- 02 Jun, 2014 1 commit
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Minchan Kim authored
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.orgSigned-off-by:
Minchan Kim <minchan@kernel.org> Signed-off-by:
Steven Rostedt <rostedt@goodmis.org>
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- 30 May, 2014 5 commits
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Steven Rostedt (Red Hat) authored
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: 42584c81 tracing: Have saved_cmdlines use the seq_read infrastructure Signed-off-by:
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Steven Rostedt (Red Hat) authored
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: 7ffbd48d "tracing: Cache comms only after an event occurred" Signed-off-by:
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Yoshihiro YUNOMAE authored
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@yunodevelSigned-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:
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Steven Rostedt (Red Hat) authored
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 authored
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.homeSigned-off-by:
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- 21 May, 2014 2 commits
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Robert Elliott authored
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.comSigned-off-by:
Robert Elliott <elliott@hp.com> Signed-off-by:
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Robert Elliott authored
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.comSigned-off-by:
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- 15 May, 2014 1 commit
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Steven Rostedt (Red Hat) authored
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.homeSuggested-by:Javi Merino <javi.merino@arm.com> Tested-by:
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- 14 May, 2014 8 commits
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Steven Rostedt authored
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.homeAcked-by:
Thomas Gleixner <tglx@linutronix.de> Acked-by:
Jiri Kosina <jkosina@suse.cz> Signed-off-by:
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Steven Rostedt (Red Hat) authored
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 (Red Hat) authored
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 (Red Hat) authored
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 (Red Hat) authored
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 (Red Hat) authored
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 (Red Hat) authored
Back in 2011 Commit ed926f9b "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:
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Steven Rostedt (Red Hat) authored
Commit 4104d326 "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:
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- 07 May, 2014 1 commit
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Steven Rostedt (Red Hat) authored
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.homeAcked-by:Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by:
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- 06 May, 2014 1 commit
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Christoph Lameter authored
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.orgAcked-by:
Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by:
Christoph Lameter <cl@linux.com> Signed-off-by:
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- 05 May, 2014 1 commit
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Frederic Weisbecker authored
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:
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- 02 May, 2014 1 commit
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Steven Rostedt (Red Hat) authored
Commit 4104d326 "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:
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- 30 Apr, 2014 1 commit
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Steven Rostedt (Red Hat) authored
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:
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- 29 Apr, 2014 1 commit
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Steven Rostedt (Red Hat) authored
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:
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- 24 Apr, 2014 2 commits
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Jiaxing Wang authored
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.cnSigned-off-by:
Jiaxing Wang <wangjiaxing@insigma.com.cn> Signed-off-by:
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Jiaxing Wang authored
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.cnSigned-off-by:
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- 21 Apr, 2014 8 commits
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Fabian Frederick authored
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.beSigned-off-by:
Fabian Frederick <fabf@skynet.be> Signed-off-by:
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Mathias Krause authored
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:
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Petr Mladek authored
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.czSigned-off-by:
Petr Mladek <pmladek@suse.cz> Signed-off-by:
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Steven Rostedt (Red Hat) authored
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 (Red Hat) authored
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 (Red Hat) authored
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 (Red Hat) authored
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 (Red Hat) authored
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:
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- 20 Apr, 2014 5 commits
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Linus Torvalds authored
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git://git.infradead.org/users/vkoul/slave-dmaLinus Torvalds authored
Pull slave-dmaengine fixes from Vinod Koul: "Back from long weekend here in India and now the time to send fixes for slave dmaengine. - Dan's fix of sirf xlate code - Jean's fix for timberland - edma fixes by Sekhar for SG handling and Yuan for changing init call" * 'fixes' of git://git.infradead.org/users/vkoul/slave-dma: dma: fix eDMA driver as a subsys_initcall dmaengine: sirf: off by one in of_dma_sirfsoc_xlate() platform: Fix timberdale dependencies dma: edma: fix incorrect SG list handling -
git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommuLinus Torvalds authored
Pull iommu fixes from Joerg Roedel: "Fixes for regressions: - fix wrong IOMMU enumeration causing some SCSI device drivers initialization failures - ARM-SMMU fixes for a panic condition and a wrong return value" * tag 'iommu-fixes-v3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: iommu/arm-smmu: fix panic in arm_smmu_alloc_init_pte iommu/arm-smmu: Return 0 on unmap failure iommu/vt-d: fix bug in matching PCI devices with DRHD/RMRR descriptors iommu/vt-d: Fix get_domain_for_dev() handling of upstream PCIe bridges iommu/vt-d: fix memory leakage caused by commit ea8ea460 -
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull perf tooling fixes from Ingo Molnar: "Three small tooling fixes" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf tools: Improve error reporting perf tools: Adjust symbols in VDSO perf kvm: Fix 'Min time' counting in report command
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Ingo Molnar authored
Merge tag 'perf-urgent-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf into perf/urgent Pull perf/urgent fixes from Jiri Olsa: User visible changes: * Adjust symbols in VDSO to properly resolve its function names (Vladimir Nikulichev) * Improve error reporting for record session failure (Adrien BAK) * Fix 'Min time' counting in report command (Alexander Yarygin) Signed-off-by:
Jiri Olsa <jolsa@redhat.com> Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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- 19 Apr, 2014 2 commits
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Adrien BAK authored
In the current version, when using perf record, if something goes wrong in tools/perf/builtin-record.c:375 session = perf_session__new(file, false, NULL); The error message: "Not enough memory for reading per file header" is issued. This error message seems to be outdated and is not very helpful. This patch proposes to replace this error message by "Perf session creation failed" I believe this issue has been brought to lkml: https://lkml.org/lkml/2014/2/24/458 although this patch only tackles a (small) part of the issue. Additionnaly, this patch improves error reporting in tools/perf/util/data.c open_file_write. Currently, if the call to open fails, the user is unaware of it. This patch logs the error, before returning the error code to the caller. Reported-by:
Will Deacon <will.deacon@arm.com> Signed-off-by:
Adrien BAK <adrien.bak@metascale.org> Link: http://lkml.kernel.org/r/1397786443.3093.4.camel@beast [ Reorganize the changelog into paragraphs ] [ Added empty line after fd declaration in open_file_write ] Signed-off-by:
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Vladimir Nikulichev authored
pert-report doesn't resolve function names in VDSO: $ perf report --stdio -g flat,0.0,15,callee --sort pid ... 8.76% 0x7fff6b1fe861 __gettimeofday ACE_OS::gettimeofday() ... In this case symbol values should be adjusted the same way as for executables, relocatable objects and prelinked libraries. After fix: $ perf report --stdio -g flat,0.0,15,callee --sort pid ... 8.76% __vdso_gettimeofday __gettimeofday ACE_OS::gettimeofday() Signed-off-by:Vladimir Nikulichev <nvs@tbricks.com> Tested-by:
Namhyung Kim <namhyung@kernel.org> Reviewed-by:
Adrian Hunter <adrian.hunter@intel.com> Link: http://lkml.kernel.org/r/969812.163009436-sendEmail@nvsSigned-off-by:
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