-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2012-04-12dma-debug: release free_entries_lock before saving stack traceJakub Kicinski1-5/+5
Saving stack trace can take a while and once the entry is allocated free_entries_lock is no longer needed. Signed-off-by: Jakub Kicinski <kubakici@wp.pl> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2012-04-11debugobjects: printk with irqs enabledThomas Gleixner1-1/+1
No point in keeping interrupts disabled here. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2012-04-11debugobjects: Remove unused return value from fill_pool()Thomas Gleixner1-4/+3
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2012-04-10kobject: provide more diagnostic info for kobject_add_internal() failuresDan Williams1-7/+7
1/ convert open-coded KERN_ERR+dump_stack() to WARN(), so that automated tools pick up this warning. 2/ include the 'child' and 'parent' kobject names. This information was useful for tracking down the case where scsi invoked device_del() on a parent object and subsequently invoked device_add() on a child. Now the warning looks like: kobject_add_internal failed for target8:0:16 (error: -2 parent: end_device-8:0:24) Pid: 2942, comm: scsi_scan_8 Not tainted 3.3.0-rc7-isci+ #2 Call Trace: [<ffffffff8125e551>] kobject_add_internal+0x1c1/0x1f3 [<ffffffff81075149>] ? trace_hardirqs_on+0xd/0xf [<ffffffff8125e659>] kobject_add_varg+0x41/0x50 [<ffffffff8125e723>] kobject_add+0x64/0x66 [<ffffffff8131124b>] device_add+0x12d/0x63a [<ffffffff8125e0ef>] ? kobject_put+0x4c/0x50 [<ffffffff8132f370>] scsi_sysfs_add_sdev+0x4e/0x28a [<ffffffff8132dce3>] do_scan_async+0x9c/0x145 Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: James Bottomley <JBottomley@parallels.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-03-30debug: Add CONFIG_READABLE_ASMAndi Kleen1-0/+9
Add a config option to disable various gcc compiler optimizations that make assembler listings much harder to read. This is everything that reorders code significantly or creates partial functions. This is mainly to keep kernel hackers sane. Signed-off-by: Andi Kleen <ak@linux.intel.com> Link: http://lkml.kernel.org/r/1332960678-11879-2-git-send-email-andi@firstfloor.org Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2012-03-29Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 updates from Ingo Molnar. This touches some non-x86 files due to the sanitized INLINE_SPIN_UNLOCK config usage. Fixed up trivial conflicts due to just header include changes (removing headers due to cpu_idle() merge clashing with the <asm/system.h> split). * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/apic/amd: Be more verbose about LVT offset assignments x86, tls: Off by one limit check x86/ioapic: Add io_apic_ops driver layer to allow interception x86/olpc: Add debugfs interface for EC commands x86: Merge the x86_32 and x86_64 cpu_idle() functions x86/kconfig: Remove CONFIG_TR=y from the defconfigs x86: Stop recursive fault in print_context_stack after stack overflow x86/io_apic: Move and reenable irq only when CONFIG_GENERIC_PENDING_IRQ=y x86/apic: Add separate apic_id_valid() functions for selected apic drivers locking/kconfig: Simplify INLINE_SPIN_UNLOCK usage x86/kconfig: Update defconfigs x86: Fix excessive MSR print out when show_msr is not specified
2012-03-28Merge branch 'akpm' (Andrew's patch-bomb)Linus Torvalds3-270/+188
Merge third batch of patches from Andrew Morton: - Some MM stragglers - core SMP library cleanups (on_each_cpu_mask) - Some IPI optimisations - kexec - kdump - IPMI - the radix-tree iterator work - various other misc bits. "That'll do for -rc1. I still have ~10 patches for 3.4, will send those along when they've baked a little more." * emailed from Andrew Morton <akpm@linux-foundation.org>: (35 commits) backlight: fix typo in tosa_lcd.c crc32: add help text for the algorithm select option mm: move hugepage test examples to tools/testing/selftests/vm mm: move slabinfo.c to tools/vm mm: move page-types.c from Documentation to tools/vm selftests/Makefile: make `run_tests' depend on `all' selftests: launch individual selftests from the main Makefile radix-tree: use iterators in find_get_pages* functions radix-tree: rewrite gang lookup using iterator radix-tree: introduce bit-optimized iterator fs/proc/namespaces.c: prevent crash when ns_entries[] is empty nbd: rename the nbd_device variable from lo to nbd pidns: add reboot_pid_ns() to handle the reboot syscall sysctl: use bitmap library functions ipmi: use locks on watchdog timeout set on reboot ipmi: simplify locking ipmi: fix message handling during panics ipmi: use a tasklet for handling received messages ipmi: increase KCS timeouts ipmi: decrease the IPMI message transaction time in interrupt mode ...
