* [PATCH 0/3] perf intel-pt: Intel PT fixes
@ 2019-05-10 12:41 Adrian Hunter
2019-05-10 12:41 ` [PATCH 1/3] perf intel-pt: Fix instructions sampling rate Adrian Hunter
` (3 more replies)
0 siblings, 4 replies; 8+ messages in thread
From: Adrian Hunter @ 2019-05-10 12:41 UTC (permalink / raw)
To: Arnaldo Carvalho de Melo; +Cc: Jiri Olsa, linux-kernel
Hi
Here are 3 non-urgent fixes for Intel PT.
Adrian Hunter (3):
perf intel-pt: Fix instructions sampling rate
perf intel-pt: Fix improved sample timestamp
perf intel-pt: Fix sample timestamp wrt non-taken branches
.../perf/util/intel-pt-decoder/intel-pt-decoder.c | 31 +++++++++++++++++-----
1 file changed, 24 insertions(+), 7 deletions(-)
Regards
Adrian
^ permalink raw reply [flat|nested] 8+ messages in thread* [PATCH 1/3] perf intel-pt: Fix instructions sampling rate 2019-05-10 12:41 [PATCH 0/3] perf intel-pt: Intel PT fixes Adrian Hunter @ 2019-05-10 12:41 ` Adrian Hunter 2019-05-18 9:32 ` [tip:perf/core] " tip-bot for Adrian Hunter 2019-05-10 12:41 ` [PATCH 2/3] perf intel-pt: Fix improved sample timestamp Adrian Hunter ` (2 subsequent siblings) 3 siblings, 1 reply; 8+ messages in thread From: Adrian Hunter @ 2019-05-10 12:41 UTC (permalink / raw) To: Arnaldo Carvalho de Melo; +Cc: Jiri Olsa, linux-kernel The timestamp used to determine if an instruction sample is made, is an estimate based on the number of instructions since the last known timestamp. A consequence is that it might go backwards, which results in extra samples. Change it so that a sample is only made when the timestamp goes forwards. Note this does not affect a sampling period of 0 or sampling periods specified as a count of instructions. Example: Before: $ perf script --itrace=i10us ls 13812 [003] 2167315.222583: 3270 instructions:u: 7fac71e2e494 __GI___tunables_init+0xf4 (/lib/x86_64-linux-gnu/ld-2.28.so) ls 13812 [003] 2167315.222667: 30902 instructions:u: 7fac71e2da0f _dl_cache_libcmp+0x2f (/lib/x86_64-linux-gnu/ld-2.28.so) ls 13812 [003] 2167315.222667: 10 instructions:u: 7fac71e2d9ff _dl_cache_libcmp+0x1f (/lib/x86_64-linux-gnu/ld-2.28.so) ls 13812 [003] 2167315.222667: 8 instructions:u: 7fac71e2d9ea _dl_cache_libcmp+0xa (/lib/x86_64-linux-gnu/ld-2.28.so) ls 13812 [003] 2167315.222667: 14 instructions:u: 7fac71e2d9ea _dl_cache_libcmp+0xa (/lib/x86_64-linux-gnu/ld-2.28.so) ls 13812 [003] 2167315.222667: 6 instructions:u: 7fac71e2d9ff _dl_cache_libcmp+0x1f (/lib/x86_64-linux-gnu/ld-2.28.so) ls 13812 [003] 2167315.222667: 14 instructions:u: 7fac71e2d9ff _dl_cache_libcmp+0x1f (/lib/x86_64-linux-gnu/ld-2.28.so) ls 13812 [003] 2167315.222667: 4 instructions:u: 7fac71e2dab2 _dl_cache_libcmp+0xd2 (/lib/x86_64-linux-gnu/ld-2.28.so) ls 13812 [003] 2167315.222728: 16423 instructions:u: 7fac71e2477a _dl_map_object_deps+0x1ba (/lib/x86_64-linux-gnu/ld-2.28.so) ls 13812 [003] 2167315.222734: 12731 instructions:u: 7fac71e27938 _dl_name_match_p+0x68 (/lib/x86_64-linux-gnu/ld-2.28.so) ... After: $ perf script --itrace=i10us ls 13812 [003] 2167315.222583: 3270 instructions:u: 7fac71e2e494 __GI___tunables_init+0xf4 (/lib/x86_64-linux-gnu/ld-2.28.so) ls 13812 [003] 2167315.222667: 30902 instructions:u: 7fac71e2da0f _dl_cache_libcmp+0x2f (/lib/x86_64-linux-gnu/ld-2.28.so) ls 13812 [003] 2167315.222728: 16479 instructions:u: 7fac71e2477a _dl_map_object_deps+0x1ba (/lib/x86_64-linux-gnu/ld-2.28.so) ... Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Fixes: f4aa081949e7b ("perf tools: Add Intel PT decoder") Cc: stable@vger.kernel.org --- tools/perf/util/intel-pt-decoder/intel-pt-decoder.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c index 872fab163585..26dbf11e071a 100644 --- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c +++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c @@ -888,16 +888,20 @@ static uint64_t intel_pt_next_period(struct intel_pt_decoder *decoder) timestamp = decoder->timestamp + decoder->timestamp_insn_cnt; masked_timestamp = timestamp & decoder->period_mask; if (decoder->continuous_period) { - if (masked_timestamp != decoder->last_masked_timestamp) + if (masked_timestamp > decoder->last_masked_timestamp) return 1; } else { timestamp += 1; masked_timestamp = timestamp & decoder->period_mask; - if (masked_timestamp != decoder->last_masked_timestamp) { + if (masked_timestamp > decoder->last_masked_timestamp) { decoder->last_masked_timestamp = masked_timestamp; decoder->continuous_period = true; } } + + if (masked_timestamp < decoder->last_masked_timestamp) + return decoder->period_ticks; + return decoder->period_ticks - (timestamp - masked_timestamp); } @@ -926,7 +930,10 @@ static void intel_pt_sample_insn(struct intel_pt_decoder *decoder) case INTEL_PT_PERIOD_TICKS: timestamp = decoder->timestamp + decoder->timestamp_insn_cnt; masked_timestamp = timestamp & decoder->period_mask; - decoder->last_masked_timestamp = masked_timestamp; + if (masked_timestamp > decoder->last_masked_timestamp) + decoder->last_masked_timestamp = masked_timestamp; + else + decoder->last_masked_timestamp += decoder->period_ticks; break; case INTEL_PT_PERIOD_NONE: case INTEL_PT_PERIOD_MTC: -- 2.17.1 ^ permalink raw reply related [flat|nested] 8+ messages in thread
* [tip:perf/core] perf intel-pt: Fix instructions sampling rate 2019-05-10 12:41 ` [PATCH 1/3] perf intel-pt: Fix instructions sampling rate Adrian Hunter @ 2019-05-18 9:32 ` tip-bot for Adrian Hunter 0 siblings, 0 replies; 8+ messages in thread From: tip-bot for Adrian Hunter @ 2019-05-18 9:32 UTC (permalink / raw) To: linux-tip-commits Cc: acme, adrian.hunter, hpa, tglx, mingo, linux-kernel, jolsa Commit-ID: 7ba8fa20e26eb3c0c04d747f7fd2223694eac4d5 Gitweb: https://git.kernel.org/tip/7ba8fa20e26eb3c0c04d747f7fd2223694eac4d5 Author: Adrian Hunter <adrian.hunter@intel.com> AuthorDate: Fri, 10 May 2019 15:41:41 +0300 Committer: Arnaldo Carvalho de Melo <acme@redhat.com> CommitDate: Thu, 16 May 2019 14:17:23 -0300 perf intel-pt: Fix instructions sampling rate The timestamp used to determine if an instruction sample is made, is an estimate based on the number of instructions since the last known timestamp. A consequence is that it might go backwards, which results in extra samples. Change it so that a sample is only made when the timestamp goes forwards. Note this does not affect a sampling period of 0 or sampling periods specified as a count of instructions. Example: Before: $ perf script --itrace=i10us ls 13812 [003] 2167315.222583: 3270 instructions:u: 7fac71e2e494 __GI___tunables_init+0xf4 (/lib/x86_64-linux-gnu/ld-2.28.so) ls 13812 [003] 2167315.222667: 30902 instructions:u: 7fac71e2da0f _dl_cache_libcmp+0x2f (/lib/x86_64-linux-gnu/ld-2.28.so) ls 13812 [003] 2167315.222667: 10 instructions:u: 7fac71e2d9ff _dl_cache_libcmp+0x1f (/lib/x86_64-linux-gnu/ld-2.28.so) ls 13812 [003] 2167315.222667: 8 instructions:u: 7fac71e2d9ea _dl_cache_libcmp+0xa (/lib/x86_64-linux-gnu/ld-2.28.so) ls 13812 [003] 2167315.222667: 14 instructions:u: 7fac71e2d9ea _dl_cache_libcmp+0xa (/lib/x86_64-linux-gnu/ld-2.28.so) ls 13812 [003] 2167315.222667: 6 instructions:u: 7fac71e2d9ff _dl_cache_libcmp+0x1f (/lib/x86_64-linux-gnu/ld-2.28.so) ls 13812 [003] 2167315.222667: 14 instructions:u: 7fac71e2d9ff _dl_cache_libcmp+0x1f (/lib/x86_64-linux-gnu/ld-2.28.so) ls 13812 [003] 2167315.222667: 4 instructions:u: 7fac71e2dab2 _dl_cache_libcmp+0xd2 (/lib/x86_64-linux-gnu/ld-2.28.so) ls 13812 [003] 2167315.222728: 16423 instructions:u: 7fac71e2477a _dl_map_object_deps+0x1ba (/lib/x86_64-linux-gnu/ld-2.28.so) ls 13812 [003] 2167315.222734: 12731 instructions:u: 7fac71e27938 _dl_name_match_p+0x68 (/lib/x86_64-linux-gnu/ld-2.28.so) ... After: $ perf script --itrace=i10us ls 13812 [003] 2167315.222583: 3270 instructions:u: 7fac71e2e494 __GI___tunables_init+0xf4 (/lib/x86_64-linux-gnu/ld-2.28.so) ls 13812 [003] 2167315.222667: 30902 instructions:u: 7fac71e2da0f _dl_cache_libcmp+0x2f (/lib/x86_64-linux-gnu/ld-2.28.so) ls 13812 [003] 2167315.222728: 16479 instructions:u: 7fac71e2477a _dl_map_object_deps+0x1ba (/lib/x86_64-linux-gnu/ld-2.28.so) ... Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: stable@vger.kernel.org Fixes: f4aa081949e7b ("perf tools: Add Intel PT decoder") Link: http://lkml.kernel.org/r/20190510124143.27054-2-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> --- tools/perf/util/intel-pt-decoder/intel-pt-decoder.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c index 872fab163585..26dbf11e071a 100644 --- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c +++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c @@ -888,16 +888,20 @@ static uint64_t intel_pt_next_period(struct intel_pt_decoder *decoder) timestamp = decoder->timestamp + decoder->timestamp_insn_cnt; masked_timestamp = timestamp & decoder->period_mask; if (decoder->continuous_period) { - if (masked_timestamp != decoder->last_masked_timestamp) + if (masked_timestamp > decoder->last_masked_timestamp) return 1; } else { timestamp += 1; masked_timestamp = timestamp & decoder->period_mask; - if (masked_timestamp != decoder->last_masked_timestamp) { + if (masked_timestamp > decoder->last_masked_timestamp) { decoder->last_masked_timestamp = masked_timestamp; decoder->continuous_period = true; } } + + if (masked_timestamp < decoder->last_masked_timestamp) + return decoder->period_ticks; + return decoder->period_ticks - (timestamp - masked_timestamp); } @@ -926,7 +930,10 @@ static void intel_pt_sample_insn(struct intel_pt_decoder *decoder) case INTEL_PT_PERIOD_TICKS: timestamp = decoder->timestamp + decoder->timestamp_insn_cnt; masked_timestamp = timestamp & decoder->period_mask; - decoder->last_masked_timestamp = masked_timestamp; + if (masked_timestamp > decoder->last_masked_timestamp) + decoder->last_masked_timestamp = masked_timestamp; + else + decoder->last_masked_timestamp += decoder->period_ticks; break; case INTEL_PT_PERIOD_NONE: case INTEL_PT_PERIOD_MTC: ^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH 2/3] perf intel-pt: Fix improved sample timestamp 2019-05-10 12:41 [PATCH 0/3] perf intel-pt: Intel PT fixes Adrian Hunter 2019-05-10 12:41 ` [PATCH 1/3] perf intel-pt: Fix instructions sampling rate Adrian Hunter @ 2019-05-10 12:41 ` Adrian Hunter 2019-05-18 9:33 ` [tip:perf/core] " tip-bot for Adrian Hunter 2019-05-10 12:41 ` [PATCH 3/3] perf intel-pt: Fix sample timestamp wrt non-taken branches Adrian Hunter 2019-05-15 19:30 ` [PATCH 0/3] perf intel-pt: Intel PT fixes Arnaldo Carvalho de Melo 3 siblings, 1 reply; 8+ messages in thread From: Adrian Hunter @ 2019-05-10 12:41 UTC (permalink / raw) To: Arnaldo Carvalho de Melo; +Cc: Jiri Olsa, linux-kernel The decoder uses its current timestamp in samples. Usually that is a timestamp that has already passed, but in some cases it is a timestamp for a branch that the decoder is walking towards, and consequently hasn't reached. The intel_pt_sample_time() function decides which is which, but was not handling TNT packets exactly correctly. In the case of TNT, the timestamp applies to the first branch, so the decoder must first walk to that branch. That means intel_pt_sample_time() should return true for TNT, and this patch makes that change. However, if the first branch is a non-taken branch (i.e. a 'N'), then intel_pt_sample_time() needs to return false for subsequent taken branches in the same TNT packet. To handle that, introduce a new state INTEL_PT_STATE_TNT_CONT to distinguish the cases. Note that commit 3f04d98e972b5 ("perf intel-pt: Improve sample timestamp") was also a stable fix and appears, for example, in v4.4 stable tree as commit a4ebb58fd124 ("perf intel-pt: Improve sample timestamp"). Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Fixes: 3f04d98e972b5 ("perf intel-pt: Improve sample timestamp") Cc: stable@vger.kernel.org # v4.4+ --- tools/perf/util/intel-pt-decoder/intel-pt-decoder.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c index 26dbf11e071a..9cbd587489bf 100644 --- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c +++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c @@ -58,6 +58,7 @@ enum intel_pt_pkt_state { INTEL_PT_STATE_NO_IP, INTEL_PT_STATE_ERR_RESYNC, INTEL_PT_STATE_IN_SYNC, + INTEL_PT_STATE_TNT_CONT, INTEL_PT_STATE_TNT, INTEL_PT_STATE_TIP, INTEL_PT_STATE_TIP_PGD, @@ -72,8 +73,9 @@ static inline bool intel_pt_sample_time(enum intel_pt_pkt_state pkt_state) case INTEL_PT_STATE_NO_IP: case INTEL_PT_STATE_ERR_RESYNC: case INTEL_PT_STATE_IN_SYNC: - case INTEL_PT_STATE_TNT: + case INTEL_PT_STATE_TNT_CONT: return true; + case INTEL_PT_STATE_TNT: case INTEL_PT_STATE_TIP: case INTEL_PT_STATE_TIP_PGD: case INTEL_PT_STATE_FUP: @@ -1261,7 +1263,9 @@ static int intel_pt_walk_tnt(struct intel_pt_decoder *decoder) return -ENOENT; } decoder->tnt.count -= 1; - if (!decoder->tnt.count) + if (decoder->tnt.count) + decoder->pkt_state = INTEL_PT_STATE_TNT_CONT; + else decoder->pkt_state = INTEL_PT_STATE_IN_SYNC; decoder->tnt.payload <<= 1; decoder->state.from_ip = decoder->ip; @@ -1292,7 +1296,9 @@ static