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2009-02-02modules: Use a better scheme for refcountingEric Dumazet
Current refcounting for modules (done if CONFIG_MODULE_UNLOAD=y) is using a lot of memory. Each 'struct module' contains an [NR_CPUS] array of full cache lines. This patch uses existing infrastructure (percpu_modalloc() & percpu_modfree()) to allocate percpu space for the refcount storage. Instead of wasting NR_CPUS*128 bytes (on i386), we now use nr_cpu_ids*sizeof(local_t) bytes. On a typical distro, where NR_CPUS=8, shiping 2000 modules, we reduce size of module files by about 2 Mbytes. (1Kb per module) Instead of having all refcounters in the same memory node - with TLB misses because of vmalloc() - this new implementation permits to have better NUMA properties, since each CPU will use storage on its preferred node, thanks to percpu storage. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-14[CVE-2009-0029] System call wrappers part 08Heiko Carstens
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-07async: Asynchronous function calls to speed up kernel bootArjan van de Ven
Right now, most of the kernel boot is strictly synchronous, such that various hardware delays are done sequentially. In order to make the kernel boot faster, this patch introduces infrastructure to allow doing some of the initialization steps asynchronously, which will hide significant portions of the hardware delays in practice. In order to not change device order and other similar observables, this patch does NOT do full parallel initialization. Rather, it operates more in the way an out of order CPU does; the work may be done out of order and asynchronous, but the observable effects (instruction retiring for the CPU) are still done in the original sequence. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
2009-01-06module: add MODULE_STATE_LIVE notifyMasami Hiramatsu
Add a module notifier call which notifies that the state of a module changes from MODULE_STATE_COMING to MODULE_STATE_LIVE. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06module: add within_module_core() and within_module_init()Masami Hiramatsu
This series of patches allows kprobes to probe module's __init and __exit functions. This means, you can probe driver initialization and terminating. Currently, kprobes can't probe __init function because these functions are freed after module initialization. And it also can't probe module __exit functions because kprobe increments reference count of target module and user can't unload it. this means __exit functions never be called unless removing probes from the module. To solve both cases, this series of patches introduces GONE flag and sets it when the target code is freed(for this purpose, kprobes hooks MODULE_STATE_* events). This also removes refcount incrementing for allowing user to unload target module. Users can check which probes are GONE by debugfs interface. For taking timing of freeing module's .init text, these also include a patch which adds module's notifier of MODULE_STATE_LIVE event. This patch: Add within_module_core() and within_module_init() for checking whether an address is in the module .init.text section or .text section, and replace within() local inline functions in kernel/module.c with them. kprobes uses these functions to check where the kprobe is inserted. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06Remove remaining unwinder codeAlexey Dobriyan
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Gabor Gombas <gombasg@sztaki.hu> Cc: Jan Beulich <jbeulich@novell.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Ingo Molnar <mingo@elte.hu>, Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-05module: convert to stop_machine_create/destroy.Heiko Carstens
The module code relies on a non-failing stop_machine call. So we create the kstop threads in advance and with that make sure the call won't fail. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-01-05module: fix module loading failure of large kernel modules for pariscHelge Deller
When creating the final layout of a kernel module in memory, allow the module loader to reserve some additional memory in front of a given section. This is currently only needed for the parisc port which needs to put the stub entries there to fulfill the 17/22bit PCREL relocations with large kernel modules like xfs. Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (renamed fn)
2009-01-05module: fix warning of unused function when !CONFIG_PROC_FSJianjun Kong
Fix this warning: kernel/module.c:824: warning: ‘print_unload_info’ defined but not used print_unload_info() just was used when CONFIG_PROC_FS was defined. This patch mark print_unload_info() inline to solve the problem. Signed-off-by: Jianjun Kong <jianjun@zeuux.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> CC: Ingo Molnar <mingo@elte.hu> CC: Américo Wang <xiyou.wangcong@gmail.com>
2009-01-05kernel/module.c: compare symbol values when marking symbols as exported in ↵Tim Abbott
