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* Merge tag 'trace-3.16' of ↵Linus Torvalds2014-06-1030-729/+1326
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "Lots of tweaks, small fixes, optimizations, and some helper functions to help out the rest of the kernel to ease their use of trace events. The big change for this release is the allowing of other tracers, such as the latency tracers, to be used in the trace instances and allow for function or function graph tracing to be in the top level simultaneously" * tag 'trace-3.16' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (44 commits) tracing: Fix memory leak on instance deletion tracing: Fix leak of ring buffer data when new instances creation fails tracing/kprobes: Avoid self tests if tracing is disabled on boot up tracing: Return error if ftrace_trace_arrays list is empty tracing: Only calculate stats of tracepoint benchmarks for 2^32 times tracing: Convert stddev into u64 in tracepoint benchmark tracing: Introduce saved_cmdlines_size file tracing: Add __get_dynamic_array_len() macro for trace events tracing: Remove unused variable in trace_benchmark tracing: Eliminate double free on failure of allocation on boot up ftrace/x86: Call text_ip_addr() instead of the duplicated code tracing: Print max callstack on stacktrace bug tracing: Move locking of trace_cmdline_lock into start/stop seq calls tracing: Try again for saved cmdline if failed due to locking tracing: Have saved_cmdlines use the seq_read infrastructure tracing: Add tracepoint benchmark tracepoint tracing: Print nasty banner when trace_printk() is in use tracing: Add funcgraph_tail option to print function name after closing braces tracing: Eliminate duplicate TRACE_GRAPH_PRINT_xx defines tracing: Add __bitmask() macro to trace events to cpumasks and other bitmasks ...
| * tracing: Fix memory leak on instance deletionSteven Rostedt (Red Hat)2014-06-071-2/+1
| | | | | | | | | | | | | | | | | | | | | | When an instance is created, it also gets a snapshot ring buffer allocated (with minimum of pages). But when it is deleted the snapshot buffer is not. There was a helper function added to match the allocation of these ring buffers to a way to free them, but it wasn't used by the deletion of an instance. Using that helper function solves this memory leak. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Fix leak of ring buffer data when new instances creation failsSteven Rostedt (Red Hat)2014-06-061-2/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Yoshihiro Yunomae reported that the ring buffer data for a trace instance does not get properly cleaned up when it fails. He proposed a patch that manually cleaned the data up and addad a bunch of labels. The labels are not needed because all trace array is allocated with a kzalloc which initializes it to 0 and all kfree()s can take a NULL pointer and will ignore it. Adding a new helper function free_trace_buffers() that can also take null buffers to free the buffers that were allocated by allocate_trace_buffers(). Link: http://lkml.kernel.org/r/20140605223522.32311.31664.stgit@yunodevel Reported-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing/kprobes: Avoid self tests if tracing is disabled on boot upYoshihiro YUNOMAE2014-06-061-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | If tracing is disabled on boot up, the kernel should not execute tracing self tests. The kernel should check whether tracing is disabled or not before executing any of the tracing self tests. Link: http://lkml.kernel.org/p/20140605223520.32311.56097.stgit@yunodevel Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Return error if ftrace_trace_arrays list is emptyYoshihiro YUNOMAE2014-06-062-0/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ftrace_trace_arrays links global_trace.list. However, global_trace is not added to ftrace_trace_arrays if trace_alloc_buffers() failed. As the result, ftrace_trace_arrays becomes an empty list. If ftrace_trace_arrays is an empty list, current top_trace_array() returns an invalid pointer. As the result, the kernel can induce memory corruption or panic. Current implementation does not check whether ftrace_trace_arrays is empty list or not. So, in this patch, if ftrace_trace_arrays is empty list, top_trace_array() returns NULL. Moreover, this patch makes all functions calling top_trace_array() handle it appropriately. Link: http://lkml.kernel.org/p/20140605223517.32311.99233.stgit@yunodevel Signed-off-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Only calculate stats of tracepoint benchmarks for 2^32 timesSteven Rostedt (Red Hat)2014-06-061-7/+30
| | | | | | | | | | | | | | | | | | When calculating the average and standard deviation, it is required that the count be less than UINT_MAX, otherwise the do_div() will get undefined results. After 2^32 counts of data, the average and standard deviation should pretty much be set anyway. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Convert stddev into u64 in tracepoint benchmarkSteven Rostedt (Red Hat)2014-06-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | I've been told that do_div() expects an unsigned 64 bit number, and is undefined if a signed is used. This gave a warning on the MIPS build. I'm not sure if a signed 64 bit dividend is really an issue or not, but the calculation this is used for is standard deviation, and that isn't going to be negative. We can just convert it to unsigned and be safe. Reported-by: David Daney <ddaney.cavm@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Introduce saved_cmdlines_size fileYoshihiro YUNOMAE2014-06-051-24/+154
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce saved_cmdlines_size file for changing the number of saved pid-comms. saved_cmdlines currently stores 128 command names using SAVED_CMDLINES, but 'no-existing processes' names are often lost in saved_cmdlines when we read the trace data. So, by introducing saved_cmdlines_size file, we can now change the 128 command names saved to something much larger if needed. When we write a value to saved_cmdlines_size, the number of the value will be stored in pid-comm list: # echo 1024 > /sys/kernel/debug/tracing/saved_cmdlines_size Here, 1024 command names can be stored. The default number is 128 and the maximum number is PID_MAX_DEFAULT (=32768 if CONFIG_BASE_SMALL is not set). So, if we want to avoid losing any command names, we need to set 32768 to saved_cmdlines_size. We can read the maximum number of the list: # cat /sys/kernel/debug/tracing/saved_cmdlines_size 128 Link: http://lkml.kernel.org/p/20140605012427.22115.16173.stgit@yunodevel Signed-off-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Add __get_dynamic_array_len() macro for trace eventsSteven Rostedt (Red Hat)2014-06-041-1/+10