int intel_pt_walk_tnt(struct intel_pt_decoder *decoder) if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) { decoder->tnt.count -= 1; - if (!decoder->tnt.count) + if (decoder->tnt.count) + decoder->pkt_state = INTEL_PT_STATE_TNT_CONT; + else decoder->pkt_state = INTEL_PT_STATE_IN_SYNC; if (decoder->tnt.payload & BIT63) { decoder->tnt.payload <<= 1; @@ -2372,6 +2378,7 @@ const struct intel_pt_state *intel_pt_decode(struct intel_pt_decoder *decoder) err = intel_pt_walk_trace(decoder); break; case INTEL_PT_STATE_TNT: + case INTEL_PT_STATE_TNT_CONT: err = intel_pt_walk_tnt(decoder); if (err == -EAGAIN) err = intel_pt_walk_trace(decoder); -- 2.17.1 ^ permalink raw reply related [flat|nested] 8+ messages in thread
* [tip:perf/core] perf intel-pt: Fix improved sample timestamp 2019-05-10 12:41 ` [PATCH 2/3] perf intel-pt: Fix improved sample timestamp Adrian Hunter @ 2019-05-18 9:33 ` tip-bot for Adrian Hunter 0 siblings, 0 replies; 8+ messages in thread From: tip-bot for Adrian Hunter @ 2019-05-18 9:33 UTC (permalink / raw) To: linux-tip-commits Cc: linux-kernel, jolsa, tglx, hpa, adrian.hunter, acme, mingo Commit-ID: 61b6e08dc8e3ea80b7485c9b3f875ddd45c8466b Gitweb: https://git.kernel.org/tip/61b6e08dc8e3ea80b7485c9b3f875ddd45c8466b Author: Adrian Hunter <adrian.hunter@intel.com> AuthorDate: Fri, 10 May 2019 15:41:42 +0300 Committer: Arnaldo Carvalho de Melo <acme@redhat.com> CommitDate: Thu, 16 May 2019 14:17:23 -0300 perf intel-pt: Fix improved sample timestamp The decoder uses its current timestamp in samples. Usually that is a timestamp that has already passed, but in some cases it is a timestamp for a branch that the decoder is walking towards, and consequently hasn't reached. The intel_pt_sample_time() function decides which is which, but was not handling TNT packets exactly correctly. In the case of TNT, the timestamp applies to the first branch, so the decoder must first walk to that branch. That means intel_pt_sample_time() should return true for TNT, and this patch makes that change. However, if the first branch is a non-taken branch (i.e. a 'N'), then intel_pt_sample_time() needs to return false for subsequent taken branches in the same TNT packet. To handle that, introduce a new state INTEL_PT_STATE_TNT_CONT to distinguish the cases. Note that commit 3f04d98e972b5 ("perf intel-pt: Improve sample timestamp") was also a stable fix and appears, for example, in v4.4 stable tree as commit a4ebb58fd124 ("perf intel-pt: Improve sample timestamp"). Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: stable@vger.kernel.org # v4.4+ Fixes: 3f04d98e972b5 ("perf intel-pt: Improve sample timestamp") Link: http://lkml.kernel.org/r/20190510124143.27054-3-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> --- tools/perf/util/intel-pt-decoder/intel-pt-decoder.