From 633f6f58af445022e38417599a4789b5fc510b71 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Fri, 19 Feb 2016 13:59:54 -0500 Subject: tracing: Remove duplicate checks for online CPUs Some trace events have conditions that check if the current CPU is online or not before recording the tracepoint. That's because certain trace events are in locations that can be called as the CPU is going offline and when RCU no longer monitors it (like kfree and friends). The check was added because trace events require RCU to be active. This is a trace event infrastructure issue and not something that individual trace events should worry about. The tracepoint.h code now has added a check to see if the current CPU is considered online, and it only does the tracepoint if it is. There's no more need for individual trace events to also include this check. It is now redundant. Cc: Shreyas B. Prabhu Signed-off-by: Steven Rostedt --- include/trace/events/kmem.h | 42 ++++-------------------------------------- include/trace/events/tlb.h | 4 +--- 2 files changed, 5 insertions(+), 41 deletions(-) (limited to 'include/trace') diff --git a/include/trace/events/kmem.h b/include/trace/events/kmem.h index f7554fd7fc62..325b2a9b1959 100644 --- a/include/trace/events/kmem.h +++ b/include/trace/events/kmem.h @@ -140,42 +140,19 @@ DEFINE_EVENT(kmem_free, kfree, TP_ARGS(call_site, ptr) ); -DEFINE_EVENT_CONDITION(kmem_free, kmem_cache_free, +DEFINE_EVENT(kmem_free, kmem_cache_free, TP_PROTO(unsigned long call_site, const void *ptr), - TP_ARGS(call_site, ptr), - - /* - * This trace can be potentially called from an offlined cpu. - * Since trace points use RCU and RCU should not be used from - * offline cpus, filter such calls out. - * While this trace can be called from a preemptable section, - * it has no impact on the condition since tasks can migrate - * only from online cpus to other online cpus. Thus its safe - * to use raw_smp_processor_id. - */ - TP_CONDITION(cpu_online(raw_smp_processor_id())) + TP_ARGS(call_site, ptr) ); -TRACE_EVENT_CONDITION(mm_page_free, +TRACE_EVENT(mm_page_free, TP_PROTO(struct page *page, unsigned int order), TP_ARGS(page, order), - - /* - * This trace can be potentially called from an offlined cpu. - * Since trace points use RCU and RCU should not be used from - * offline cpus, filter such calls out. - * While this trace can be called from a preemptable section, - * it has no impact on the condition since tasks can migrate - * only from online cpus to other online cpus. Thus its safe - * to use raw_smp_processor_id. - */ - TP_CONDITION(cpu_online(raw_smp_processor_id())), - TP_STRUCT__entry( __field( unsigned long, pfn ) __field( unsigned int, order ) @@ -276,23 +253,12 @@ DEFINE_EVENT(mm_page, mm_page_alloc_zone_locked, TP_ARGS(page, order, migratetype) ); -TRACE_EVENT_CONDITION(mm_page_pcpu_drain, +TRACE_EVENT(mm_page_pcpu_drain, TP_PROTO(struct page *page, unsigned int order, int migratetype), TP_ARGS(page, order, migratetype), - /* - * This trace can be potentially called from an offlined cpu. - * Since trace points use RCU and RCU should not be used from - * offline cpus, filter such calls out. - * While this trace can be called from a preemptable section, - * it has no impact on the condition since tasks can migrate - * only from online cpus to