| | | | | | | | | | | | | | | | | | | | | | If a trace event uses a dynamic array for something other than a string then there's currently no way the TP_printk() can figure out what size it is. A __get_dynamic_array_len() is required to know the length. This also simplifies the __get_bitmask() macro which required it as well, but instead just hardcoded it. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Remove unused variable in trace_benchmarkSteven Rostedt (Red Hat)2014-06-041-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Somehow this unused variable warning sneaked past my warnings check (probably due to it depending on a new config). kernel/trace/trace_benchmark.c: In function 'trace_do_benchmark': kernel/trace/trace_benchmark.c:38:6: warning: unused variable 'seedsq' [-Wunused-variable] u64 seedsq; ^ Link: http://lkml.kernel.org/r/20140604160921.4f4e69c4@canb.auug.org.au Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Eliminate double free on failure of allocation on boot upYoshihiro YUNOMAE2014-06-041-4/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | If allocation of the max_buffer fails on boot up, the error path will free both per_cpu data structures from the buffers. With the new redesign of the code, those structures are freed if allocations failed. That is, the helper function that allocates the buffers will free the per cpu data on failure. No need to do it again. In fact, the second free will cause a bug as the code can not handle a double free. Link: http://lkml.kernel.org/p/20140603042803.27308.30956.stgit@yunodevel Signed-off-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ftrace/x86: Call text_ip_addr() instead of the duplicated codePetr Mladek2014-06-041-10/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I just went over this when looking at some Xen-related ftrace initialization problems. They were related to Xen code that is not upstream but this clean up would make sense here. I think that this was already the intention when text_ip_addr() was introduced in the commit 87fbb2ac6073a703930 (ftrace/x86: Use breakpoints for converting function graph caller). Anyway, better do it now before it shots people into their leg ;-) Link: http://lkml.kernel.org/p/1401812601-2359-1-git-send-email-pmladek@suse.cz Signed-off-by: Petr Mladek <pmladek@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Print max callstack on stacktrace bugMinchan Kim2014-06-021-4/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While I played with my own feature(ex, something on the way to reclaim), the kernel would easily oops. I guessed that the reason had to do with stack overflow and wanted to prove it. I discovered the stack tracer which proved to be very useful for me but the kernel would oops before my user program gather the information via "watch cat /sys/kernel/debug/tracing/stack_trace" so I couldn't get any message from that. What I needed was to have the stack tracer emit the kernel stack usage before it does the oops so I could find what was hogging the stack. This patch shows the callstack of max stack usage right before an oops so we can find a culprit. So, the result is as follows. [ 1116.522206] init: lightdm main process (1246) terminated with status 1 [ 1119.922916] init: failsafe-x main process (1272) terminated with status 1 [ 3887.728131] kworker/u24:1 (6637) used greatest stack depth: 256 bytes left [ 6397.629227] cc1 (9554) used greatest stack depth: 128 bytes left [ 7174.467392] Depth Size Location (47 entries) [ 7174.467392] ----- ---- -------- [ 7174.467785] 0) 7248 256 get_page_from_freelist+0xa7/0x920 [ 7174.468506] 1) 6992 352 __alloc_pages_nodemask+0x1cd/0xb20 [ 7174.469224] 2) 6640 8 alloc_pages_current+0x10f/0x1f0 [ 7174.469413] 3) 6632 168 new_slab+0x2c5/0x370 [ 7174.469413] 4) 6464 8 __slab_alloc+0x3a9/0x501 [ 7174.469413] 5) 6456 80 __kmalloc+0x1cb/0x200 [ 7174.469413] 6) 6376 376 vring_add_indirect+0x36/0x200 [ 7174.469413] 7) 6000 144 virtqueue_add_sgs+0x2e2/0x320 [ 7174.469413] 8) 5856 288 __virtblk_add_req+0xda/0x1b0 [ 7174.469413] 9) 5568 96 virtio_queue_rq+0xd3/0x1d0 [ 7174.469413] 10) 5472 128 __blk_mq_run_hw_queue+0x1ef/0x440 [ 7174.469413] 11) 5344 16 blk_mq_run_hw_queue+0x35/0x40 [ 7174.469413] 12) 5328 96 blk_mq_insert_requests+0xdb/0x160 [ 7174.469413] 13) 5232 112 blk_mq_flush_plug_list+0x12b/0x140 [ 7174.469413] 14) 5120 112 blk_flush_plug_list+0xc7/0x220 [ 7174.469413] 15) 5008 64 io_schedule_timeout+0x88/0x100 [ 7174.469413] 16) 4944 128 mempool_alloc+0x145/0x170 [ 7174.469413] 17) 4816 96 bio_alloc_bioset+0x10b/0x1d0 [ 7174.469413] 18) 4720 48 get_swap_bio+0x30/0x90 [ 7174.469413] 19) 4672 160 __swap_writepage+0x150/0x230 [ 7174.469413] 20) 4512 32 swap_writepage+0x42/0x90 [ 7174.469413] 21) 4480 320 shrink_page_list+0x676/0xa80 [ 7174.469413] 22) 4160 208 shrink_inactive_list+0x262/0x4e0 [ 7174.469413] 23) 3952 304 shrink_lruvec+0x3e1/0x6a0 [ 7174.469413] 24) 3648 80 shrink_zone+0x3f/0x110 [ 7174.469413] 25) 3568 128 do_try_to_free_pages+0x156/0x4c0 [ 7174.469413] 26) 3440 208 try_to_free_pages+0xf7/0x1e0 [ 7174.469413] 27) 3232 352 __alloc_pages_nodemask+0x783/0xb20 [ 7174.469413] 28) 2880 8 alloc_pages_current+0x10f/0x1f0 [ 7174.469413] 29) 2872 200 __page_cache_alloc+0x13f/0x160 [ 7174.469413] 30) 2672 80 find_or_create_page+0x4c/0xb0 [ 7174.469413] 31) 2592 80 ext4_mb_load_buddy+0x1e9/0x370 [ 7174.469413] 32) 2512 176 ext4_mb_regular_allocator+0x1b7/0x460 [ 7174.469413] 33) 2336 128 ext4_mb_new_blocks+0x458/0x5f0 [ 7174.469413] 34) 2208 256 ext4_ext_map_blocks+0x70b/0x1010 [ 7174.469413] 35) 1952 160 ext4_map_blocks+0x325/0x530 [ 7174.469413] 36) 1792 384 ext4_writepages+0x6d1/0xce0 [ 7174.469413] 37) 1408 16 do_writepages+0x23/0x40 [ 7174.469413] 38) 1392 96 __writeback_single_inode+0x45/0x2e0 [ 7174.469413] 39) 1296 176 writeback_sb_inodes+0x2ad/0x500 [ 7174.469413] 40) 1120 80 __writeback_inodes_wb+0x9e/0xd0 [ 7174.469413] 41) 1040 160 wb_writeback+0x29b/0x350 [ 7174.469413] 42) 880 208 bdi_writeback_workfn+0x11c/0x480 [ 7174.469413] 43) 672 144 process_one_work+0x1d2/0x570 [ 7174.469413] 44) 528 112 worker_thread+0x116/0x370 [ 7174.469413] 45) 416 240 kthread+0xf3/0x110 [ 7174.469413] 46) 176 176 ret_from_fork+0x7c/0xb0 [ 7174.469413] ------------[ cut here ]------------ [ 7174.469413] kernel BUG at kernel/trace/trace_stack.c:174! [ 7174.469413] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC [ 7174.469413] Dumping ftrace buffer: [ 7174.469413] (ftrace buffer empty) [ 7174.469413] Modules linked in: [ 7174.469413] CPU: 0 PID: 440 Comm: kworker/u24:0 Not tainted 3.14.0+ #212 [ 7174.469413] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 7174.469413] Workqueue: writeback bdi_writeback_workfn (flush-253:0) [ 7174.469413] task: ffff880034170000 ti: ffff880029518000 task.ti: ffff880029518000 [ 7174.469413] RIP: 0010:[<ffffffff8112336e>] [<ffffffff8112336e>] stack_trace_call+0x2de/0x340 [ 7174.469413] RSP: 0000:ffff880029518290 EFLAGS: 00010046 [ 7174.469413] RAX: 0000000000000030 RBX: 000000000000002f RCX: 0000000000000000 [ 7174.469413] RDX: 0000000000000000 RSI: 000000000000002f RDI: ffffffff810b7159 [ 7174.469413] RBP: ffff8800295182f0 R08: ffffffffffffffff R09: 0000000000000000 [ 7174.469413] R10: 0000000000000001 R11: 0000000000000001 R12: ffffffff82768dfc [ 7174.469413] R13: 000000000000f2e8 R14: ffff8800295182b8 R15: 00000000000000f8 [ 7174.469413] FS: 0000000000000000(0000) GS:ffff880037c00000(0000) knlGS:0000000000000000 [ 7174.469413] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 7174.469413] CR2: 00002acd0b994000 CR3: 0000000001c0b000 CR4: 00000000000006f0 [ 7174.469413] Stack: [ 7174.469413] 0000000000000000 ffffffff8114fdb7 0000000000000087 0000000000001c50 [ 7174.469413] 0000000000000000 0000000000000000 0000000000000000 0000000000000000 [ 7174.469413] 0000000000000002 ffff880034170000 ffff880034171028 0000000000000000 [ 7174.469413] Call Trace: [ 7174.469413] [<ffffffff8114fdb7>] ? get_page_from_freelist+0xa7/0x920 [ 7174.469413] [<ffffffff816eee3f>] ftrace_call+0x5/0x2f [ 7174.469413] [<ffffffff81165065>] ? next_zones_zonelist+0x5/0x70 [ 7174.469413] [<ffffffff810a23fa>] ? __bfs+0x11a/0x270 [ 7174.469413] [<ffffffff81165065>] ? next_zones_zonelist+0x5/0x70 [ 7174.469413] [<ffffffff8114fdb7>] ? get_page_from_freelist+0xa7/0x920 [ 7174.469413] [<ffffffff8119092f>] ? alloc_pages_current+0x10f/0x1f0 [ 7174.469413] [<ffffffff811507fd>] __alloc_pages_nodemask+0x1cd/0xb20 [ 7174.469413] [<ffffffff810a4de6>] ? check_irq_usage+0x96/0xe0 [ 7174.469413] [<ffffffff816eee3f>] ? ftrace_call+0x5/0x2f [ 7174.469413] [<ffffffff8119092f>] alloc_pages_current+0x10f/0x1f0 [ 7174.469413] [<ffffffff81199cd5>] ? new_slab+0x2c5/0x370 [ 7174.469413] [<ffffffff81199cd5>] new_slab+0x2c5/0x370 [ 7174.469413] [<ffffffff816eee3f>] ? ftrace_call+0x5/0x2f [ 7174.469413] [<ffffffff816db002>] __slab_alloc+0x3a9/0x501 [ 7174.469413] [<ffffffff8119af8b>] ? __kmalloc+0x1cb/0x200 [ 7174.469413] [<ffffffff8141dc46>] ? vring_add_indirect+0x36/0x200 [ 7174.469413] [<ffffffff8141dc46>] ? vring_add_indirect+0x36/0x200 [ 7174.469413] [<ffffffff8141dc46>] ? vring_add_indirect+0x36/0x200 [ 7174.469413] [<ffffffff8119af8b>] __kmalloc+0x1cb/0x200 [ 7174.469413] [<ffffffff8141de10>] ? vring_add_indirect+0x200/0x200 [ 7174.469413] [<ffffffff8141dc46>] vring_add_indirect+0x36/0x200 [ 7174.469413] [<ffffffff8141e402>] virtqueue_add_sgs+0x2e2/0x320 [ 7174.469413] [<ffffffff8148e35a>] __virtblk_add_req+0xda/0x1b0 [ 7174.469413] [<ffffffff8148e503>] virtio_queue_rq+0xd3/0x1d0 [ 7174.469413] [<ffffffff8134aa0f>] __blk_mq_run_hw_queue+0x1ef/0x440 [ 7174.469413] [<ffffffff8134b0d5>] blk_mq_run_hw_queue+0x35/0x40 [ 7174.469413] [<ffffffff8134b7bb>] blk_mq_insert_requests+0xdb/0x160 [ 7174.469413] [<ffffffff8134be5b>] blk_mq_flush_plug_list+0x12b/0x140 [ 7174.469413] [<ffffffff81342237>] blk_flush_plug_list+0xc7/0x220 [ 7174.469413] [<ffffffff816e60ef>] ? _raw_spin_unlock_irqrestore+0x3f/0x70 [ 7174.469413] [<ffffffff816e16e8>] io_schedule_timeout+0x88/0x100 [ 7174.469413] [<ffffffff816e1665>] ? io_schedule_timeout+0x5/0x100 [ 7174.469413] [<ffffffff81149415>] mempool_alloc+0x145/0x170 [ 7174.469413] [<ffffffff8109baf0>] ? __init_waitqueue_head+0x60/0x60 [ 7174.469413] [<ffffffff811e246b>] bio_alloc_bioset+0x10b/0x1d0 [ 7174.469413] [<ffffffff81184230>] ? end_swap_bio_read+0xc0/0xc0 [ 7174.469413] [<ffffffff81184230>] ? end_swap_bio_read+0xc0/0xc0 [ 7174.469413] [<ffffffff81184110>] get_swap_bio+0x30/0x90 [ 7174.469413] [<ffffffff81184230>] ? end_swap_bio_read+0xc0/0xc0 [ 7174.469413] [<ffffffff81184660>] __swap_writepage+0x150/0x230 [ 7174.469413] [<ffffffff810ab405>] ? do_raw_spin_unlock+0x5/0xa0 [ 7174.469413] [<ffffffff81184230>] ? end_swap_bio_read+0xc0/0xc0 [ 7174.469413] [<ffffffff81184515>] ? __swap_writepage+0x5/0x230 [ 7174.469413] [<ffffffff81184782>] swap_writepage+0x42/0x90 [ 7174.469413] [<ffffffff8115ae96>] shrink_page_list+0x676/0xa80 [ 7174.469413] [<ffffffff816eee3f>] ? ftrace_call+0x5/0x2f [ 7174.469413] [<ffffffff8115b872>] shrink_inactive_list+0x262/0x4e0 [ 7174.469413] [<ffffffff8115c1c1>] shrink_lruvec+0x3e1/0x6a0 [ 7174.469413] [<ffffffff8115c4bf>] shrink_zone+0x3f/0x110 [ 7174.469413] [<ffffffff816eee3f>] ? ftrace_call+0x5/0x2f [ 7174.469413] [<ffffffff8115c9e6>] do_try_to_free_pages+0x156/0x4c0 [ 7174.469413] [<ffffffff8115cf47>] try_to_free_pages+0xf7/0x1e0 [ 7174.469413] [<ffffffff81150db3>] __alloc_pages_nodemask+0x783/0xb20 [ 7174.469413] [<ffffffff8119092f>] alloc_pages_current+0x10f/0x1f0 [ 7174.469413] [<ffffffff81145c0f>] ? __page_cache_alloc+0x13f/0x160 [ 7174.469413] [<ffffffff81145c0f>] __page_cache_alloc+0x13f/0x160 [ 7174.469413] [<ffffffff81146c6c>] find_or_create_page+0x4c/0xb0 [ 7174.469413] [<ffffffff811463e5>] ? find_get_page+0x5/0x130 [ 7174.469413] [<ffffffff812837b9>] ext4_mb_load_buddy+0x1e9/0x370 [ 7174.469413] [<ffffffff81284c07>] ext4_mb_regular_allocator+0x1b7/0x460 [ 7174.469413] [<ffffffff81281070>] ? ext4_mb_use_preallocated+0x40/0x360 [ 7174.469413] [<ffffffff816eee3f>] ? ftrace_call+0x5/0x2f [ 7174.469413] [<ffffffff81287eb8>] ext4_mb_new_blocks+0x458/0x5f0 [ 7174.469413] [<ffffffff8127d83b>] ext4_ext_map_blocks+0x70b/0x1010 [ 7174.469413] [<ffffffff8124e6d5>] ext4_map_blocks+0x325/0x530 [ 7174.469413] [<ffffffff81253871>] ext4_writepages+0x6d1/0xce0 [ 7174.469413] [<ffffffff812531a0>] ? ext4_journalled_write_end+0x330/0x330 [ 7174.469413] [<ffffffff811539b3>] do_writepages+0x23/0x40 [ 7174.469413] [<ffffffff811d2365>] __writeback_single_inode+0x45/0x2e0 [ 7174.469413] [<ffffffff811d36ed>] writeback_sb_inodes+0x2ad/0x500 [ 7174.469413] [<ffffffff811d39de>] __writeback_inodes_wb+0x9e/0xd0 [ 7174.469413] [<ffffffff811d40bb>] wb_writeback+0x29b/0x350 [ 7174.469413] [<ffffffff81057c3d>] ? __local_bh_enable_ip+0x6d/0xd0 [ 7174.469413] [<ffffffff811d6e9c>] bdi_writeback_workfn+0x11c/0x480 [ 7174.469413] [<ffffffff81070610>] ? process_one_work+0x170/0x570 [ 7174.469413] [<ffffffff81070672>] process_one_work+0x1d2/0x570 [ 7174.469413] [<ffffffff81070610>] ? process_one_work+0x170/0x570 [ 7174.469413] [<ffffffff81071bb6>] worker_thread+0x116/0x370 [ 7174.469413] [<ffffffff81071aa0>] ? manage_workers.isra.19+0x2e0/0x2e0 [ 7174.469413] [<ffffffff81078e53>] kthread+0xf3/0x110 [ 7174.469413] [<ffffffff81078d60>] ? flush_kthread_worker+0x150/0x150 [ 7174.469413] [<ffffffff816ef0ec>] ret_from_fork+0x7c/0xb0 [ 7174.469413] [<ffffffff81078d60>] ? flush_kthread_worker+0x150/0x150 [ 7174.469413] Code: c0 49 bc fc 8d 76 82 ff ff ff ff e8 44 5a 5b 00 31 f6 8b 05 95 2b b3 00 48 39 c6 7d 0e 4c 8b 04 f5 20 5f c5 81 49 83 f8 ff 75 11 <0f> 0b 48 63 05 71 5a 64 01 48 29 c3 e9 d0 fd ff ff 48 8d 5e 01 [ 7174.469413] RIP [<ffffffff8112336e>] stack_trace_call+0x2de/0x340 [ 7174.469413] RSP <ffff880029518290> [ 7174.469413] ---[ end trace c97d325b36b718f3 ]--- Link: http://lkml.kernel.org/p/1401683592-1651-1-git-send-email-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Move locking of trace_cmdline_lock into start/stop seq callsSteven Rostedt (Red Hat)2014-05-301-4/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | With the conversion of the saved_cmdlines output to use seq_read, there is now a race between accessing the values of the saved_cmdlines and the writing to them. The trace_cmdline_lock needs to be taken at the start and stop of the seq calls. A new __trace_find_cmdline() call is created to allow for the look up to happen without taking the lock. Fixes: 42584c81c5ad tracing: Have saved_cmdlines use the seq_read infrastructure Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Try again for saved cmdline if failed due to lockingSteven Rostedt (Red Hat)2014-05-301-6/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to prevent the saved cmdline cache from being filled when tracing is not active, the comms are only recorded after a trace event is recorded. The problem is, a comm can fail to be recorded if the trace_cmdline_lock is held. That lock is taken via a trylock to allow it to happen from any context (including NMI). If the lock fails to be taken, the comm is skipped. No big deal, as we will try again later. But! Because of the code that was added to only record after an event, we may not try again later as the recording is made as a oneshot per event per CPU. Only disable the recording of the comm if the comm is actually recorded. Fixes: 7ffbd48d5cab "tracing: Cache comms only after an event occurred" Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Have saved_cmdlines use the seq_read infrastructureYoshihiro YUNOMAE2014-05-301-35/+54
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Current tracing_saved_cmdlines_read() implementation is naive; It allocates a large buffer, constructs output data to that buffer for each read operation, and then copies a portion of the buffer to the user space buffer. This has several issues such as slow memory allocation, high CPU usage, and even corruption of the output data. The seq_read infrastructure is made to handle this type of work. By converting it to use seq_read() the code becomes smaller, simplified, as well as correct. Link: http://lkml.kernel.org/p/20140220084431.3839.51793.stgit@yunodevel Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: linux-kernel@vger.kernel.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Add tracepoint benchmark tracepointSteven Rostedt (Red Hat)2014-05-304-0/+250
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to help benchmark the time tracepoints take, a new config option is added called CONFIG_TRACEPOINT_BENCHMARK. When this option is set a tracepoint is created called "benchmark:benchmark_event". When the tracepoint is enabled, it kicks off a kernel thread that goes into an infinite loop (calling cond_sched() to let other tasks run), and calls the tracepoint. Each iteration will record the time it took to write to the tracepoint and the next iteration that data will be passed to the tracepoint itself. That is, the tracepoint will report the time it took to do the previous tracepoint. The string written to the tracepoint is a static string of 128 bytes to keep the time the same. The initial string is simply a write of "START". The second string records the cold cache time of the first write which is not added to the rest of the calculations. As it is a tight loop, it benchmarks as hot cache. That's fine because we care most about hot paths that are probably in cache already. An example of the output: START first=3672 [COLD CACHED] last=632 first=3672 max=632 min=632 avg=316 std=446 std^2=199712 last=278 first=3672 max=632 min=278 avg=303 std=316 std^2=100337 last=277 first=3672 max=632 min=277 avg=296 std=258 std^2=67064 last=273 first=3672 max=632 min=273 avg=292 std=224 std^2=50411 last=273 first=3672 max=632 min=273 avg=288 std=200 std^2=40389 last=281 first=3672 max=632 min=273 avg=287 std=183 std^2=33666 Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Print nasty banner when trace_printk() is in useSteven Rostedt2014-05-301-1/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | trace_printk() is used to debug fast paths within the kernel. Places that gets called in any