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c index 26dbf11e071a..9cbd587489bf 100644 --- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c +++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c @@ -58,6 +58,7 @@ enum intel_pt_pkt_state { INTEL_PT_STATE_NO_IP, INTEL_PT_STATE_ERR_RESYNC, INTEL_PT_STATE_IN_SYNC, + INTEL_PT_STATE_TNT_CONT, INTEL_PT_STATE_TNT, INTEL_PT_STATE_TIP, INTEL_PT_STATE_TIP_PGD, @@ -72,8 +73,9 @@ static inline bool intel_pt_sample_time(enum intel_pt_pkt_state pkt_state) case INTEL_PT_STATE_NO_IP: case INTEL_PT_STATE_ERR_RESYNC: case INTEL_PT_STATE_IN_SYNC: - case INTEL_PT_STATE_TNT: + case INTEL_PT_STATE_TNT_CONT: return true; + case INTEL_PT_STATE_TNT: case INTEL_PT_STATE_TIP: case INTEL_PT_STATE_TIP_PGD: case INTEL_PT_STATE_FUP: @@ -1261,7 +1263,9 @@ static int intel_pt_walk_tnt(struct intel_pt_decoder *decoder) return -ENOENT; } decoder->tnt.count -= 1; - if (!decoder->tnt.count) + if (decoder->tnt.count) + decoder->pkt_state = INTEL_PT_STATE_TNT_CONT; + else decoder->pkt_state = INTEL_PT_STATE_IN_SYNC; decoder->tnt.payload <<= 1; decoder->state.from_ip = decoder->ip; @@ -1292,7 +1296,9 @@ static int intel_pt_walk_tnt(struct intel_pt_decoder *decoder) if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) { decoder->tnt.count -= 1; - if (!decoder->tnt.count) + if (decoder->tnt.count) + decoder->pkt_state = INTEL_PT_STATE_TNT_CONT; + else decoder->pkt_state = INTEL_PT_STATE_IN_SYNC; if (decoder->tnt.payload & BIT63) { decoder->tnt.payload <<= 1; @@ -2372,6 +2378,7 @@ const struct intel_pt_state *intel_pt_decode(struct intel_pt_decoder *decoder) err = intel_pt_walk_trace(decoder); break; case INTEL_PT_STATE_TNT: + case INTEL_PT_STATE_TNT_CONT: err = intel_pt_walk_tnt(decoder); if (err == -EAGAIN) err = intel_pt_walk_trace(decoder); ^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH 3/3] perf intel-pt: Fix sample timestamp wrt non-taken branches 2019-05-10 12:41 [PATCH 0/3] perf intel-pt: Intel PT fixes Adrian Hunter 2019-05-10 12:41 ` [PATCH 1/3] perf intel-pt: Fix instructions sampling rate Adrian Hunter 2019-05-10 12:41 ` [PATCH 2/3] perf intel-pt: Fix improved sample timestamp Adrian Hunter @ 2019-05-10 12:41 ` Adrian Hunter 2019-05-18 9:34 ` [tip:perf/core] " tip-bot for Adrian Hunter 2019-05-15 19:30 ` [PATCH 0/3] perf intel-pt: Intel PT fixes Arnaldo Carvalho de Melo 3 siblings, 1 reply; 8+ messages in thread From: Adrian Hunter @ 2019-05-10 12:41 UTC (permalink / raw) To: Arnaldo Carvalho de Melo; +Cc: Jiri Olsa, linux-kernel The sample timestamp is updated to ensure that the timestamp represents the time of the sample and not a branch that the decoder is still walking towards. The sample timestamp is updated when the decoder returns, but the decoder does not return for non-taken branches. Update the sample timestamp then also. Note that commit 3f04d98e972b5 ("perf intel-pt: Improve sample timestamp") was also a stable fix and appears, for example, in v4.4 stable tree as commit a4ebb58fd124 ("perf intel-pt: Improve sample timestamp"). Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Fixes: 3f04d98e972b ("perf intel-pt: Improve sample timestamp") Cc: stable@vger.kernel.org # v4.4+ --- tools/perf/util/intel-pt-decoder/intel-pt-decoder.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c index 9cbd587489bf..f4c3c84b090f 100644 --- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c +++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c @@ -1318,8 +1318,11 @@ static int intel_pt_walk_tnt(struct intel_pt_decoder *decoder) return 0; } decoder->ip += intel_pt_insn.length; - if (!decoder->tnt.count) + if (!decoder->tnt.count) { + decoder->sample_timestamp = decoder->timestamp; + decoder->sample_insn_cnt = decoder->timestamp_insn_cnt; return -EAGAIN; + } decoder->tnt.payload <<= 1; continue; } -- 2.17.1 ^ permalink raw reply related [flat|nested] 8+ messages in thread