2012-03-28crc32: add help text for the algorithm select optionDarrick J. Wong1-0/+4
Add help text to the crc32 algorithm selection option in Kconfig. Signed-off-by: Darrick J. Wong <djwong@us.ibm.com> Reported-by: Stefan Richter <stefanr@s5r6.in-berlin.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-28radix-tree: rewrite gang lookup using iteratorKonstantin Khlebnikov1-258/+33
Rewrite radix_tree_gang_lookup_* functions using the new radix-tree iterator. Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Tested-by: Hugh Dickins <hughd@google.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-28radix-tree: introduce bit-optimized iteratorKonstantin Khlebnikov1-0/+151
A series of radix tree cleanups, and usage of them in the core pagecache code. Micro-benchmark: lookup 14 slots (typical page-vector size) in radix-tree there earch <step> slot filled and tagged before/after - nsec per full scan through tree * Intel Sandy Bridge i7-2620M 4Mb L3 New code always faster * AMD Athlon 6000+ 2x1Mb L2, without L3 New code generally faster, Minor degradation (marked with "*") for huge sparse trees * i386 on Sandy Bridge New code faster for common cases: tagged and dense trees. Some degradations for non-tagged lookup on sparse trees. Ideally, there might help __ffs() analog for searching first non-zero long element in array, gcc sometimes cannot optimize this loop corretly. Numbers: CPU: Intel Sandy Bridge i7-2620M 4Mb L3 radix-tree with 1024 slots: tagged lookup step 1 before 7156 after 3613 step 2 before 5399 after 2696 step 3 before 4779 after 1928 step 4 before 4456 after 1429 step 5 before 4292 after 1213 step 6 before 4183 after 1052 step 7 before 4157 after 951 step 8 before 4016 after 812 step 9 before 3952 after 851 step 10 before 3937 after 732 step 11 before 4023 after 709 step 12 before 3872 after 657 step 13 before 3892 after 633 step 14 before 3720 after 591 step 15 before 3879 after 578 step 16 before 3561 after 513 normal lookup step 1 before 4266 after 3301 step 2 before 2695 after 2129 step 3 before 2083 after 1712 step 4 before 1801 after 1534 step 5 before 1628 after 1313 step 6 before 1551 after 1263 step 7 before 1475 after 1185 step 8 before 1432 after 1167 step 9 before 1373 after 1092 step 10 before 1339 after 1134 step 11 before 1292 after 1056 step 12 before 1319 after 1030 step 13 before 1276 after 1004 step 14 before 1256 after 987 step 15 before 1228 after 992 step 16 before 1247 after 999 radix-tree with 1024*1024*128 slots: tagged lookup step 1 before 1086102841 after 674196409 step 2 before 816839155 after 498138306 step 7 before 599728907 after 240676762 step 15 before 555729253 after 185219677 step 63 before 606637748 after 128585664 step 64 before 608384432 after 102945089 step 65 before 596987114 after 123996019 step 128 before 304459225 after 56783056 step 256 before 158846855 after 31232481 step 512 before 86085652 after 18950595 step 12345 before 6517189 after 1674057 normal lookup step 1 before 626064869 after 544418266 step 2 before 418809975 after 336321473 step 7 before 242303598 after 207755560 step 15 before 208380563 after 176496355 step 63 before 186854206 after 167283638 step 64 before 176188060 after 170143976 step 65 before 185139608 after 167487116 step 128 before 88181865 after 86913490 step 256 before 45733628 after 45143534 step 512 before 24506038 after 23859036 step 12345 before 2177425 after 2018662 * AMD Athlon 6000+ 2x1Mb L2, without L3 radix-tree with 1024 slots: tag-lookup step 1 before 8164 after 5379 step 2 before 5818 after 5581 step 3 before 4959 after 4213 step 4 before 4371 after 3386 step 5 before 4204 after 2997 step 6 before 4950 after 2744 step 7 before 4598 after 2480 step 8 before 4251 after 2288 step 9 before 4262 after 2243 step 10 before 4175 after 2131 step 11 before 3999 after 2024 step 12 before 3979 after 1994 step 13 before 3842 after 1929 step 14 before 3750 after 1810 step 15 before 3735 after 1810 step 16 before 3532 after 1660 normal-lookup step 1 before 7875 after 5847 step 2 before 4808 after 4071 step 3 before 4073 after 3462 step 4 before 3677 after 3074 step 5 before 4308 after 2978 step 6 before 3911 after 3807 step 7 before 3635 after 3522 step 8 before 3313 after 3202 step 9 before 3280 after 3257 step 10 before 3166 after 3083 step 11 before 3066 after 3026 step 12 before 2985 after 2982 step 13 before 2925 after 2924 step 14 before 