context (interrupt or NMI) or thousands of times a second. Something you do not want to do with a printk(). In order to make it completely lockless as it needs a temporary buffer to handle some of the string formatting, a page is created per cpu for every context (four per cpu; normal, softirq, irq, NMI). Since trace_printk() should only be used for debugging purposes, there's no reason to waste memory on these buffers on a production system. That means, trace_printk() should never be used unless a developer is debugging their kernel. There's macro magic to allocate the buffers if trace_printk() is used anywhere in the kernel. To help enforce that trace_printk() isn't used outside of development, when it is used, a nasty banner is displayed on bootup (or when a module is loaded that uses trace_printk() and the kernel core does not). Here's the banner: ********************************************************** ** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE ** ** ** ** trace_printk() being used. Allocating extra memory. ** ** ** ** This means that this is a DEBUG kernel and it is ** ** unsafe for produciton use. ** ** ** ** If you see this message and you are not debugging ** ** the kernel, report this immediately to your vendor! ** ** ** ** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE ** ********************************************************** That should hopefully keep developers from trying to sneak in a trace_printk() or two. Link: http://lkml.kernel.org/p/20140528131440.2283213c@gandalf.local.home Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Add funcgraph_tail option to print function name after closing bracesRobert Elliott2014-05-213-3/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the function-graph tracer, add a funcgraph_tail option to print the function name on all } lines, not just functions whose first line is no longer in the trace buffer. If a function calls other traced functions, its total time appears on its } line. This change allows grep to be used to determine the function for which the line corresponds. Update Documentation/trace/ftrace.txt to describe this new option. Link: http://lkml.kernel.org/p/20140520221041.8359.6782.stgit@beardog.cce.hp.com Signed-off-by: Robert Elliott <elliott@hp.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Eliminate duplicate TRACE_GRAPH_PRINT_xx definesRobert Elliott2014-05-212-9/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Eliminate duplicate TRACE_GRAPH_PRINT_xx defines in trace_functions_graph.c that are already in trace.h. Add TRACE_GRAPH_PRINT_IRQS to trace.h, which is the only one that is missing. Link: http://lkml.kernel.org/p/20140520221031.8359.24733.stgit@beardog.cce.hp.com Signed-off-by: Robert Elliott <elliott@hp.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Add __bitmask() macro to trace events to cpumasks and other bitmasksSteven Rostedt (Red Hat)2014-05-154-1/+110
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Being able to show a cpumask of events can be useful as some events may affect only some CPUs. There is no standard way to record the cpumask and converting it to a string is rather expensive during the trace as traces happen in hotpaths. It would be better to record the raw event mask and be able to parse it at print time. The following macros were added for use with the TRACE_EVENT() macro: __bitmask() __assign_bitmask() __get_bitmask() To test this, I added this to the sched_migrate_task event, which looked like this: TRACE_EVENT(sched_migrate_task, TP_PROTO(struct task_struct *p, int dest_cpu, const struct cpumask *cpus), TP_ARGS(p, dest_cpu, cpus), TP_STRUCT__entry( __array( char, comm, TASK_COMM_LEN ) __field( pid_t, pid ) __field( int, prio ) __field( int, orig_cpu ) __field( int, dest_cpu ) __bitmask( cpumask, num_possible_cpus() ) ), TP_fast_assign( memcpy(__entry->comm, p->comm, TASK_COMM_LEN); __entry->pid = p->pid; __entry->prio = p->prio; __entry->orig_cpu = task_cpu(p); __entry->dest_cpu = dest_cpu; __assign_bitmask(cpumask, cpumask_bits(cpus), num_possible_cpus()); ), TP_printk("comm=%s pid=%d prio=%d orig_cpu=%d dest_cpu=%d cpumask=%s", __entry->comm, __entry->pid, __entry->prio, __entry->orig_cpu, __entry->dest_cpu, __get_bitmask(cpumask)) ); With the output of: ksmtuned-3613 [003] d..2 485.220508: sched_migrate_task: comm=ksmtuned pid=3615 prio=120 orig_cpu=3 dest_cpu=2 cpumask=00000000,0000000f migration/1-13 [001] d..5 485.221202: sched_migrate_task: comm=ksmtuned pid=3614 prio=120 orig_cpu=1 dest_cpu=0 cpumask=00000000,0000000f awk-3615 [002] d.H5 485.221747: sched_migrate_task: comm=rcu_preempt pid=7 prio=120 orig_cpu=0 dest_cpu=1 cpumask=00000000,000000ff migration/2-18 [002] d..5 485.222062: sched_migrate_task: comm=ksmtuned pid=3615 prio=120 orig_cpu=2 dest_cpu=3 cpumask=00000000,0000000f Link: http://lkml.kernel.org/r/1399377998-14870-6-git-send-email-javi.merino@arm.com Link: http://lkml.kernel.org/r/20140506132238.22e136d1@gandalf.local.home Suggested-by: Javi Merino <javi.merino@arm.com> Tested-by: Javi Merino <javi.merino@arm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ftrace/x86: Move the mcount/fentry code out of entry_64.SSteven Rostedt2014-05-143-204/+218
| | | | | | | | | | | | | | | | | | | | | | | | As the mcount code gets more complex, it really does not belong in the entry.S file. By moving it into its own file "mcount.S" keeps things a bit cleaner. Link: http://lkml.kernel.org/p/20140508152152.2130e8cf@gandalf.local.home Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ftrace: Remove FTRACE_UPDATE_MODIFY_CALL_REGS flagSteven Rostedt (Red Hat)2014-05-143-14/+4
| | | | | | | | | | | | | | | | | | | | | | | | As the decision to what needs to be done (converting a call to the ftrace_caller to ftrace_caller_regs or to convert from ftrace_caller_regs to ftrace_caller) can easily be determined from the rec->flags of FTRACE_FL_REGS and FTRACE_FL_REGS_EN, there's no need to have the ftrace_check_record() return either a UPDATE_MODIFY_CALL_REGS or a UPDATE_MODIFY_CALL. Just he latter is enough. This added flag causes more complexity than is required. Remove it. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ftrace: Use the ftrace_addr helper functions to find the ftrace_addrSteven Rostedt (Red Hat)2014-05-141-10/+5