/proc/kallsyms. When there are two symbols in a module with the same name, one of which is exported, both will be marked as exported in /proc/kallsyms. There aren't any instances of this in the current kernel, but it is easy to construct a simple module with two compilation units that exhibits the problem. $ objdump -j .text -t testmod.ko | grep foo 00000000 l F .text 00000032 foo 00000080 g F .text 00000001 foo $ sudo insmod testmod.ko $ grep "T foo" /proc/kallsyms c28e8000 T foo [testmod] c28e8080 T foo [testmod] Fix this by comparing the symbol values once we've found the exported symbol table entry matching the symbol name. Tested using Ksplice: $ ksplice-create --patch=this_commit.patch --id=bar . $ sudo ksplice-apply ksplice-bar.tar.gz Done! $ grep "T foo" /proc/kallsyms c28e8080 T foo [testmod] Signed-off-by: Tim Abbott <tabbott@mit.edu> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-12-08tracing/function-graph-tracer: introduce __notrace_funcgraph to filter ↵Frederic Weisbecker
special functions Impact: trace more functions When the function graph tracer is configured, three more files are not traced to prevent only four functions to be traced. And this impacts the normal function tracer too. arch/x86/kernel/process_64/32.c: I had crashes when I let this file traced. After some debugging, I saw that the "current" task point was changed inside__swtich_to(), ie: "write_pda(pcurrent, next_p);" inside process_64.c Since the tracer store the original return address of the function inside current, we had crashes. Only __switch_to() has to be excluded from tracing. kernel/module.c and kernel/extable.c: Because of a function used internally by the function graph tracer: __kernel_text_address() To let the other functions inside these files to be traced, this patch introduces the __notrace_funcgraph function prefix which is __notrace if function graph tracer is configured and nothing if not. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-17Merge branches 'tracing/branch-tracer', 'tracing/ftrace', ↵Ingo Molnar
'tracing/function-return-tracer', 'tracing/tracepoints' and 'tracing/urgent' into tracing/core
2008-11-16tracepoints: use modules notifiersMathieu Desnoyers
Impact: cleanup Use module notifiers for tracepoint updates rather than adding a hook in module.c. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-16markers: use module notifierMathieu Desnoyers
Impact: cleanup Use module notifiers instead of adding a hook in module.c. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-16ftrace: pass module struct to arch dynamic ftrace functionsSteven Rostedt
Impact: allow archs more flexibility on dynamic ftrace implementations Dynamic ftrace has largly been developed on x86. Since x86 does not have the same limitations as other architectures, the ftrace interaction between the generic code and the architecture specific code was not flexible enough to handle some of the issues that other architectures have. Most notably, module trampolines. Due to the limited branch distance that archs make in calling kernel core code from modules, the module load code must create a trampoline to jump to what will make the larger jump into core kernel code. The problem arises when this happens to a call to mcount. Ftrace checks all code before modifying it and makes sure the current code is what it expects. Right now, there is not enough information to handle modifying module trampolines. This patch changes the API between generic dynamic ftrace code and the arch dependent code. There is now two functions for modifying code: ftrace_make_nop(mod, rec, addr) - convert the code at rec->ip into a nop, where the original text is calling addr. (mod is the module struct if called by module init) ftrace_make_caller(rec, addr) - convert the code rec->ip that should be a nop into a caller to addr. The record "rec" now has a new field called "arch" where the architecture can add any special attributes to each call site record. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-23Merge branch 'proc' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/adobriyan/proc * 'proc' of git://git.kernel.org/pub/scm/linux/kernel/git/adobriyan/proc: (35 commits) proc: remove fs/proc/proc_misc.c proc: move /proc/vmcore creation to fs/proc/vmcore.c proc: move pagecount stuff to fs/proc/page.c proc: move all /proc/kcore stuff to fs/proc/kcore.c proc: move /proc/schedstat boilerplate to kernel/sched_stats.h proc: move /proc/modules boilerplate to kernel/module.c proc: move /proc/diskstats boilerplate to block/genhd.c proc: move /proc/zoneinfo boilerplate to mm/vmstat.c proc: move /proc/vmstat boilerplate to mm/vmstat.c proc: move /proc/pagetypeinfo boilerplate to mm/vmstat.c proc: move /proc/buddyinfo boilerplate to mm/vmstat.c proc: move /proc/vmallocinfo to mm/vmalloc.c proc: move /proc/slabinfo boilerplate to mm/slub.c, mm/slab.c proc: move /proc/slab_allocators boilerplate to mm/slab.c proc: move /proc/interrupts boilerplate code to fs/proc/interrupts.c proc: move /proc/stat to fs/proc/stat.c proc: move rest of /proc/partitions code to block/genhd.c proc: move /proc/cpuinfo code to fs/proc/cpuinfo.c proc: move /proc/devices code to fs/proc/devices.c proc: move rest of /proc/locks to fs/locks.c ...