2834 after 2808 step 15 before 2805 after 2803 step 16 before 2647 after 2622 radix-tree with 1024*1024*128 slots: tag-lookup step 1 before 1288059720 after 951736580 step 2 before 961292300 after 884212140 step 7 before 768905140 after 547267580 step 15 before 771319480 after 456550640 step 63 before 504847640 after 242704304 step 64 before 392484800 after 177920786 step 65 before 491162160 after 246895264 step 128 before 208084064 after 97348392 step 256 before 112401035 after 51408126 step 512 before 75825834 after 29145070 step 12345 before 5603166 after 2847330 normal-lookup step 1 before 1025677120 after 861375100 step 2 before 647220080 after 572258540 step 7 before 505518960 after 484041813 step 15 before 430483053 after 444815320 * step 63 before 388113453 after 404250546 * step 64 before 374154666 after 396027440 * step 65 before 381423973 after 396704853 * step 128 before 190078700 after 202619384 * step 256 before 100886756 after 102829108 * step 512 before 64074505 after 56158720 step 12345 before 4237289 after 4422299 * * i686 on Sandy bridge radix-tree with 1024 slots: tagged lookup step 1 before 7990 after 4019 step 2 before 5698 after 2897 step 3 before 5013 after 2475 step 4 before 4630 after 1721 step 5 before 4346 after 1759 step 6 before 4299 after 1556 step 7 before 4098 after 1513 step 8 before 4115 after 1222 step 9 before 3983 after 1390 step 10 before 4077 after 1207 step 11 before 3921 after 1231 step 12 before 3894 after 1116 step 13 before 3840 after 1147 step 14 before 3799 after 1090 step 15 before 3797 after 1059 step 16 before 3783 after 745 normal lookup step 1 before 5103 after 3499 step 2 before 3299 after 2550 step 3 before 2489 after 2370 step 4 before 2034 after 2302 * step 5 before 1846 after 2268 * step 6 before 1752 after 2249 * step 7 before 1679 after 2164 * step 8 before 1627 after 2153 * step 9 before 1542 after 2095 * step 10 before 1479 after 2109 * step 11 before 1469 after 2009 * step 12 before 1445 after 2039 * step 13 before 1411 after 2013 * step 14 before 1374 after 2046 * step 15 before 1340 after 1975 * step 16 before 1331 after 2000 * radix-tree with 1024*1024*128 slots: tagged lookup step 1 before 1225865377 after 667153553 step 2 before 842427423 after 471533007 step 7 before 609296153 after 276260116 step 15 before 544232060 after 226859105 step 63 before 519209199 after 141343043 step 64 before 588980279 after 141951339 step 65 before 521099710 after 138282060 step 128 before 298476778 after 83390628 step 256 before 149358342 after 43602609 step 512 before 76994713 after 22911077 step 12345 before 5328666 after 1472111 normal lookup step 1 before 819284564 after 533635310 step 2 before 512421605 after 364956155 step 7 before 271443305 after 305721345 * step 15 before 223591630 after 273960216 * step 63 before 190320247 after 217770207 * step 64 before 178538168 after 267411372 * step 65 before 186400423 after 215347937 * step 128 before 88106045 after 140540612 * step 256 before 44812420 after 70660377 * step 512 before 24435438 after 36328275 * step 12345 before 2123924 after 2148062 * bloat-o-meter delta for this patchset + patchset with related shmem cleanups bloat-o-meter: x86_64 add/remove: 4/3 grow/shrink: 5/6 up/down: 928/-939 (-11) function old new delta radix_tree_next_chunk - 499 +499 shmem_unuse 428 554 +126 shmem_radix_tree_replace 131 227 +96 find_get_pages_tag 354 419 +65 find_get_pages_contig 345 407 +62 find_get_pages 362 396 +34 __kstrtab_radix_tree_next_chunk - 22 +22 __ksymtab_radix_tree_next_chunk - 16 +16 __kcrctab_radix_tree_next_chunk - 8 +8 radix_tree_gang_lookup_slot 204 203 -1 static.shmem_xattr_set 384 381 -3 radix_tree_gang_lookup_tag_slot 208 191 -17 radix_tree_gang_lookup 231 187 -44 radix_tree_gang_lookup_tag 247 199 -48 shmem_unlock_mapping 278 190 -88 __lookup 217 - -217 __lookup_tag 242 - -242 radix_tree_locate_item 279 - -279 bloat-o-meter: i386 add/remove: 3/3 grow/shrink: 8/9 up/down: 1075/-1275 (-200) function old new delta radix_tree_next_chunk - 757 +757 shmem_unuse 352 449 +97 find_get_pages_contig 269 322 +53 shmem_radix_tree_replace 113 154 +41 find_get_pages_tag 277 318 +41 dcache_dir_lseek 426 458 +32 __kstrtab_radix_tree_next_chunk - 22 +22 vc_do_resize 968 977 +9 snd_pcm_lib_read1 725 733 +8 __ksymtab_radix_tree_next_chunk - 8 +8 netlbl_cipsov4_list 1120 1127 +7 find_get_pages 293 291 -2 new_slab 467 459 -8 