| | | | | | | | | | | | | | | | | | With the moving of the functions that determine what the mcount call site should be replaced with into the generic code, there is a few places in the generic code that can use them instead of hard coding it as it does. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ftrace: Make get_ftrace_addr() and get_ftrace_addr_old() globalSteven Rostedt (Red Hat)2014-05-143-31/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move and rename get_ftrace_addr() and get_ftrace_addr_old() to ftrace_get_addr_new() and ftrace_get_addr_curr() respectively. This moves these two helper functions in the generic code out from the arch specific code, and renames them to have a better generic name. This will allow other archs to use them as well as makes it a bit easier to work on getting separate trampolines for different functions. ftrace_get_addr_new() returns the trampoline address that the mcount call address will be converted to. ftrace_get_addr_curr() returns the trampoline address of what the mcount call address currently jumps to. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ftrace/x86: Get the current mcount addr for add_breakpoint()Steven Rostedt (Red Hat)2014-05-141-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | The add_breakpoint() code in the ftrace updating gets the address of what the call will become, but if the mcount address is changing from regs to non-regs ftrace_caller or vice versa, it will use what the record currently is. This is rather silly as the code should always use what is currently there regardless of if it's changing the regs function or just converting to a nop. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ftrace: Always inline ftrace_hash_empty() helper functionSteven Rostedt (Red Hat)2014-05-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The ftrace_hash_empty() function is a simple test: return !hash || !hash->count; But gcc seems to want to make it a call. As this is in an extreme hot path of the function tracer, there's no reason it needs to be a call. I only wrote it to be a helper function anyway, otherwise it would have been inlined manually. Force gcc to inline it, as it could have also been a macro. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ftrace: Write in missing comment from a very old commitSteven Rostedt (Red Hat)2014-05-141-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Back in 2011 Commit ed926f9b35cda "ftrace: Use counters to enable functions to trace" changed the way ftrace accounts for enabled and disabled traced functions. There was a comment started as: /* * */ But never finished. Well, that's rather useless. I probably forgot to save the file before committing it. And it passed review from all this time. Anyway, better late than never. I updated the comment to express what is happening in that somewhat complex code. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ftrace: Remove boolean of hash_enable and hash_disableSteven Rostedt (Red Hat)2014-05-141-6/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 4104d326b670 "ftrace: Remove global function list and call function directly" cleaned up the global_ops filtering and made the code simpler, but it left a variable "hash_enable" that was used to know if the hash functions should be updated or not. It was updated if the global_ops did not override them. As the global_ops are now no different than any other ftrace_ops, the hash always gets updated and there's no reason to use the hash_enable boolean. The same goes for hash_disable used in ftrace_shutdown(). Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Add trace_<tracepoint>_enabled() functionSteven Rostedt (Red Hat)2014-05-072-0/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are some code paths in the kernel that need to do some preparations before it calls a tracepoint. As that code is worthless overhead when the tracepoint is not enabled, it would be prudent to have that code only run when the tracepoint is active. To accomplish this, all tracepoints now get a static inline function called "trace_<tracepoint-name>_enabled()" which returns true when the tracepoint is enabled and false otherwise. As an added bonus, that function uses the static_key of the tracepoint such that no branch is needed. if (trace_mytracepoint_enabled()) { arg = process_tp_arg(); trace_mytracepoint(arg); } Will keep the "process_tp_arg()" (which may be expensive to run) from being executed when the tracepoint isn't enabled. It's best to encapsulate the tracepoint itself in the if statement just to keep races. For example, if you had: if (trace_mytracepoint_enabled()) arg = process_tp_arg(); trace_mytracepoint(arg); There's a chance that the tracepoint could be enabled just after the if statement, and arg will be undefined when calling the tracepoint. Link: http://lkml.kernel.org/r/20140506094407.507b6435@gandalf.local.home Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Replace __get_cpu_var uses with this_cpu_ptrChristoph Lameter2014-05-063-4/+4
| | | | | | | | | | | | | | | | | | | | Replace uses of &__get_cpu_var for address calculation with this_cpu_ptr. Link: http://lkml.kernel.org/p/alpine.DEB.2.10.1404291415560.18364@gentwo.org Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Remove myself as a tracing maintainerFrederic Weisbecker2014-05-051-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It has been a while since I last sent a tracing patch. I always keep an eye on tracing evolutions and contributions in general but given how busy I am with nohz, isolation and more generally core cleanups stuff, I seldom have time left to provide deep reviews of tracing patches nor simply for reviews to begin with. I've been very lucky to start kernel development on a very young subsystem with tons of low hanging fruits back in 2008. Given that it deals with a lot of tricky stuffs all around (sched, timers, irq, preemption, NMIs, SMP, RCU, ....) I basically learned everything there. Steve has been doing most of the incredible work these last years. Thanks a lot! Of course consider me always available to help on tracing if any hard days happen. Link: http://lkml.kernel.org/p/1399131991-13216-1-git-send-email-fweisbec@gmail.com Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ftrace: Have function graph tracer use global_ops for filteringSteven Rostedt (Red Hat)2014-05-021-8/+6