other online cpus. Thus its safe - * to use raw_smp_processor_id. - */ - TP_CONDITION(cpu_online(raw_smp_processor_id())), - TP_STRUCT__entry( __field( unsigned long, pfn ) __field( unsigned int, order ) diff --git a/include/trace/events/tlb.h b/include/trace/events/tlb.h index bc8815f45f3b..9d14b1992108 100644 --- a/include/trace/events/tlb.h +++ b/include/trace/events/tlb.h @@ -34,13 +34,11 @@ TLB_FLUSH_REASON #define EM(a,b) { a, b }, #define EMe(a,b) { a, b } -TRACE_EVENT_CONDITION(tlb_flush, +TRACE_EVENT(tlb_flush, TP_PROTO(int reason, unsigned long pages), TP_ARGS(reason, pages), - TP_CONDITION(cpu_online(smp_processor_id())), - TP_STRUCT__entry( __field( int, reason) __field(unsigned long, pages) -- cgit v1.2.3 From a664edb374c704a734a0df41fc742c285a5beb52 Mon Sep 17 00:00:00 2001 From: Yang Shi Date: Thu, 3 Mar 2016 01:08:57 -0800 Subject: tracing, writeback: Replace cgroup path to cgroup ino commit 5634cc2aa9aebc77bc862992e7805469dcf83dac ("writeback: update writeback tracepoints to report cgroup") made writeback tracepoints print out cgroup path when CGROUP_WRITEBACK is enabled, but it may trigger the below bug on -rt kernel since kernfs_path and kernfs_path_len are called by tracepoints, which acquire spin lock that is sleepable on -rt kernel. BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:930 in_atomic(): 1, irqs_disabled(): 0, pid: 625, name: kworker/u16:3 INFO: lockdep is turned off. Preemption disabled at:[] wb_writeback+0xec/0x830 CPU: 7 PID: 625 Comm: kworker/u16:3 Not tainted 4.4.1-rt5 #20 Hardware name: Freescale Layerscape 2085a RDB Board (DT) Workqueue: writeback wb_workfn (flush-7:0) Call trace: [] dump_backtrace+0x0/0x200 [] show_stack+0x24/0x30 [] dump_stack+0x88/0xa8 [] ___might_sleep+0x2ec/0x300 [] rt_spin_lock+0x38/0xb8 [] kernfs_path_len+0x30/0x90 [] trace_event_raw_event_writeback_work_class+0xe8/0x2e8 [] wb_writeback+0x620/0x830 [] wb_workfn+0x61c/0x950 [] process_one_work+0x3ac/0xb30 [] worker_thread+0x9c/0x7a8 [] kthread+0x190/0x1b0 [] ret_from_fork+0x10/0x30 With unlocked kernfs_* functions, synchronize_sched() has to be called in kernfs_rename which could be called in syscall path, but it is problematic. So, print out cgroup ino instead of path name, which could be converted to path name by userland. Withouth CGROUP_WRITEBACK enabled, it just prints out root dir. But, root dir ino vary from different filesystems, so printing out -1U to indicate an invalid cgroup ino. Link: http://lkml.kernel.org/r/1456996137-8354-1-git-send-email-yang.shi@linaro.org Acked-by: Tejun Heo Signed-off-by: Yang Shi Signed-off-by: Steven Rostedt --- include/trace/events/writeback.h | 121 +++++++++++++++------------------------ 1 file changed, 45 insertions(+), 76 deletions(-) (limited to 'include/trace') diff --git a/include/trace/events/writeback.h b/include/trace/events/writeback.h index fff846b512e6..73614ce1d204 100644 --- a/include/trace/events/writeback.h +++ b/include/trace/events/writeback.h @@ -134,58 +134,28 @@ DEFINE_EVENT(writeback_dirty_inode_template, writeback_dirty_inode, #ifdef CREATE_TRACE_POINTS #ifdef CONFIG_CGROUP_WRITEBACK -static inline size_t __trace_wb_cgroup_size(struct bdi_writeback *wb) +static inline unsigned int __trace_wb_assign_cgroup(struct bdi_writeback *wb) { - return kernfs_path_len(wb->memcg_css->cgroup->kn) + 