bitfill_unaligned_rev 425 417 -8 radix_tree_gang_lookup_tag_slot 177 146 -31 blk_dump_cmd 267 229 -38 radix_tree_gang_lookup_slot 212 134 -78 shmem_unlock_mapping 221 128 -93 radix_tree_gang_lookup_tag 275 162 -113 radix_tree_gang_lookup 255 126 -129 __lookup 227 - -227 __lookup_tag 271 - -271 radix_tree_locate_item 277 - -277 This patch: Implement a clean, simple and effective radix-tree iteration routine. Iterating divided into two phases: * lookup next chunk in radix-tree leaf node * iterating through slots in this chunk Main iterator function radix_tree_next_chunk() returns pointer to first slot, and stores in the struct radix_tree_iter index of next-to-last slot. For tagged-iterating it also constuct bitmask of tags for retunted chunk. All additional logic implemented as static-inline functions and macroses. Also adds radix_tree_find_next_bit() static-inline variant of find_next_bit() optimized for small constant size arrays, because find_next_bit() too heavy for searching in an array with one/two long elements. [akpm@linux-foundation.org: rework comments a bit] Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Tested-by: Hugh Dickins <hughd@google.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-28lib/cpumask.c: remove __any_online_cpu()Srivatsa S. Bhat1-12/+0
__any_online_cpu() is not optimal and also unnecessary. So, replace its use by faster cpumask_* operations. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Venkatesh Pallipadi <venki@google.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-28Merge tag 'split-asm_system_h-for-linus-20120328' of ↵Linus Torvalds2-2/+1
git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system Pull "Disintegrate and delete asm/system.h" from David Howells: "Here are a bunch of patches to disintegrate asm/system.h into a set of separate bits to relieve the problem of circular inclusion dependencies. I've built all the working defconfigs from all the arches that I can and made sure that they don't break. The reason for these patches is that I recently encountered a circular dependency problem that came about when I produced some patches to optimise get_order() by rewriting it to use ilog2(). This uses bitops - and on the SH arch asm/bitops.h drags in asm-generic/get_order.h by a circuituous route involving asm/system.h. The main difficulty seems to be asm/system.h. It holds a number of low level bits with no/few dependencies that are commonly used (eg. memory barriers) and a number of bits with more dependencies that aren't used in many places (eg. switch_to()). These patches break asm/system.h up into the following core pieces: (1) asm/barrier.h Move memory barriers here. This already done for MIPS and Alpha. (2) asm/switch_to.h Move switch_to() and related stuff here. (3) asm/exec.h Move arch_align_stack() here. Other process execution related bits could perhaps go here from asm/processor.h. (4) asm/cmpxchg.h Move xchg() and cmpxchg() here as they're full word atomic ops and frequently used by atomic_xchg() and atomic_cmpxchg(). (5) asm/bug.h Move die() and related bits. (6) asm/auxvec.h Move AT_VECTOR_SIZE_ARCH here. Other arch headers are created as needed on a per-arch basis." Fixed up some conflicts from other header file cleanups and moving code around that has happened in the meantime, so David's testing is somewhat weakened by that. We'll find out anything that got broken and fix it.. * tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system: (38 commits) Delete all instances of asm/system.h Remove all #inclusions of asm/system.h Add #includes needed to permit the removal of asm/system.h Move all declarations of free_initmem() to linux/mm.h Disintegrate asm/system.h for OpenRISC Split arch_align_stack() out from asm-generic/system.h Split the switch_to() wrapper out of asm-generic/system.h Move the asm-generic/system.h xchg() implementation to asm-generic/cmpxchg.h Create asm-generic/barrier.h Make asm-generic/cmpxchg.h #include asm-generic/cmpxchg-local.h Disintegrate asm/system.h for Xtensa Disintegrate asm/system.h for Unicore32 [based on ver #3, changed by gxt] Disintegrate asm/system.h for Tile Disintegrate asm/system.h for Sparc Disintegrate asm/system.h for SH Disintegrate asm/system.h for Score Disintegrate asm/system.h for S390 Disintegrate asm/system.h for PowerPC Disintegrate asm/system.h for PA-RISC Disintegrate asm/system.h for MN10300 ...
