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author | Linus Torvalds <torvalds@linux-foundation.org> | 2015-06-22 22:19:21 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-06-22 22:19:21 (GMT) |
commit | c58267e9fa7b0345dd9006939254701e3622ca6a (patch) | |
tree | 9a96adabaa1c61ecbb9e5e8653d5085dad27ef07 /arch/x86/kernel/cpu/perf_event_intel_pt.c | |
parent | 1bf7067c6e173dc10411704db48338ed69c05565 (diff) | |
parent | a9a3cd900fbbcbf837d65653105e7bfc583ced09 (diff) | |
download | linux-c58267e9fa7b0345dd9006939254701e3622ca6a.tar.xz |
Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf updates from Ingo Molnar:
"Kernel side changes mostly consist of work on x86 PMU drivers:
- x86 Intel PT (hardware CPU tracer) improvements (Alexander
Shishkin)
- x86 Intel CQM (cache quality monitoring) improvements (Thomas
Gleixner)
- x86 Intel PEBSv3 support (Peter Zijlstra)
- x86 Intel PEBS interrupt batching support for lower overhead
sampling (Zheng Yan, Kan Liang)
- x86 PMU scheduler fixes and improvements (Peter Zijlstra)
There's too many tooling improvements to list them all - here are a
few select highlights:
'perf bench':
- Introduce new 'perf bench futex' benchmark: 'wake-parallel', to
measure parallel waker threads generating contention for kernel
locks (hb->lock). (Davidlohr Bueso)
'perf top', 'perf report':
- Allow disabling/enabling events dynamicaly in 'perf top':
a 'perf top' session can instantly become a 'perf report'
one, i.e. going from dynamic analysis to a static one,
returning to a dynamic one is possible, to toogle the
modes, just press 'f' to 'freeze/unfreeze' the sampling. (Arnaldo Carvalho de Melo)
- Make Ctrl-C stop processing on TUI, allowing interrupting the load of big
perf.data files (Namhyung Kim)
'perf probe': (Masami Hiramatsu)
- Support glob wildcards for function name
- Support $params special probe argument: Collect all function arguments
- Make --line checks validate C-style function name.
- Add --no-inlines option to avoid searching inline functions
- Greatly speed up 'perf probe --list' by caching debuginfo.
- Improve --filter support for 'perf probe', allowing using its arguments
on other commands, as --add, --del, etc.
'perf sched':
- Add option in 'perf sched' to merge like comms to lat output (Josef Bacik)
Plus tons of infrastructure work - in particular preparation for
upcoming threaded perf report support, but also lots of other work -
and fixes and other improvements. See (much) more details in the
shortlog and in the git log"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (305 commits)
perf tools: Configurable per thread proc map processing time out
perf tools: Add time out to force stop proc map processing
perf report: Fix sort__sym_cmp to also compare end of symbol
perf hists browser: React to unassigned hotkey pressing
perf top: Tell the user how to unfreeze events after pressing 'f'
perf hists browser: Honour the help line provided by builtin-{top,report}.c
perf hists browser: Do not exit when 'f' is pressed in 'report' mode
perf top: Replace CTRL+z with 'f' as hotkey for enable/disable events
perf annotate: Rename source_line_percent to source_line_samples
perf annotate: Display total number of samples with --show-total-period
perf tools: Ensure thread-stack is flushed
perf top: Allow disabling/enabling events dynamicly
perf evlist: Add toggle_enable() method
perf trace: Fix race condition at the end of started workloads
perf probe: Speed up perf probe --list by caching debuginfo
perf probe: Show usage even if the last event is skipped
perf tools: Move libtraceevent dynamic list to separated LDFLAGS variable
perf tools: Fix a problem when opening old perf.data with different byte order
perf tools: Ignore .config-detected in .gitignore
perf probe: Fix to return error if no probe is added
...