2008-10-23proc: move /proc/modules boilerplate to kernel/module.cAlexey Dobriyan
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
2008-10-22Remove stop_machine during module load v2Andi Kleen
Remove stop_machine during module load v2 module loading currently does a stop_machine on each module load to insert the module into the global module lists. Especially on larger systems this can be quite expensive. It does that to handle concurrent lock lessmodule list readers like kallsyms. I don't think stop_machine() is actually needed to insert something into a list though. There are no concurrent writers because the module mutex is taken. And the RCU list functions know how to insert a node into a list with the right memory ordering so that concurrent readers don't go off into the wood. So remove the stop_machine for the module list insert and just do a list_add_rcu() instead. Module removal will still do a stop_machine of course, it needs that for other reasons. v2: Revised readers based on Paul's comments. All readers that only rely on disabled preemption need to be changed to list_for_each_rcu(). Done that. The others are ok because they have the modules mutex. Also added a possible missing preempt disable for print_modules(). [cc Paul McKenney for review. It's not RCU, but quite similar.] Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-10-22module: simplify load_module.Rusty Russell
Linus' recent catch of stack overflow in load_module lead me to look at the code. A couple of helpers to get a section address and get objects from a section can help clean things up a little. (And in case you're wondering, the stack size also dropped from 328 to 284 bytes). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-10-20Merge branch 'tracing-v28-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'tracing-v28-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (131 commits) tracing/fastboot: improve help text tracing/stacktrace: improve help text tracing/fastboot: fix initcalls disposition in bootgraph.pl tracing/fastboot: fix bootgraph.pl initcall name regexp tracing/fastboot: fix issues and improve output of bootgraph.pl tracepoints: synchronize unregister static inline tracepoints: tracepoint_synchronize_unregister() ftrace: make ftrace_test_p6nop disassembler-friendly markers: fix synchronize marker unregister static inline tracing/fastboot: add better resolution to initcall debug/tracing trace: add build-time check to avoid overrunning hex buffer ftrace: fix hex output mode of ftrace tracing/fastboot: fix initcalls disposition in bootgraph.pl tracing/fastboot: fix printk format typo in boot tracer ftrace: return an error when setting a nonexistent tracer ftrace: make some tracers reentrant ring-buffer: make reentrant ring-buffer: move page indexes into page headers tracing/fastboot: only trace non-module initcalls ftrace: move pc counter in irqtrace ... Manually fix conflicts: - init/main.c: initcall tracing - kernel/module.c: verbose level vs tracepoints - scripts/bootgraph.pl: fallout from cherry-picking commits.
2008-10-17Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging-2.6: (25 commits) staging: at76_usb wireless driver Staging: workaround build system bug Staging: Lindent sxg.c Staging: SLICOSS: Call pci_release_regions at driver exit Staging: SLICOSS: Fix remaining type names Staging: SLICOSS: Fix warnings due to static usage Staging: SLICOSS: lots of checkpatch fixes Staging: go7007 v4l fixes Staging: Fix gcc warnings in sxg Staging: add echo cancelation module Staging: add wlan-ng prism2 usb driver Staging: add w35und wifi driver Staging: USB/IP: add host driver Staging: USB/IP: add client driver Staging: USB/IP: add common functions needed Staging: add the go7007 video driver Staging: add me4000 pci data collection driver Staging: add me4000 firmware files Staging: add sxg network driver Staging: add Alacritech slicoss network driver ... Fixed up conflicts due to taint flags changes and MAINTAINERS cleanup in MAINTAINERS, include/linux/kernel.h and kernel/panic.c.
2008-10-16Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6: (46 commits) UIO: Fix mapping of logical and virtual memory UIO: add automata sercos3 pci card support UIO: Change driver name of uio_pdrv UIO: Add alignment warnings for uio-mem Driver core: add bus_sort_breadthfirst() function NET: convert the phy_device file to use bus_find_device_by_name kobject: Cleanup kobject_rename and !CONFIG_SYSFS kobject: Fix kobject_rename and !CONFIG_SYSFS sysfs: Make dir and name args to sysfs_notify() const platform: add new device registration helper sysfs: use ilookup5() instead of ilookup5_nowait() PNP: create device attributes via default device attributes Driver core: make bus_find_device_by_name() more robust usb: turn dev_warn+WARN_ON combos into dev_WARN debug: use dev_WARN() rather than WARN_ON() in device_pm_add() debug: Introduce a dev_WARN() function sysfs: fix deadlock device model: Do a quickcheck for driver binding before doing an expensive check Driver core: Fix cleanup in device_create_vargs(). Driver core: Clarify device cleanup. ...