2012-03-28Remove all #inclusions of asm/system.hDavid Howells2-2/+0
Remove all #inclusions of asm/system.h preparatory to splitting and killing it. Performed with the following command: perl -p -i -e 's!^#\s*include\s*<asm/system[.]h>.*\n!!' `grep -Irl '^#\s*include\s*<asm/system[.]h>' *` Signed-off-by: David Howells <dhowells@redhat.com>
2012-03-28Disintegrate asm/system.h for PowerPCDavid Howells1-0/+1
Disintegrate asm/system.h for PowerPC. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> cc: linuxppc-dev@lists.ozlabs.org
2012-03-27Merge branch 'for-linus-3.4-rc1' of ↵Linus Torvalds1-0/+5
git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml Pull UML changes from Richard Weinberger: "Mostly bug fixes and cleanups" * 'for-linus-3.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml: (35 commits) um: Update defconfig um: Switch to large mcmodel on x86_64 MTD: Relax dependencies um: Wire CONFIG_GENERIC_IO up um: Serve io_remap_pfn_range() Introduce CONFIG_GENERIC_IO um: allow SUBARCH=x86 um: most of the SUBARCH uses can be killed um: deadlock in line_write_interrupt() um: don't bother trying to rebuild CHECKFLAGS for USER_OBJS um: use the right ifdef around exports in user_syms.c um: a bunch of headers can be killed by using generic-y um: ptrace-generic.h doesn't need user.h um: kill HOST_TASK_PID um: remove pointless include of asm/fixmap.h from asm/pgtable.h um: asm-offsets.h might as well come from underlying arch... um: merge processor_{32,64}.h a bit... um: switch close_chan() to struct line um: race fix: initialize delayed_work *before* registering IRQ um: line->have_irq is never checked... ...
2012-03-25Introduce CONFIG_GENERIC_IORichard Weinberger1-0/+5
There are situations where CONFIG_HAS_IOMEM is too restrictive. For example CONFIG_MTD_NAND_NANDSIM depends on CONFIG_HAS_IOMEM but it works perfectly fine if an architecture without io memory just includes asm-generic/io.h or implements everything defined in it. UML is such a corner case. Signed-off-by: Richard Weinberger <richard@nod.at>
2012-03-24Merge tag 'module-for-3.4' of ↵Linus Torvalds63-63/+71
git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux Pull cleanup of fs/ and lib/ users of module.h from Paul Gortmaker: "Fix up files in fs/ and lib/ dirs to only use module.h if they really need it. These are trivial in scope vs the work done previously. We now have things where any few remaining cleanups can be farmed out to arch or subsystem maintainers, and I have done so when possible. What is remaining here represents the bits that don't clearly lie within a single arch/subsystem boundary, like the fs dir and the lib dir. Some duplicate includes arising from overlapping fixes from independent subsystem maintainer submissions are also quashed." Fix up trivial conflicts due to clashes with other include file cleanups (including some due to the previous bug.h cleanup pull). * tag 'module-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: lib: reduce the use of module.h wherever possible fs: reduce the use of module.h wherever possible includecheck: delete any duplicate instances of module.h
2012-03-24Merge tag 'bug-for-3.4' of ↵Linus Torvalds8-0/+9