1; + return wb->memcg_css->cgroup->kn->ino; } -static inline void __trace_wb_assign_cgroup(char *buf, struct bdi_writeback *wb) -{ - struct cgroup *cgrp = wb->memcg_css->cgroup; - char *path; - - path = cgroup_path(cgrp, buf, kernfs_path_len(cgrp->kn) + 1); - WARN_ON_ONCE(path != buf); -} - -static inline size_t __trace_wbc_cgroup_size(struct writeback_control *wbc) -{ - if (wbc->wb) - return __trace_wb_cgroup_size(wbc->wb); - else - return 2; -} - -static inline void __trace_wbc_assign_cgroup(char *buf, - struct writeback_control *wbc) +static inline unsigned int __trace_wbc_assign_cgroup(struct writeback_control *wbc) { if (wbc->wb) - __trace_wb_assign_cgroup(buf, wbc->wb); + return __trace_wb_assign_cgroup(wbc->wb); else - strcpy(buf, "/"); + return -1U; } - #else /* CONFIG_CGROUP_WRITEBACK */ -static inline size_t __trace_wb_cgroup_size(struct bdi_writeback *wb) -{ - return 2; -} - -static inline void __trace_wb_assign_cgroup(char *buf, struct bdi_writeback *wb) -{ - strcpy(buf, "/"); -} - -static inline size_t __trace_wbc_cgroup_size(struct writeback_control *wbc) +static inline unsigned int __trace_wb_assign_cgroup(struct bdi_writeback *wb) { - return 2; + return -1U; } -static inline void __trace_wbc_assign_cgroup(char *buf, - struct writeback_control *wbc) +static inline unsigned int __trace_wbc_assign_cgroup(struct writeback_control *wbc) { - strcpy(buf, "/"); + return -1U; } #endif /* CONFIG_CGROUP_WRITEBACK */ @@ -201,7 +171,7 @@ DECLARE_EVENT_CLASS(writeback_write_inode_template, __array(char, name, 32) __field(unsigned long, ino) __field(int, sync_mode) - __dynamic_array(char, cgroup, __trace_wbc_cgroup_size(wbc)) + __field(unsigned int, cgroup_ino) ), TP_fast_assign( @@ -209,14 +179,14 @@ DECLARE_EVENT_CLASS(writeback_write_inode_template, dev_name(inode_to_bdi(inode)->dev), 32); __entry->ino = inode->i_ino; __entry->sync_mode = wbc->sync_mode; - __trace_wbc_assign_cgroup(__get_str(cgroup), wbc); + __entry->cgroup_ino = __trace_wbc_assign_cgroup(wbc); ), - TP_printk("bdi %s: ino=%lu sync_mode=%d cgroup=%s", + TP_printk("bdi %s: ino=%lu sync_mode=%d cgroup_ino=%u", __entry->name, __entry->ino, __entry->sync_mode, - __get_str(cgroup) + __entry->cgroup_ino ) ); @@ -246,7 +216,7 @@ DECLARE_EVENT_CLASS(writeback_work_class, __field(int, range_cyclic) __field(int, for_background) __field(int, reason) - __dynamic_array(char, cgroup, __trace_wb_cgroup_size(wb)) + __field(unsigned int, cgroup_ino) ), TP_fast_assign( strncpy(__entry->name, @@ -258,10 +228,10 @@ DECLARE_EVENT_CLASS(writeback_work_class, __entry->range_cyclic = work->range_cyclic; __entry->for_background = work->for_background; __entry->reason = work->reason; - __trace_wb_assign_cgroup(__get_str(cgroup), wb); + __entry->cgroup_ino = __trace_wb_assign_cgroup(wb); ), TP_printk("bdi %s: sb_dev %d:%d nr_pages=%ld sync_mode=%d " - "kupdate=%d range_cyclic=%d background=%d reason=%s cgroup=%s", + "kupdate=%d range_cyclic=%d background=%d reason=%s cgroup_ino=%u", __entry->name, MAJOR(__entry->sb_dev), MINOR(__entry->sb_dev), __entry->nr_pages, @@ -270,7 +240,7 @@ DECLARE_EVENT_CLASS(writeback_work_class, __entry->range_cyclic, __entry->for_background, __print_symbolic(__entry->reason, WB_WORK_REASON), - __get_str(cgroup) + __entry->cgroup_ino ) ); #define