2008-10-16Make the taint flags reliableAndi Kleen
It's somewhat unlikely that it happens, but right now a race window between interrupts or machine checks or oopses could corrupt the tainted bitmap because it is modified in a non atomic fashion. Convert the taint variable to an unsigned long and use only atomic bit operations on it. Unfortunately this means the intvec sysctl functions cannot be used on it anymore. It turned out the taint sysctl handler could actually be simplified a bit (since it only increases capabilities) so this patch actually removes code. [akpm@linux-foundation.org: remove unneeded include] Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16driver core: basic infrastructure for per-module dynamic debug messagesJason Baron
Base infrastructure to enable per-module debug messages. I've introduced CONFIG_DYNAMIC_PRINTK_DEBUG, which when enabled centralizes control of debugging statements on a per-module basis in one /proc file, currently, <debugfs>/dynamic_printk/modules. When, CONFIG_DYNAMIC_PRINTK_DEBUG, is not set, debugging statements can still be enabled as before, often by defining 'DEBUG' for the proper compilation unit. Thus, this patch set has no affect when CONFIG_DYNAMIC_PRINTK_DEBUG is not set. The infrastructure currently ties into all pr_debug() and dev_dbg() calls. That is, if CONFIG_DYNAMIC_PRINTK_DEBUG is set, all pr_debug() and dev_dbg() calls can be dynamically enabled/disabled on a per-module basis. Future plans include extending this functionality to subsystems, that define their own debug levels and flags. Usage: Dynamic debugging is controlled by the debugfs file, <debugfs>/dynamic_printk/modules. This file contains a list of the modules that can be enabled. The format of the file is as follows: <module_name> <enabled=0/1> . . . <module_name> : Name of the module in which the debug call resides <enabled=0/1> : whether the messages are enabled or not For example: snd_hda_intel enabled=0 fixup enabled=1 driver enabled=0 Enable a module: $echo "set enabled=1 <module_name>" > dynamic_printk/modules Disable a module: $echo "set enabled=0 <module_name>" > dynamic_printk/modules Enable all modules: $echo "set enabled=1 all" > dynamic_printk/modules Disable all modules: $echo "set enabled=0 all" > dynamic_printk/modules Finally, passing "dynamic_printk" at the command line enables debugging for all modules. This mode can be turned off via the above disable command. [gkh: minor cleanups and tweaks to make the build work quietly] Signed-off-by: Jason Baron <jbaron@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-10-16modules: fix module "notes" kobject leakAlexey Dobriyan
Fix "notes" kobject leak It happens every rmmod if KALLSYMS=y and SYSFS=y. # modprobe foo kobject: 'foo' (ffffffffa00743d0): kobject_add_internal: parent: 'module', set: 'module' kobject: 'holders' (ffff88017e7c5770): kobject_add_internal: parent: 'foo', set: '<NULL>' kobject: 'foo' (ffffffffa00743d0): kobject_uevent_env kobject: 'foo' (ffffffffa00743d0): fill_kobj_path: path = '/module/foo' kobject: 'notes' (ffff88017fa9b668): kobject_add_internal: parent: 'foo', set: '<NULL>' ^^^^^ # rmmod foo kobject: 'holders' (ffff88017e7c5770): kobject_cleanup kobject: 'holders' (ffff88017e7c5770): auto cleanup kobject_del kobject: 'holders' (ffff88017e7c5770): calling ktype release kobject: (ffff88017e7c5770): dynamic_kobj_release kobject: 'holders': free name kobject: 'foo' (ffffffffa00743d0): kobject_cleanup kobject: 'foo' (ffffffffa00743d0): does not have a release() function, it is broken and must be fixed. kobject: 'foo' (ffffffffa00743d0): auto cleanup 'remove' event kobject: 'foo' (ffffffffa00743d0): kobject_uevent_env kobject: 'foo' (ffffffffa00743d0): fill_kobj_path: path = '/module/foo' kobject: 'foo' (ffffffffa00743d0): auto cleanup kobject_del kobject: 'foo': free name [whooops] Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-10-14ftrace: remove old pointers to mcountSteven Rostedt
When a mcount pointer is recorded into a table, it is used to add or remove calls to mcount (replacing them with nops). If the code is removed via removing a module, the pointers still exist. At modifying the code a check is always made to make sure the code being replaced is the code expected. In-other-words, the code being replaced is compared to what it is expected to be before being replaced. There is a very small chance that the code being replaced just happens to look like code that calls mcount (very small since the call to mcount is relative). To remove this chance, this patch adds ftrace_release to allow module unloading to remove the pointers to mcount within the module. Another change for init calls is made to not trace calls marked with __init. The tracing can not be started until after init is done anyway. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-14ftrace: enable mcount recording for modulesSteven Rostedt