| | | | | | | | | | | | | | | | | | | | | | Commit 4104d326b670 "ftrace: Remove global function list and call function directly" cleaned up the global_ops filtering and made the code simpler. But it left out function graph filtering which also depended on that code. The function graph filtering still needs to use global_ops as the filter otherwise it wont filter at all. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Remove mock up poll wait functionSteven Rostedt (Red Hat)2014-04-306-34/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that the ring buffer has a built in way to wake up readers when there's data, using irq_work such that it is safe to do it in any context. But it was still using the old "poor man's" wait polling that checks every 1/10 of a second to see if it should wake up a waiter. This makes the latency for a wake up excruciatingly long. No need to do that anymore. Completely remove the different wait_poll types from the tracers and have them all use the default one now. Reported-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Break out of tracing_wait_pipe() before wait_pipe() is calledSteven Rostedt (Red Hat)2014-04-291-9/+9
| | | | | | | | | | | | | | | | | | | | | | | | When reading from trace_pipe, if tracing is off but nothing was read it should block. If something is read and tracing is off, then EOF is returned. If tracing is on and there's nothing to read, it will block. But because the check of whether tracing is off and something was read is done after the block on the pipe, it is hit or miss if the EOF is returned or not leading to inconsistent behavior. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Fix documentation of ftrace_set_global_{filter,notrace}()Jiaxing Wang2014-04-241-4/+2
| | | | | | | | | | | | | | | | | | | | | | The functions ftrace_set_global_filter() and ftrace_set_global_notrace() still have their old names in the kernel doc (ftrace_set_filter and ftrace_set_notrace respectively). Replace these with the real names. Link: http://lkml.kernel.org/p/1398006644-5935-3-git-send-email-wangjiaxing@insigma.com.cn Signed-off-by: Jiaxing Wang <wangjiaxing@insigma.com.cn> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing/stack_trace: Skip 4 instead of 3 when using ftrace_ops_list_funcJiaxing Wang2014-04-243-2/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When using ftrace_ops_list_func, we should skip 4 instead of 3, to avoid ftrace_call+0x5/0xb appearing in the stack trace: Depth Size Location (110 entries) ----- ---- -------- 0) 2956 0 update_curr+0xe/0x1e0 1) 2956 68 ftrace_call+0x5/0xb 2) 2888 92 enqueue_entity+0x53/0xe80 3) 2796 80 enqueue_task_fair+0x47/0x7e0 4) 2716 28 enqueue_task+0x45/0x70 5) 2688 12 activate_task+0x22/0x30 Add a function using_ftrace_ops_list_func() to test for this while keeping ftrace_ops_list_func to remain static. Link: http://lkml.kernel.org/p/1398006644-5935-2-git-send-email-wangjiaxing@insigma.com.cn Signed-off-by: Jiaxing Wang <wangjiaxing@insigma.com.cn> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Add static to local functionsFabian Frederick2014-04-212-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | This patch adds static to the following functions: -cycle_t buffer_ftrace_now -void free_snapshot -int trace_selftest_startup_dynamic_tracing Link: http://lkml.kernel.org/p/20140417214442.d7abc7c0b0e4b90e7fedecc9@skynet.be Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ftrace: Statically initialize pm notifier blockMathias Krause2014-04-211-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of initializing the pm notifier block in register_ftrace_graph(), initialize it statically. This safes us some code. Found in the PaX patch, written by the PaX Team. Link: http://lkml.kernel.org/p/1396186310-3156-1-git-send-email-minipli@googlemail.com Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: PaX Team <pageexec@freemail.hu> Signed-off-by: Mathias Krause <minipli@googlemail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ftrace/x86: Fix order of warning messages when ftrace modifies codePetr Mladek2014-04-211-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | The colon at the end of the printk message suggests that it should get printed before the details printed by ftrace_bug(). When touching the line, let's use the preferred pr_warn() macro as suggested by checkpatch.pl. Link: http://lkml.kernel.org/r/1392650573-3390-5-git-send-email-pmladek@suse.cz Signed-off-by: Petr Mladek <pmladek@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Allow irq/preempt tracers to be used by instancesSteven Rostedt (Red Hat)2014-04-211-7/+17
| | | | | | | | | | | | | | | | | | The irqsoff, preemptoff and preemptirqsoff tracers can now be used by instances. But they may only be used by one instance at a time (including the top level directory). This allows multiple tracers to run while the irqsoff (and friends) tracer is running simultaneously. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Allow wakeup tracers to be used by instancesSteven Rostedt (Red Hat)2014-04-211-0/+16
| | | | | | | | | | | | | | | | | | The wakeup and wakeup_rt tracers can now be used by instances. But they may only be used by one instance at a time (including the top level directory). This allows multiple tracers to run while the wakeup tracer is running simultaneously. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Move ftrace_max_lock into trace_arraySteven Rostedt (Red Hat)2014-04-213-28/+30
| | | | | | | | | | | | | | | | In preparation for having tracers enabled in instances, the max_lock should be unique as updating the max for one tracer is a separate operation than updating it for another tracer using a different max. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Move tracing_max_latency into trace_arraySteven Rostedt (Red Hat)2014-04-215-36/+33