DEFINE_WRITEBACK_WORK_EVENT(name) \ @@ -300,15 +270,15 @@ DECLARE_EVENT_CLASS(writeback_class, TP_ARGS(wb), TP_STRUCT__entry( __array(char, name, 32) - __dynamic_array(char, cgroup, __trace_wb_cgroup_size(wb)) + __field(unsigned int, cgroup_ino) ), TP_fast_assign( strncpy(__entry->name, dev_name(wb->bdi->dev), 32); - __trace_wb_assign_cgroup(__get_str(cgroup), wb); + __entry->cgroup_ino = __trace_wb_assign_cgroup(wb); ), - TP_printk("bdi %s: cgroup=%s", + TP_printk("bdi %s: cgroup_ino=%u", __entry->name, - __get_str(cgroup) + __entry->cgroup_ino ) ); #define DEFINE_WRITEBACK_EVENT(name) \ @@ -347,7 +317,7 @@ DECLARE_EVENT_CLASS(wbc_class, __field(int, range_cyclic) __field(long, range_start) __field(long, range_end) - __dynamic_array(char, cgroup, __trace_wbc_cgroup_size(wbc)) + __field(unsigned int, cgroup_ino) ), TP_fast_assign( @@ -361,12 +331,12 @@ DECLARE_EVENT_CLASS(wbc_class, __entry->range_cyclic = wbc->range_cyclic; __entry->range_start = (long)wbc->range_start; __entry->range_end = (long)wbc->range_end; - __trace_wbc_assign_cgroup(__get_str(cgroup), wbc); + __entry->cgroup_ino = __trace_wbc_assign_cgroup(wbc); ), TP_printk("bdi %s: towrt=%ld skip=%ld mode=%d kupd=%d " "bgrd=%d reclm=%d cyclic=%d " - "start=0x%lx end=0x%lx cgroup=%s", + "start=0x%lx end=0x%lx cgroup_ino=%u", __entry->name, __entry->nr_to_write, __entry->pages_skipped, @@ -377,7 +347,7 @@ DECLARE_EVENT_CLASS(wbc_class, __entry->range_cyclic, __entry->range_start, __entry->range_end, - __get_str(cgroup) + __entry->cgroup_ino ) ) @@ -398,7 +368,7 @@ TRACE_EVENT(writeback_queue_io, __field(long, age) __field(int, moved) __field(int, reason) - __dynamic_array(char, cgroup, __trace_wb_cgroup_size(wb)) + __field(unsigned int, cgroup_ino) ), TP_fast_assign( unsigned long *older_than_this = work->older_than_this; @@ -408,15 +378,15 @@ TRACE_EVENT(writeback_queue_io, (jiffies - *older_than_this) * 1000 / HZ : -1; __entry->moved = moved; __entry->reason = work->reason; - __trace_wb_assign_cgroup(__get_str(cgroup), wb); + __entry->cgroup_ino = __trace_wb_assign_cgroup(wb); ), - TP_printk("bdi %s: older=%lu age=%ld enqueue=%d reason=%s cgroup=%s", + TP_printk("bdi %s: older=%lu age=%ld enqueue=%d reason=%s cgroup_ino=%u", __entry->name, __entry->older, /* older_than_this in jiffies */ __entry->age, /* older_than_this in relative milliseconds */ __entry->moved, __print_symbolic(__entry->reason, WB_WORK_REASON), - __get_str(cgroup) + __entry->cgroup_ino ) ); @@ -484,7 +454,7 @@ TRACE_EVENT(bdi_dirty_ratelimit, __field(unsigned long, dirty_ratelimit) __field(unsigned long, task_ratelimit) __field(unsigned long, balanced_dirty_ratelimit) - __dynamic_array(char, cgroup, __trace_wb_cgroup_size(wb)) + __field(unsigned int, cgroup_ino) ), TP_fast_assign( @@ -496,13 +466,13 @@ TRACE_EVENT(bdi_dirty_ratelimit, __entry->task_ratelimit = KBps(task_ratelimit); __entry->balanced_dirty_ratelimit = KBps(wb->balanced_dirty_ratelimit); - __trace_wb_assign_cgroup(__get_str(cgroup), wb); + __entry->cgroup_ino = __trace_wb_assign_cgroup(wb); ), TP_printk("bdi %s: " "write_bw=%lu awrite_bw=%lu dirty_rate=%lu " "dirty_ratelimit=%lu task_ratelimit=%lu " - "balanced_dirty_ratelimit=%lu cgroup=%s", + "balanced_dirty_ratelimit=%lu cgroup_ino=%u", __entry->bdi, __entry->write_bw, /* write bandwidth */ __entry->avg_write_bw, /* avg