This patch enables the loading of the __mcount_section of modules and changing all the callers of mcount into nops. The modification is done before the init_module function is called, so again, we do not need to use kstop_machine to make these changes. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-14tracing: Kernel TracepointsMathieu Desnoyers
Implementation of kernel tracepoints. Inspired from the Linux Kernel Markers. Allows complete typing verification by declaring both tracing statement inline functions and probe registration/unregistration static inline functions within the same macro "DEFINE_TRACE". No format string is required. See the tracepoint Documentation and Samples patches for usage examples. Taken from the documentation patch : "A tracepoint placed in code provides a hook to call a function (probe) that you can provide at runtime. A tracepoint can be "on" (a probe is connected to it) or "off" (no probe is attached). When a tracepoint is "off" it has no effect, except for adding a tiny time penalty (checking a condition for a branch) and space penalty (adding a few bytes for the function call at the end of the instrumented function and adds a data structure in a separate section). When a tracepoint is "on", the function you provide is called each time the tracepoint is executed, in the execution context of the caller. When the function provided ends its execution, it returns to the caller (continuing from the tracepoint site). You can put tracepoints at important locations in the code. They are lightweight hooks that can pass an arbitrary number of parameters, which prototypes are described in a tracepoint declaration placed in a header file." Addition and removal of tracepoints is synchronized by RCU using the scheduler (and preempt_disable) as guarantees to find a quiescent state (this is really RCU "classic"). The update side uses rcu_barrier_sched() with call_rcu_sched() and the read/execute side uses "preempt_disable()/preempt_enable()". We make sure the previous array containing probes, which has been scheduled for deletion by the rcu callback, is indeed freed before we proceed to the next update. It therefore limits the rate of modification of a single tracepoint to one update per RCU period. The objective here is to permit fast batch add/removal of probes on _different_ tracepoints. Changelog : - Use #name ":" #proto as string to identify the tracepoint in the tracepoint table. This will make sure not type mismatch happens due to connexion of a probe with the wrong type to a tracepoint declared with the same name in a different header. - Add tracepoint_entry_free_old. - Change __TO_TRACE to get rid of the 'i' iterator. Masami Hiramatsu <mhiramat@redhat.com> : Tested on x86-64. Performance impact of a tracepoint : same as markers, except that it adds about 70 bytes of instructions in an unlikely branch of each instrumented function (the for loop, the stack setup and the function call). It currently adds a memory read, a test and a conditional branch at the instrumentation site (in the hot path). Immediate values will eventually change this into a load immediate, test and branch, which removes the memory read which will make the i-cache impact smaller (changing the memory read for a load immediate removes 3-4 bytes per site on x86_32 (depending on mov prefixes), or 7-8 bytes on x86_64, it also saves the d-cache hit). About the performance impact of tracepoints (which is comparable to markers), even without immediate values optimizations, tests done by Hideo Aoki on ia64 show no regression. His test case was using hackbench on a kernel where scheduler instrumentation (about 5 events in code scheduler code) was added. Quoting Hideo Aoki about Markers : I evaluated overhead of kernel marker using linux-2.6-sched-fixes git tree, which includes several markers for LTTng, using an ia64 server. While the immediate trace mark feature isn't implemented on ia64, there is no major performance regression. So, I think that we don't have any issues to propose merging marker point patches into Linus's tree from the viewpoint of performance impact. I prepared two kernels to evaluate. The first one was compiled without CONFIG_MARKERS. The second one was enabled CONFIG_MARKERS. I downloaded the original hackbench from the following URL: http://devresources.linux-foundation.org/craiger/hackbench/src/hackbench.c I ran hackbench 5 times in each condition and calculated the average and difference between the kernels. The parameter of hackbench: every 50 from 50 to 800 The number of CPUs of the server: 2, 4, and 8 Below is the results. As you can see, major performance regression wasn't found in any case. Even if number of processes increases, differences between marker-enabled kernel and marker- disabled kernel doesn't increase. Moreover, if number of CPUs increases, the differences doesn't increase either. Curiously, marker-enabled kernel is better than marker-disabled kernel in more than half cases, although I guess it comes from the difference of memory access pattern. * 2 CPUs Number of | without | with | diff | diff | processes | Marker [Sec] | Marker [Sec] | [Sec] | [%] | -------------------------------------------------------------- 50 | 4.811 | 4.872 | +0.061 | +1.27 | 100 | 9.854 | 10.309 | +0.454 | +4.61 | 150 | 15.602 | 15.040 | -0.562 | -3.6 | 200 | 20.489 | 20.380 | -0.109 | -0.53 | 250 | 25.798 | 25.652 | -0.146 | -0.56 | 300 | 31.260 | 30.797 | -0.463 | -1.48 | 350 | 36.121 | 35.770 | -0.351 | -0.97 | 400 | 42.288 | 42.102 | -0.186 | -0.44 | 450 | 47.778 | 47.253 | -0.526 | -1.1 | 500 | 51.953 | 52.278 | +0.325 | +0.63 | 550 | 58.401 | 57.700 | -0.701 | -1.2 | 600 | 63.334 | 63.222 | -0.112 | -0.18 | 650 | 68.816 | 68.511 | -0.306 | -0.44 | 700 | 74.667 | 74.088 | -0.579 | -0.78 | 750 | 78.612 | 79.582 | +0.970 | +1.23 | 800 | 85.431 | 85.263 | -0.168 | -0.2 | -------------------------------------------------------------- * 4 CPUs Number of | without | with | diff | diff | processes | Marker [Sec] | Marker [Sec] | [Sec] | [%] | -------------------------------------------------------------- 50 | 2.586 | 2.584 | -0.003 | -0.1 | 100 | 5.254 | 5.283 | +0.030 | +0.56 | 150 | 8.012 | 8.074 | +0.061 | +0.76 | 200 | 11.172 | 11.000 | -0.172 | -1.54 | 250 | 13.917 | 14.036 | +0.119 | +0.86 | 300 | 16.905 | 16.543 | -0.362 | -2.14 | 350 | 19.901 | 20.036 | +0.135 | +0.68 | 400 | 22.908 | 23.094 | +0.186 | +0.81 | 450 | 26.273 | 26.101 | -0.172 | -0.66 | 500 | 29.554 | 29.092 | -0.461 | -1.56 | 550 | 32.377 | 32.274 | -0.103 | -0.32 | 600 | 35.855 | 35.322 | -0.533 | -1.49 | 650 | 39.192 | 38.388 | -0.804 | -2.05 | 700 | 41.744 | 41.719 | -0.025 | -0.06 | 750 | 45.016 | 44.496 | -0.520 | -1.16 | 800 | 48.212 | 47.603 | -0.609 | -1.26 | -------------------------------------------------------------- * 8 CPUs Number of | without | with | diff | diff | processes | Marker [Sec] | Marker [Sec] | [Sec] | [%] | -------------------------------------------------------------- 50 | 2.094 | 2.072 | -0.022 | -1.07 | 100 | 4.162 | 4.273 | +0.111 | +2.66 | 150 | 6.485 | 6.540 | +0.055 | +0.84 | 200 | 8.556 | 8.478 | -0.078 | -0.91 | 250 | 10.458 | 10.258 | -0.200 | -1.91 | 300 | 12.425 | 12.750 | +0.325 | +2.62 | 350 | 14.807 | 14.839 | +0.032 | +0.22 | 400 | 16.801 | 16.959 | +0.158 | +0.94 | 450 | 19.478 | 19.009 | -0.470 | -2.41 | 500 | 21.296 | 21.504 | +0.208 | +0.98 | 550 | 23.842 | 23.979 | +0.137 | +0.57 | 600 | 26.309 | 26.111 | -0.198 | -0.75 | 650 | 28.705 | 28.446 | -0.259 | -0.9 | 700 | 31.233 | 31.394 | +0.161 | +0.52 | 750 | 34.064 | 33.720 | -0.344 | -1.01 | 800 | 36.320 | 36.114 | -0.206 | -0.57 | -------------------------------------------------------------- Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Acked-by: Masami Hiramatsu <mhiramat@redhat.com> Acked-by: 'Peter Zijlstra' <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-10Staging: add TAINT_CRAP for all drivers/staging codeGreg Kroah-Hartman
We need to add a flag for all code that is in the drivers/staging/ directory to prevent all other kernel developers from worrying about issues here, and to notify users that the drivers might not be as good as they are normally used to. Based on code from Andreas Gruenbacher and Jeff Mahoney to provide a TAINT flag for the support level of a kernel module in the Novell enterprise kernel release. This is the kernel portion of this feature, the ability for the flag to be set needs to be done in the build process and will happen in a follow-up patch. Cc: Andreas Gruenbacher <agruen@suse.de> Cc: Jeff Mahoney <jeffm@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-08-25[module] Don't let gcc inline load_module()Linus Torvalds
'load_module()' is a complex function that contains all the ELF section logic, and inlining it is utterly insane. But gcc will do it, simply because there is only one call-site. As a result, all the stack space that is allocated for all the work to load the module will still be active when we actually call the module init sequence, and the deep call chain makes stack overflows happen. And stack overflows are really hard to debug, because they not only corrupt random pages below the stack, but also corrupt the thread_info structure that is allocated under the stack. In this case, Alan Brunelle reported some crazy oopses at bootup, after loading the processor module that ends up doing complex ACPI stuff and has quite a deep callchain. This should fix it, and is the sane thing to do regardless. Cc: Alan D. Brunelle <Alan.Brunelle@hp.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-12modules: extend initcall_debug functionality to the module loaderArjan van de Ven
