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2010-05-14tracing: Let tracepoints have data passed to tracepoint callbacksSteven Rostedt
This patch adds data to be passed to tracepoint callbacks. The created functions from DECLARE_TRACE() now need a mandatory data parameter. For example: DECLARE_TRACE(mytracepoint, int value, value) Will create the register function: int register_trace_mytracepoint((void(*)(void *data, int value))probe, void *data); As the first argument, all callbacks (probes) must take a (void *data) parameter. So a callback for the above tracepoint will look like: void myprobe(void *data, int value) { } The callback may choose to ignore the data parameter. This change allows callbacks to register a private data pointer along with the function probe. void mycallback(void *data, int value); register_trace_mytracepoint(mycallback, mydata); Then the mycallback() will receive the "mydata" as the first parameter before the args. A more detailed example: DECLARE_TRACE(mytracepoint, TP_PROTO(int status), TP_ARGS(status)); /* In the C file */ DEFINE_TRACE(mytracepoint, TP_PROTO(int status), TP_ARGS(status)); [...] trace_mytracepoint(status); /* In a file registering this tracepoint */ int my_callback(void *data, int status) { struct my_struct my_data = data; [...] } [...] my_data = kmalloc(sizeof(*my_data), GFP_KERNEL); init_my_data(my_data); register_trace_mytracepoint(my_callback, my_data); The same callback can also be registered to the same tracepoint as long as the data registered is different. Note, the data must also be used to unregister the callback: unregister_trace_mytracepoint(my_callback, my_data); Because of the data parameter, tracepoints declared this way can not have no args. That is: DECLARE_TRACE(mytracepoint, TP_PROTO(void), TP_ARGS()); will cause an error. If no arguments are needed, a new macro can be used instead: DECLARE_TRACE_NOARGS(mytracepoint); Since there are no arguments, the proto and args fields are left out. This is part of a series to make the tracepoint footprint smaller: text data bss dec hex filename 4913961 1088356 861512 6863829 68bbd5 vmlinux.orig 4914025 1088868 861512 6864405 68be15 vmlinux.class 4918492 1084612 861512 6864616 68bee8 vmlinux.tracepoint Again, this patch also increases the size of the kernel, but lays the ground work for decreasing it. v5: Fixed net/core/drop_monitor.c to handle these updates. v4: Moved the DECLARE_TRACE() DECLARE_TRACE_NOARGS out of the #ifdef CONFIG_TRACE_POINTS, since the two are the same in both cases. The __DECLARE_TRACE() is what changes. Thanks to Frederic Weisbecker for pointing this out. v3: Made all register_* functions require data to be passed and all callbacks to take a void * parameter as its first argument. This makes the calling functions comply with C standards. Also added more comments to the modifications of DECLARE_TRACE(). v2: Made the DECLARE_TRACE() have the ability to pass arguments and added a new DECLARE_TRACE_NOARGS() for tracepoints that do not need any arguments. Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Acked-by: Masami Hiramatsu <mhiramat@redhat.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: David S. Miller <davem@davemloft.net> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2009-07-10tracing/workqueues: Add refcnt to struct cpu_workqueue_statsLai Jiangshan
The stat entries can be freed when the stat file is being read. The worse is, the ptr can be freed immediately after it's returned from workqueue_stat_start/next(). Add a refcnt to struct cpu_workqueue_stats to avoid use-after-free. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <4A51B16F.6010608@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-02trace_workqueue: remove blank line between each cpuZhaolei
The blankline between each cpu's workqueue stat is not necessary, because the cpu number is enough to part them by eye. Old style also caused a blankline below headline, and made code complex by using lock, disableirq and get cpu var. Old style: # CPU INSERTED EXECUTED NAME # | | | | 0 8644 8644 events/0 0 0 0 cpuset ... 0 1 1 kdmflush 1 35365 35365 events/1 ... New style: # CPU INSERTED EXECUTED NAME # | | | | 0 8644 8644 events/0 0 0 0 cpuset ... 0 1 1 kdmflush 1 35365 35365 events/1 ... [ Impact: provide more readable code ] Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tom Zanussi <tzanussi@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-06-02trace_workqueue: remove cpu_workqueue_stats->first_entryZhaolei
cpu_workqueue_stats->first_entry is useless because we can retrieve the header of a cpu workqueue using: if (&cpu_workqueue_stats->list == workqueue_cpu_stat(cpu)->list.next) [ Impact: cleanup ] Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tom Zanussi <tzanussi@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-06-02trace_workqueue: use list_for_each_entry() instead of list_for_each_entry_safe()Zhaolei
No need to use list_for_each_entry_safe() in iteration without deleting any node, we can use list_for_each_entry() instead. [ Impact: cleanup ] Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tom Zanussi <tzanussi@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-06-02ftrace, workqueuetrace: make workqueue tracepoints use TRACE_EVENT macroZhaolei