git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux Pull <linux/bug.h> cleanup from Paul Gortmaker: "The changes shown here are to unify linux's BUG support under the one <linux/bug.h> file. Due to historical reasons, we have some BUG code in bug.h and some in kernel.h -- i.e. the support for BUILD_BUG in linux/kernel.h predates the addition of linux/bug.h, but old code in kernel.h wasn't moved to bug.h at that time. As a band-aid, kernel.h was including <asm/bug.h> to pseudo link them. This has caused confusion[1] and general yuck/WTF[2] reactions. Here is an example that violates the principle of least surprise: CC lib/string.o lib/string.c: In function 'strlcat': lib/string.c:225:2: error: implicit declaration of function 'BUILD_BUG_ON' make[2]: *** [lib/string.o] Error 1 $ $ grep linux/bug.h lib/string.c #include <linux/bug.h> $ We've included <linux/bug.h> for the BUG infrastructure and yet we still get a compile fail! [We've not kernel.h for BUILD_BUG_ON.] Ugh - very confusing for someone who is new to kernel development. With the above in mind, the goals of this changeset are: 1) find and fix any include/*.h files that were relying on the implicit presence of BUG code. 2) find and fix any C files that were consuming kernel.h and hence relying on implicitly getting some/all BUG code. 3) Move the BUG related code living in kernel.h to <linux/bug.h> 4) remove the asm/bug.h from kernel.h to finally break the chain. During development, the order was more like 3-4, build-test, 1-2. But to ensure that git history for bisect doesn't get needless build failures introduced, the commits have been reorderd to fix the problem areas in advance. [1] https://lkml.org/lkml/2012/1/3/90 [2] https://lkml.org/lkml/2012/1/17/414" Fix up conflicts (new radeon file, reiserfs header cleanups) as per Paul and linux-next. * tag 'bug-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: kernel.h: doesn't explicitly use bug.h, so don't include it. bug: consolidate BUILD_BUG_ON with other bug code BUG: headers with BUG/BUG_ON etc. need linux/bug.h bug.h: add include of it to various implicit C users lib: fix implicit users of kernel.h for TAINT_WARN spinlock: macroize assert_spin_locked to avoid bug.h dependency x86: relocate get/set debugreg fcns to include/asm/debugreg.
2012-03-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/sysctlLinus Torvalds1-8/+0
Pull sysctl updates from Eric Biederman: - Rewrite of sysctl for speed and clarity. Insert/remove/Lookup in sysctl are all now O(NlogN) operations, and are no longer bottlenecks in the process of adding and removing network devices. sysctl is now focused on being a filesystem instead of system call and the code can all be found in fs/proc/proc_sysctl.c. Hopefully this means the code is now approachable. Much thanks is owed to Lucian Grinjincu for keeping at this until something was found that was usable. - The recent proc_sys_poll oops found by the fuzzer during hibernation is fixed. * git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/sysctl: (36 commits) sysctl: protect poll() in entries that may go away sysctl: Don't call sysctl_follow_link unless we are a link. sysctl: Comments to make the code clearer. sysctl: Correct error return from get_subdir sysctl: An easier to read version of find_subdir sysctl: fix memset parameters in setup_sysctl_set() sysctl: remove an unused variable sysctl: Add register_sysctl for normal sysctl users sysctl: Index sysctl directories with rbtrees. sysctl: Make the header lists per directory. sysctl: Move sysctl_check_dups into insert_header sysctl: Modify __register_sysctl_paths to take a set instead of a root and an nsproxy sysctl: Replace root_list with links between sysctl_table_sets. sysctl: Add sysctl_print_dir and use it in get_subdir sysctl: Stop requiring explicit management of sysctl directories sysctl: Add a root pointer to ctl_table_set sysctl: Rewrite proc_sys_readdir in terms of first_entry and next_entry sysctl: Rewrite proc_sys_lookup introducing find_entry and lookup_entry. sysctl: Normalize the root_table data structure. sysctl: Factor out insert_header and erase_header ...