The kernel has this really nice facility where if you put "initcall_debug" on the kernel commandline, it'll print which function it's going to execute just before calling an initcall, and then after the call completes it will 1) print if it had an error code 2) checks for a few simple bugs (like leaving irqs off) and 3) print how long the init call took in milliseconds. While trying to optimize the boot speed of my laptop, I have been loving number 3 to figure out what to optimize... ... and then I wished that the same thing was done for module loading. This patch makes the module loader use this exact same functionality; it's a logical extension in my view (since modules are just sort of late binding initcalls anyway) and so far I've found it quite useful in finding where things are too slow in my boot. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-07-28stop_machine: Wean existing callers off stop_machine_run()Rusty Russell
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-07-28module: fix build warning with !CONFIG_KALLSYMSWANG Cong
This patch fixed the warning: CC kernel/module.o /home/wangcong/Projects/linux-2.6/kernel/module.c:332: warning: ‘lookup_symbol’ defined but not used Signed-off-by: WANG Cong <wangcong@zeuux.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-07-22modules: Take a shortcut for checking if an address is in a moduleRusty Russell
This patch keeps track of the boundaries of module allocation, in order to speed up module_text_address(). Inspired by Arjan's version, which required arch-specific defines: Various pieces of the kernel (lockdep, latencytop, etc) tend to store backtraces, sometimes at a relatively high frequency. In itself this isn't a big performance deal (after all you're using diagnostics features), but there have been some complaints from people who have over 100 modules loaded that this is a tad too slow. This is due to the new backtracer code which looks at every slot on the stack to see if it's a kernel/module text address, so that's 1024 slots. 1024 times 100 modules... that's a lot of list walking. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-07-22module: turn longs into ints for module sizesDenys Vlasenko
This shrinks module.o and each *.ko file. And finally, structure members which hold length of module code (four such members there) and count of symbols are converted from longs to ints. We cannot possibly have a module where 32 bits won't be enough to hold such counts. For one, module loading checks module size for sanity before loading, so such insanely big module will fail that test first. Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-07-22Shrink struct module: CONFIG_UNUSED_SYMBOLS ifdefsDenys Vlasenko
module.c and module.h conatains code for finding exported symbols which are declared with EXPORT_UNUSED_SYMBOL, and this code is compiled in even if CONFIG_UNUSED_SYMBOLS is not set and thus there can be no EXPORT_UNUSED_SYMBOLs in modules anyway (because EXPORT_UNUSED_SYMBOL(x) are compiled out to nothing then). This patch adds required #ifdefs. Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-07-22module: generic each_symbol iterator functionRusty Russell
Introduce an each_symbol() iterator to avoid duplicating the knowledge about the 5 different sections containing symbols. Currently only used by find_symbol(), but will be used by symbol_put_addr() too. (Includes NULL ptr deref fix by Jiri Kosina <jkosina@suse.cz>) Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Jiri Kosina <jkosina@suse.cz>
2008-07-22module: don't use stop_machine for waiting rmmodRusty Russell
rmmod has a little-used "-w" option, meaning that instead of failing if the module is in use, it should block until the module becomes unused. In this case, we don't need to use stop_machine: Max Krasnyansky indicated that would be useful for SystemTap which loads/unloads new modules frequently. Cc: Max Krasnyansky <maxk@qualcomm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-05-23modules: proper cleanup of kobject without CONFIG_SYSFSDenis V. Lunev