write bandwidth */ @@ -510,7 +480,7 @@ TRACE_EVENT(bdi_dirty_ratelimit, __entry->dirty_ratelimit, /* base ratelimit */ __entry->task_ratelimit, /* ratelimit with position control */ __entry->balanced_dirty_ratelimit, /* the balanced ratelimit */ - __get_str(cgroup) + __entry->cgroup_ino ) ); @@ -548,7 +518,7 @@ TRACE_EVENT(balance_dirty_pages, __field( long, pause) __field(unsigned long, period) __field( long, think) - __dynamic_array(char, cgroup, __trace_wb_cgroup_size(wb)) + __field(unsigned int, cgroup_ino) ), TP_fast_assign( @@ -571,7 +541,7 @@ TRACE_EVENT(balance_dirty_pages, __entry->period = period * 1000 / HZ; __entry->pause = pause * 1000 / HZ; __entry->paused = (jiffies - start_time) * 1000 / HZ; - __trace_wb_assign_cgroup(__get_str(cgroup), wb); + __entry->cgroup_ino = __trace_wb_assign_cgroup(wb); ), @@ -580,7 +550,7 @@ TRACE_EVENT(balance_dirty_pages, "bdi_setpoint=%lu bdi_dirty=%lu " "dirty_ratelimit=%lu task_ratelimit=%lu " "dirtied=%u dirtied_pause=%u " - "paused=%lu pause=%ld period=%lu think=%ld cgroup=%s", + "paused=%lu pause=%ld period=%lu think=%ld cgroup_ino=%u", __entry->bdi, __entry->limit, __entry->setpoint, @@ -595,7 +565,7 @@ TRACE_EVENT(balance_dirty_pages, __entry->pause, /* ms */ __entry->period, /* ms */ __entry->think, /* ms */ - __get_str(cgroup) + __entry->cgroup_ino ) ); @@ -609,8 +579,7 @@ TRACE_EVENT(writeback_sb_inodes_requeue, __field(unsigned long, ino) __field(unsigned long, state) __field(unsigned long, dirtied_when) - __dynamic_array(char, cgroup, - __trace_wb_cgroup_size(inode_to_wb(inode))) + __field(unsigned int, cgroup_ino) ), TP_fast_assign( @@ -619,16 +588,16 @@ TRACE_EVENT(writeback_sb_inodes_requeue, __entry->ino = inode->i_ino; __entry->state = inode->i_state; __entry->dirtied_when = inode->dirtied_when; - __trace_wb_assign_cgroup(__get_str(cgroup), inode_to_wb(inode)); + __entry->cgroup_ino = __trace_wb_assign_cgroup(inode_to_wb(inode)); ), - TP_printk("bdi %s: ino=%lu state=%s dirtied_when=%lu age=%lu cgroup=%s", + TP_printk("bdi %s: ino=%lu state=%s dirtied_when=%lu age=%lu cgroup_ino=%u", __entry->name, __entry->ino, show_inode_state(__entry->state), __entry->dirtied_when, (jiffies - __entry->dirtied_when) / HZ, - __get_str(cgroup) + __entry->cgroup_ino ) ); @@ -684,7 +653,7 @@ DECLARE_EVENT_CLASS(writeback_single_inode_template, __field(unsigned long, writeback_index) __field(long, nr_to_write) __field(unsigned long, wrote) - __dynamic_array(char, cgroup, __trace_wbc_cgroup_size(wbc)) + __field(unsigned int, cgroup_ino) ), TP_fast_assign( @@ -696,11 +665,11 @@ DECLARE_EVENT_CLASS(writeback_single_inode_template, __entry->writeback_index = inode->i_mapping->writeback_index; __entry->nr_to_write = nr_to_write; __entry->wrote = nr_to_write - wbc->nr_to_write; - __trace_wbc_assign_cgroup(__get_str(cgroup), wbc); + __entry->cgroup_ino = __trace_wbc_assign_cgroup(wbc); ), TP_printk("bdi %s: ino=%lu state=%s dirtied_when=%lu age=%lu " - "index=%lu to_write=%ld wrote=%lu cgroup=%s", + "index=%lu to_write=%ld wrote=%lu cgroup_ino=%u", __entry->name, __entry->ino, show_inode_state(__entry->state), @@ -709,7 +678,7 @@ DECLARE_EVENT_CLASS(writeback_single_inode_template, __entry->writeback_index, __entry->nr_to_write, __entry->wrote, - __get_str(cgroup) + __entry->cgroup_ino ) ); -- cgit v1.2.3