2012-03-23procfs: add num_to_str() to speed up /proc/statKAMEZAWA Hiroyuki1-0/+20
== stat_check.py num = 0 with open("/proc/stat") as f: while num < 1000 : data = f.read() f.seek(0, 0) num = num + 1 == perf shows 20.39% stat_check.py [kernel.kallsyms] [k] format_decode 13.41% stat_check.py [kernel.kallsyms] [k] number 12.61% stat_check.py [kernel.kallsyms] [k] vsnprintf 10.85% stat_check.py [kernel.kallsyms] [k] memcpy 4.85% stat_check.py [kernel.kallsyms] [k] radix_tree_lookup 4.43% stat_check.py [kernel.kallsyms] [k] seq_printf This patch removes most of calls to vsnprintf() by adding num_to_str() and seq_print_decimal_ull(), which prints decimal numbers without rich functions provided by printf(). On my 8cpu box. == Before patch == [root@bluextal test]# time ./stat_check.py real 0m0.150s user 0m0.026s sys 0m0.121s == After patch == [root@bluextal test]# time ./stat_check.py real 0m0.055s user 0m0.022s sys 0m0.030s [akpm@linux-foundation.org: remove incorrect comment, use less statck in num_to_str(), move comment from .h to .c, simplify seq_put_decimal_ull()] [andrea@betterlinux.com: avoid breaking the ABI in /proc/stat] Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrea Righi <andrea@betterlinux.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Glauber Costa <glommer@parallels.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Turner <pjt@google.com> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-23crc32: select an algorithm via KconfigDarrick J. Wong2-0/+61
Allow the kernel builder to choose a crc32* algorithm for the kernel. Signed-off-by: Darrick J. Wong <djwong@us.ibm.com> Cc: Bob Pearson <rpearson@systemfabricworks.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-23crc32: add self-test code for crc32cDarrick J. Wong1-102/+261
Add self-test code for crc32c. Signed-off-by: Darrick J. Wong <djwong@us.ibm.com> Cc: Bob Pearson <rpearson@systemfabricworks.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-23crc32: bolt on crc32cDarrick J. Wong4-34/+95
Reuse the existing crc32 code to stamp out a crc32c implementation. Signed-off-by: Darrick J. Wong <djwong@us.ibm.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Bob Pearson <rpearson@systemfabricworks.com> Cc: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-23crc32: add note about this patchset to crc32.cBob Pearson1-0/+4
Add a comment at the top of crc32.c [djwong@us.ibm.com: Minor changelog tweaks] Signed-off-by: Bob Pearson <rpearson@systemfabricworks.com> Signed-off-by: Darrick J. Wong <djwong@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-23crc32: optimize loop counter for x86Bob Pearson1-0/+13
Add two changes that improve the performance of x86 systems 1. replace main loop with incrementing counter this change improves the performance of the selftest by about 5-6% on Nehalem CPUs. The apparent reason is that the compiler can use the loop index to perform an indexed memory access. This is reported to make the performance of PowerPC CPUs to get worse. 2. replace the rem_len loop with incrementing counter this change improves the performance of the selftest, which has more than the usual number of occurances, by about 1-2% on x86 CPUs. In actual work loads the length is most often a multiple of 4 bytes and this code does not get executed as often if at all. Again this change is reported to make the performance of PowerPC get worse. [djwong@us.ibm.com: Minor changelog tweaks] Signed-off-by: Bob Pearson <rpearson@systemfabricworks.com> Signed-off-by: Darrick J. Wong <djwong@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-23crc32: add slice-by-8 algorithm to existing codeBob Pearson3-35/+75
Add slicing-by-8 algorithm to the existing slicing-by-4 algorithm. This consists of: - extend largest BITS size from 32 to 64 - extend tables from tab[4][256] to up to tab[8][256] - Add code for inner loop. [djwong@us.ibm.com: Minor changelog tweaks] Signed-off-by: Bob Pearson <rpearson@systemfabricworks.com> Signed-off-by: Darrick J. Wong <djwong@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-23crc32: make CRC_*_BITS definition correspond to actual bit countsBob Pearson3-12/+34
crc32.c provides a choice of one of several algorithms for computing the LSB and LSB versions of the CRC32 checksum based on the parameters CRC_LE_BITS and CRC_BE_BITS. In the original version the values 1, 2, 4 and 8 respectively selected versions of the alrogithm that computed the crc 1, 2, 4 and 32 bits as a time. This patch series adds a new version that computes the CRC 64 bits at a time. To make things easier to understand the parameter has been reinterpreted to actually stand for the number of bits processed in each step of the algorithm so that the old value 8 has been replaced with the value 32. This also allows us to add in a widely used crc algorithm that computes the crc 8 bits at a time called the Sarwate algorithm. [djwong@us.ibm.com: Minor changelog tweaks] Signed-off-by: Bob Pearson <rpearson@systemfabricworks.com> Signed-off-by: Darrick J. Wong <djwong@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-23crc32: fix mixing of endian-specific typesBob Pearson1-6/+6
crc32.c in its original version freely mixed u32, __le32 and __be32 types which caused warnings from sparse with __CHECK_ENDIAN__. This patch fixes these by forcing the types to u32. [djwong@us.ibm.com: Minor changelog tweaks] Signed-off-by: Bob Pearson <rpearson@systemfabricworks.com> Signed-off-by: Darrick J. Wong <djwong@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-23crc32: miscellaneous cleanupsBob Pearson2-71/+39