kobject: '<NULL>' (ffffffffa0104050): is not initialized, yet kobject_put() is being called. ------------[ cut here ]------------ WARNING: at /home/den/src/linux-netns26/lib/kobject.c:583 kobject_put+0x53/0x55() Modules linked in: ipv6 nfsd lockd nfs_acl auth_rpcgss sunrpc exportfs ide_cd_mod cdrom button [last unloaded: pktgen] comm: rmmod Tainted: G W 2.6.26-rc3 #585 Call Trace: [<ffffffff802359ab>] warn_on_slowpath+0x58/0x7a [<ffffffff80236aca>] ? printk+0x67/0x69 [<ffffffff80236aca>] ? printk+0x67/0x69 [<ffffffff80324289>] kobject_put+0x53/0x55 [<ffffffff8025e2ee>] free_module+0x87/0xfa [<ffffffff8025fee5>] sys_delete_module+0x178/0x1e1 [<ffffffff804b1e70>] ? lockdep_sys_exit_thunk+0x35/0x67 [<ffffffff804b1dff>] ? trace_hardirqs_on_thunk+0x35/0x3a [<ffffffff8020c0bb>] system_call_after_swapgs+0x7b/0x80 ---[ end trace 8f5aafa7f6406cf8 ]--- mod->mkobj.kobj is not initialized without CONFIG_SYSFS. Do not call kobject_put in this case. Signed-off-by: Denis V. Lunev <den@openvz.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-05-23module loading ELF handling: use SELFMAG instead of numeric constantCyrill Gorcunov
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-05-09module: don't ignore vermagic string if module doesn't have modversionsRusty Russell
Linus found a logic bug: we ignore the version number in a module's vermagic string if we have CONFIG_MODVERSIONS set, but modversions also lets through a module with no __versions section for modprobe --force (with tainting, but still). We should only ignore the start of the vermagic string if the module actually *has* crcs to check. Rather than (say) having an entertaining hissy fit and creating a config option to work around the buggy code. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-09module: be more picky about allowing missing module versionsRusty Russell
We allow missing __versions sections, because modprobe --force strips it. It makes less sense to allow sections where there's no version for a specific symbol the module uses, so disallow that. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-04Make forced module loading optionalLinus Torvalds
The kernel module loader used to be much too happy to allow loading of modules for the wrong kernel version by default. For example, if you had MODVERSIONS enabled, but tried to load a module with no version info, it would happily load it and taint the kernel - whether it was likely to actually work or not! Generally, such forced module loading should be considered a really really bad idea, so make it conditional on a new config option (MODULE_FORCE_LOAD), and make it default to off. If somebody really wants to force module loads, that's their problem, but we should not encourage it. Especially as it happened to me by mistake (ie regular unversioned Fedora modules getting loaded) causing lots of strange behavior. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-01module: add MODULE_STATE_GOING notifier callPeter Oberparleiter
Provide module unload callback. Required by the gcov profiling infrastructure to keep track of profiling data structures. Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-05-01module: Enhance verify_export_symbolsRusty Russell
Make verify_export_symbols check the modules unused, unused_gpl and gpl_future syms. Inspired by Jan Beulich's fix, but table-driven. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-05-01module: set unused_gpl_crcs instead of overwriting unused_crcsRusty Russell
Obvious typo, but I don't know of any modules with unused GPL exports, and then it would take someone noticing that the version shouldn't have matched in a dependent module. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-05-01module: neaten __find_symbol, rename to find_symbolRusty Russell
__find_symbol() has grown over time: there are now 5 different arrays of symbols it traverses. It also shouldn't print out a warning on some calls (ie. verify_symbol which simply checks for name clashes, and __symbol_put which checks for bugs). 1) Rename to find_symbol: no need for underscores. 2) Use bool and add "warn" parameter to suppress warnings. 3) Make table-driven rather than open coded. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-05-01module: reduce module image and resident sizeRusty Russell
Resulting reduction (x86-64, gcc 4.1.2) with my (special purpose, i.e. much reduced) configurations: - 16k kernel resident size - 180k module resident size - 10k module image size Signed-off-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-05-01module: make module_sect_attrs private to kernel/module.cRusty Russell
No-one else is using these afaics. Signed-off-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-04-18kernel: Remove unnecessary inclusions of asm/semaphore.hMatthew Wilcox
None of these files use any of the functionality promised by asm/semaphore.h. Signed-off-by: Matthew Wilcox <willy@linux.intel.com>