Diffstat (limited to 'arch/x86/kernel/cpu/perf_event_intel_pt.c')
-rw-r--r-- | arch/x86/kernel/cpu/perf_event_intel_pt.c | 38 |
1 files changed, 19 insertions, 19 deletions
diff --git a/arch/x86/kernel/cpu/perf_event_intel_pt.c b/arch/x86/kernel/cpu/perf_event_intel_pt.c index 123ff1b..159887c 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_pt.c +++ b/arch/x86/kernel/cpu/perf_event_intel_pt.c @@ -187,15 +187,6 @@ static bool pt_event_valid(struct perf_event *event) * These all are cpu affine and operate on a local PT */ -static bool pt_is_running(void) -{ - u64 ctl; - - rdmsrl(MSR_IA32_RTIT_CTL, ctl); - - return !!(ctl & RTIT_CTL_TRACEEN); -} - static void pt_config(struct perf_event *event) { u64 reg; @@ -609,7 +600,12 @@ static unsigned int pt_topa_next_entry(struct pt_buffer *buf, unsigned int pg) * @handle: Current output handle. * * Place INT and STOP marks to prevent overwriting old data that the consumer - * hasn't yet collected. + * hasn't yet collected and waking up the consumer after a certain fraction of + * the buffer has filled up. Only needed and sensible for non-snapshot counters. + * + * This obviously relies on buf::head to figure out buffer markers, so it has + * to be called after pt_buffer_reset_offsets() and before the hardware tracing + * is enabled. */ static int pt_buffer_reset_markers(struct pt_buffer *buf, struct perf_output_handle *handle) @@ -618,9 +614,6 @@ static int pt_buffer_reset_markers(struct pt_buffer *buf, unsigned long head = local64_read(&buf->head); unsigned long idx, npages, wakeup; - if (buf->snapshot) - return 0; - /* can't stop in the middle of an output region */ if (buf->output_off + handle->size + 1 < sizes(TOPA_ENTRY(buf->cur, buf->cur_idx)->size)) @@ -674,7 +667,7 @@ static void pt_buffer_setup_topa_index(struct pt_buffer *buf) struct topa *cur = buf->first, *prev = buf->last; struct topa_entry *te_cur = TOPA_ENTRY(cur, 0), *te_prev = TOPA_ENTRY(prev, prev->last - 1); - int pg = 0, idx = 0, ntopa = 0; + int pg = 0, idx = 0; while (pg < buf->nr_pages) { int tidx; @@ -689,9 +682,9 @@ static void pt_buffer_setup_topa_index(struct pt_buffer *buf) /* advance to next topa table */ idx = 0; cur = list_entry(cur->list.next, struct topa, list); - ntopa++; - } else + } else { idx++; + } te_cur = TOPA_ENTRY(cur, idx); } @@ -703,7 +696,14 @@ static void pt_buffer_setup_topa_index(struct pt_buffer *buf) * @head: Write pointer (aux_head) from AUX buffer. * * Find the ToPA table and entry corresponding to given @head and set buffer's - * "current" pointers accordingly. + * "current" pointers accordingly. This is done after we have obtained the + * current aux_head position from a successful call to perf_aux_output_begin() + * to make sure the hardware is writing to the right place. + * + * This function modifies buf::{cur,cur_idx,output_off} that will be programmed + * into PT msrs when the tracing is enabled and buf::head and buf::data_size, + * which are used to determine INT and STOP markers' locations by a subsequent + * call to pt_buffer_reset_markers(). */ static void pt_buffer_reset_offsets(struct pt_buffer *buf, unsigned long head) { @@ -901,6 +901,7 @@ void intel_pt_interrupt(void) } pt_buffer_reset_offsets(buf, pt->handle.head); + /* snapshot counters don't use PMI, so it's safe */ ret = pt_buffer_reset_markers(buf, &pt->handle); if (ret) { perf_aux_output_end(&pt->handle, 0, true); @@ -923,7 +924,7 @@ static void pt_event_start(struct perf_event *event, int mode) struct pt *pt = this_cpu_ptr(&pt_ctx); struct pt_buffer *buf = perf_get_aux(&pt->handle); - if (pt_is_running() || !buf || pt_buffer_is_full(buf, pt)) { + if (!buf || pt_buffer_is_full(buf, pt)) { event->hw.state = PERF_HES_STOPPED; return; } @@ -954,7 +955,6 @@ static void pt_event_stop(struct perf_event *event, int mode) event->hw.state = PERF_HES_STOPPED; if (mode & PERF_EF_UPDATE) { - struct pt *pt = this_cpu_ptr(&pt_ctx); struct pt_buffer *buf = perf_get_aux(&pt->handle); if (!buf) |