Misc cleanup of lib/crc32.c and related files. - remove unnecessary header files. - straighten out some convoluted ifdef's - rewrite some references to 2 dimensional arrays as 1 dimensional arrays to make them correct. I.e. replace tab[i] with tab[0][i]. - a few trivial whitespace changes - fix a warning in gen_crc32tables.c caused by a mismatch in the type of the pointer passed to output table. Since the table is only used at kernel compile time, it is simpler to make the table big enough to hold the largest column size used. One cannot make the column size smaller in output_table because it has to be used by both the le and be tables and they can have different column sizes. [djwong@us.ibm.com: Minor changelog tweaks] Signed-off-by: Bob Pearson <rpearson@systemfabricworks.com> Signed-off-by: Darrick J. Wong <djwong@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-23crc32: simplify unit test codeBob Pearson2-117/+691
Replace the unit test provided in crc32.c, which doesn't have a makefile and doesn't compile with current headers, with a simpler self test routine that also gives a measure of performance and runs at module init time. The self test option can be enabled through a configuration option CONFIG_CRC32_SELFTEST. The test stresses the pre and post loops and is thus not very realistic since actual uses will likely have addresses and lengths that are at least 4 byte aligned. However, the main loop is long enough so that the performance is dominated by that loop. The expected values for crc32_le and crc32_be were generated with the original version of crc32.c using CRC_BITS_LE = 8 and CRC_BITS_BE = 8. These values were then used to check all the values of the BITS parameters in both the original and new versions. The performance results show some variability from run to run in spite of attempts to both warm the cache and reduce the amount of OS noise by limiting interrutps during the test. To get comparable results and to analyse options wrt performance the best time reported over a small sample of runs has been taken. [djwong@us.ibm.com: Minor changelog tweaks] Signed-off-by: Bob Pearson <rpearson@systemfabricworks.com> Signed-off-by: Darrick J. Wong <djwong@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-23crc32: move long comment about crc32 fundamentals to Documentation/Bob Pearson1-127/+2
Move a long comment from lib/crc32.c to Documentation/crc32.txt where it will more likely get read. Edited the resulting document to add an explanation of the slicing-by-n algorithm. [djwong@us.ibm.com: minor changelog tweaks] [akpm@linux-foundation.org: fix typo, per George] Signed-off-by: George Spelvin <linux@horizon.com> Signed-off-by: Bob Pearson <rpearson@systemfabricworks.com> Signed-off-by: Darrick J. Wong <djwong@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-23crc32: remove two instances of trailing whitespacesBob Pearson2-2/+2
This patchset (re)uses Bob Pearson's crc32 slice-by-8 code to stamp out a software crc32c implementation. It removes the crc32c implementation in crypto/ in favor of using the stamped-out one in lib/. There is also a change to Kconfig so that the kernel builder can pick an implementation best suited for the hardware. The motivation for this patchset is that I am working on adding full metadata checksumming to ext4. As far as performance impact of adding checksumming goes, I see nearly no change with a standard mail server ffsb simulation. On a test that involves only file creation and deletion and extent tree writes, I see a drop of about 50 pcercent with the current kernel crc32c implementation; this improves to a drop of about 20 percent with the enclosed crc32c code. When metadata is usually a small fraction of total IO, this new implementation doesn't help much because metadata is usually a small fraction of total IO. However, when we are doing IO that is almost all metadata (such as rm -rf'ing a tree), then this patch speeds up the operation substantially. Incidentally, given that iscsi, sctp, and btrfs also use crc32c, this patchset should improve their speed as well. I have not yet quantified that, however. This latest submission combines Bob's patches from late August 2011 with mine so that they can be one coherent patch set. Please excuse my inability to combine some of the patches; I've been advised to leave Bob's patches alone and build atop them instead. :/ Since the last posting, I've also collected some crc32c test results on a bunch of different x86/powerpc/sparc platforms. The results can be viewed here: http://goo.gl/sgt3i ; the "crc32-kern-le" and "crc32c" columns describe the performance of the kernel's current crc32 and crc32c software implementations. The "crc32c-by8-le" column shows crc32c performance with this patchset applied. I expect crc32 performance to be roughly the same. The two _boost columns at the right side of the spreadsheet shows how much faster the new implementation is over the old one. As you can see, crc32 rises substantially, and crc32c experiences a huge increase. This patch: - remove trailing whitespace from lib/crc32.c - remove trailing whitespace from lib/crc32defs.h [djwong@us.ibm.com: changelog tweaks] Signed-off-by: Bob Pearson <rpearson@systemfabricworks.com> Signed-off-by: Darrick J. Wong <djwong@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>