| | | | | | | | | | | | | | | | In preparation for letting the latency tracers be used by instances, remove the global tracing_max_latency variable and add a max_latency field to the trace_array that the latency tracers will now use. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ftrace: Remove global function list and call function directlySteven Rostedt (Red Hat)2014-04-218-221/+133
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of having a list of global functions that are called, as only one global function is allow to be enabled at a time, there's no reason to have a list. Instead, simply have all the users of the global ops, use the global ops directly, instead of registering their own ftrace_ops. Just switch what function is used before enabling the function tracer. This removes a lot of code as well as the complexity involved with it. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | Merge branch 'for-3.16' of ↵Linus Torvalds2014-06-1022-1004/+1966
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: "A lot of activities on cgroup side. Heavy restructuring including locking simplification took place to improve the code base and enable implementation of the unified hierarchy, which currently exists behind a __DEVEL__ mount option. The core support is mostly complete but individual controllers need further work. To explain the design and rationales of the the unified hierarchy Documentation/cgroups/unified-hierarchy.txt is added. Another notable change is css (cgroup_subsys_state - what each controller uses to identify and interact with a cgroup) iteration update. This is part of continuing updates on css object lifetime and visibility. cgroup started with reference count draining on removal way back and is now reaching a point where csses behave and are iterated like normal refcnted objects albeit with some complexities to allow distinguishing the state where they're being deleted. The css iteration update isn't taken advantage of yet but is planned to be used to simplify memcg significantly" * 'for-3.16' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (77 commits) cgroup: disallow disabled controllers on the default hierarchy cgroup: don't destroy the default root cgroup: disallow debug controller on the default hierarchy cgroup: clean up MAINTAINERS entries cgroup: implement css_tryget() device_cgroup: use css_has_online_children() instead of has_children() cgroup: convert cgroup_has_live_children() into css_has_online_children() cgroup: use CSS_ONLINE instead of CGRP_DEAD cgroup: iterate cgroup_subsys_states directly cgroup: introduce CSS_RELEASED and reduce css iteration fallback window cgroup: move cgroup->serial_nr into cgroup_subsys_state cgroup: link all cgroup_subsys_states in their sibling lists cgroup: move cgroup->sibling and ->children into cgroup_subsys_state cgroup: remove cgroup->parent device_cgroup: remove direct access to cgroup->children memcg: update memcg_has_children() to use css_next_child() memcg: remove tasks/children test from mem_cgroup_force_empty() cgroup: remove css_parent() cgroup: skip refcnting on normal root csses and cgrp_dfl_root self css cgroup: use cgroup->self.refcnt for cgroup refcnting ...
| * | cgroup: disallow disabled controllers on the default hierarchyLi Zefan2014-06-051-5/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After booting with cgroup_disable=memory, I still saw memcg files in the default hierarchy, and I can write to them, though it won't take effect. # dmesg ... Disabling memory control group subsystem ... # mount -t cgroup -o __DEVEL__sane_behavior xxx /cgroup # ls /cgroup ... memory.failcnt memory.move_charge_at_immigrate memory.force_empty memory.numa_stat memory.limit_in_bytes memory.oom_control ... # cat /cgroup/memory.usage_in_bytes 0 tj: Minor comment update. Signed-off-by: Li Zefan <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * | cgroup: don't destroy the default rootLi Zefan2014-06-051-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The default root is allocated and initialized at boot phase, so we shouldn't destroy the default root when it's umounted, otherwise it will lead to disaster. Just try mount and then umount the default root, and the kernel will crash immediately. v2: - No need to check for CSS_NO_REF in cgroup_get/put(). (Tejun) - Better call cgroup_put() for the default root in kill_sb(). (Tejun) - Add a comment. Signed-off-by: Li Zefan <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * | cgroup: disallow debug controller on the default hierarchyTejun Heo2014-05-193-7/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The debug controller, as its name suggests, exposes cgroup core internals to userland to aid debugging. Unfortunately, except for the name, there's no provision to prevent its usage in production configurations and the controller is widely enabled and mounted leaking internal details to userland. Like most other debug information, the information exposed by debug isn't interesting even for debugging itself once the related parts are working reliably. This controller has no reason for existing. This patch implements cgrp_dfl_root_inhibit_ss_mask which can suppress specific subsystems on the default hierarchy and adds the debug subsystem to it so that it can be gradually deprecated as usages move towards the unified hierarchy. Signed-off-by: Tejun Heo <tj@kernel.org>
| * | cgroup: clean up MAINTAINERS entriesTejun Heo2014-05-191-25/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are currently three cgroup related entries in MAINTAINERS. Make the following updates. * Make the names - both cgroup and cpuset - singular. We're mixing singular and plural all over the place for no good reason. * Drop containers@lists.linux-foundation.org from CGROUP. That list doesn't have much to do with cgroup per-se. * Add Documentation field to CGROUP. * Drop mm/*cgroup* from CGROUP. memcg has separate maintainers. * Prefix the controller-specific ones with "CONTROL CGROUP -" and collect cgroup related entries under the core one. * Add (MEMCG) abbreviation to MEMCG entry. * Drop Balbir Singh and KAMEZAWA Hiroyuki from memcg maintainers. It has been quite a while since both actually worked on memcg. Signed-off-by: Tejun Heo <tj@kernel.org>
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