v3: zhaolei@cn.fujitsu.com: Change TRACE_EVENT definition to new format introduced by Steven Rostedt: consolidate trace and trace_event headers v2: kosaki@jp.fujitsu.com: print the function names instead of addr, and zap the work addr v1: zhaolei@cn.fujitsu.com: Make workqueue tracepoints use TRACE_EVENT macro TRACE_EVENT is a more generic way to define tracepoints. Doing so adds these new capabilities to the tracepoints: - zero-copy and per-cpu splice() tracing - binary tracing without printf overhead - structured logging records exposed under /debug/tracing/events - trace events embedded in function tracer output and other plugins - user-defined, per tracepoint filter expressions Then, this patch converts DEFINE_TRACE to TRACE_EVENT in workqueue related tracepoints. [ Impact: expand workqueue tracer to events tracing ] Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tom Zanussi <tzanussi@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-04-07Merge branch 'linus' into tracing/coreIngo Molnar
Merge reason: update to upstream tracing facilities Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-25trace_workqueues: fix empty line's outputLai Jiangshan
Empty lines separate cpus stat. After previous fix(trace_stat: keep original order) applied, the empty lines are displayed at incorrect position. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Acked-by: Steven Rostedt <srostedt@redhat.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <49C9F266.2060706@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-24tracing: add handler to trace_statSteven Rostedt
Currently, if a trace_stat user wants a handle to some private data, the trace_stat infrastructure does not supply a way to do that. This patch passes the trace_stat structure to the start function of the trace_stat code. Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-03-12tracing: Don't use tracing_record_cmdline() in workqueue tracer fixKOSAKI Motohiro
commit c3ffc7a40b7e94b094efe1c8ab4e24370a782b65 "Don't use tracing_record_cmdline() in workqueue tracer" has a race window. find_task_by_vpid() requires task_list_lock(). LKML-Reference: <20090313090042.43CD.A69D9226@jp.fujitsu.com> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-03-10Merge branch 'tip/tracing/ftrace' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/ftrace
2009-03-10tracing: remove funky whitespace in the trace codeSteven Rostedt
Impact: clean up There existed a lot of <space><tab>'s in the tracing code. This patch removes them. Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-03-10tracing: Don't assume possible cpu list have continuous numbersKOSAKI Motohiro
"for (++cpu ; cpu < num_possible_cpus(); cpu++)" statement assumes possible cpus have continuous number - but that's a wrong assumption. Insted, cpumask_next() should be used. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Steven Rostedt <srostedt@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <20090310104437.A480.A69D9226@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-09tracing: Don't use tracing_record_cmdline() in workqueue tracerKOSAKI Motohiro
Impact: improve workqueue tracer output Currently, /sys/kernel/debug/tracing/trace_stat/workqueues can display wrong and strange thread names. Why? Currently, ftrace has tracing_record_cmdline()/trace_find_cmdline() convenience function that implements a task->comm string cache. This can avoid unnecessary memcpy overhead and the workqueue tracer uses it. However, in general, any trace statistics feature shouldn't use tracing_record_cmdline() because trace statistics can display very old process. Then comm cache can return wrong string because recent process overrides the cache. Fortunately, workqueue trace guarantees that displayed processes are live. Thus we can search comm string from PID at display time. <before> % cat workqueues # CPU INSERTED EXECUTED NAME # | | | | 7 431913 431913 kondemand/7 7 0 0 tail 7 21 21 git 7 0 0 ls 7 9 9 cat 7 832632 832632 unix_chkpwd 7 236292 236292 ls Note: tail, git, ls, cat unix_chkpwd are obiously not workqueue thread. <after> % cat workqueues # CPU INSERTED EXECUTED NAME # | | | | 7 510 510 kondemand/7 7 0 0 kmpathd/7 7 15 15 ata/7 7 0 0 aio/7 7 11 11 kblockd/7 7 1063 1063 work_on_cpu/7 7 167 167 events/7 Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Steven Rostedt <srostedt@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-20trace_workqueue: use percpu data for workqueue statLai Jiangshan
Impact: use percpu data instead of a global structure Use: static DEFINE_PER_CPU(struct workqueue_global_stats, all_workqueue_stat); instead of allocating a global structure. percpu data also works well on NUMA. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-14tracing: add a new workqueue tracerFrederic Weisbecker
Impact: new tracer The workqueue tracer provides some statistical informations about each cpu workqueue thread such as the number of the works inserted and executed since their creation. It can help to evaluate the amount of work each of them have to perform. For example it can help a developer to decide whether he should choose a per cpu workqueue instead of a singlethreaded one. It only traces statistical informations for now but it will probably later provide event tracing too. Such a tracer could help too, and be improved, to help rt priority sorted workqueue development. To have a snapshot of the workqueues state at any time, just do cat /debugfs/tracing/trace_stat/workqueues Ie: 1 125 125 reiserfs/1 1 0 0 scsi_tgtd/1 1 0 0 aio/1 1 0 0 ata/1 1 114 114 kblockd/1 1 0 0 kintegrityd/1 1 2147 2147 events/1 0 0 0 kpsmoused 0 105 105 reiserfs/0 0 0 0 scsi_tgtd/0 0 0 0 aio/0 0 0 0 ata_aux 0 0 0 ata/0 0 0 0 cqueue 0 0 0 kacpi_notify 0 0 0 kacpid 0 149 149 kblockd/0 0 0 0 kintegrityd/0 0 1000 1000 khelper 0 2270 2270 events/0 Changes in V2: _ Drop the static array based on NR_CPU and dynamically allocate the stat array with num_possible_cpus() and other cpu mask facilities.... _ Trace workqueue insertion at a bit lower level (insert_work instead of queue_work) to handle even the workqueue barriers. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>