* [tip:perf/core] perf intel-pt: Fix sample timestamp wrt non-taken branches 2019-05-10 12:41 ` [PATCH 3/3] perf intel-pt: Fix sample timestamp wrt non-taken branches Adrian Hunter @ 2019-05-18 9:34 ` tip-bot for Adrian Hunter 0 siblings, 0 replies; 8+ messages in thread From: tip-bot for Adrian Hunter @ 2019-05-18 9:34 UTC (permalink / raw) To: linux-tip-commits Cc: jolsa, adrian.hunter, acme, mingo, linux-kernel, hpa, tglx Commit-ID: 1b6599a9d8e6c9f7e9b0476012383b1777f7fc93 Gitweb: https://git.kernel.org/tip/1b6599a9d8e6c9f7e9b0476012383b1777f7fc93 Author: Adrian Hunter <adrian.hunter@intel.com> AuthorDate: Fri, 10 May 2019 15:41:43 +0300 Committer: Arnaldo Carvalho de Melo <acme@redhat.com> CommitDate: Thu, 16 May 2019 14:17:24 -0300 perf intel-pt: Fix sample timestamp wrt non-taken branches The sample timestamp is updated to ensure that the timestamp represents the time of the sample and not a branch that the decoder is still walking towards. The sample timestamp is updated when the decoder returns, but the decoder does not return for non-taken branches. Update the sample timestamp then also. Note that commit 3f04d98e972b5 ("perf intel-pt: Improve sample timestamp") was also a stable fix and appears, for example, in v4.4 stable tree as commit a4ebb58fd124 ("perf intel-pt: Improve sample timestamp"). Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: stable@vger.kernel.org # v4.4+ Fixes: 3f04d98e972b ("perf intel-pt: Improve sample timestamp") Link: http://lkml.kernel.org/r/20190510124143.27054-4-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> --- tools/perf/util/intel-pt-decoder/intel-pt-decoder.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c index 9cbd587489bf..f4c3c84b090f 100644 --- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c +++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c @@ -1318,8 +1318,11 @@ static int intel_pt_walk_tnt(struct intel_pt_decoder *decoder) return 0; } decoder->ip += intel_pt_insn.length; - if (!decoder->tnt.count) + if (!decoder->tnt.count) { + decoder->sample_timestamp = decoder->timestamp; + decoder->sample_insn_cnt = decoder->timestamp_insn_cnt; return -EAGAIN; + } decoder->tnt.payload <<= 1; continue; } ^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH 0/3] perf intel-pt: Intel PT fixes 2019-05-10 12:41 [PATCH 0/3] perf intel-pt: Intel PT fixes Adrian Hunter ` (2 preceding siblings ...) 2019-05-10 12:41 ` [PATCH 3/3] perf intel-pt: Fix sample timestamp wrt non-taken branches Adrian Hunter @ 2019-05-15 19:30 ` Arnaldo Carvalho de Melo 3 siblings, 0 replies; 8+ messages in thread From: Arnaldo Carvalho de Melo @ 2019-05-15 19:30 UTC (permalink / raw) To: Adrian Hunter; +Cc: Jiri Olsa, linux-kernel Em Fri, May 10, 2019 at 03:41:40PM +0300, Adrian Hunter escreveu: > Hi > > Here are 3 non-urgent fixes for Intel PT. Thanks, applied. - Arnaldo > > Adrian Hunter (3): > perf intel-pt: Fix instructions sampling rate > perf intel-pt: Fix improved sample timestamp > perf intel-pt: Fix sample timestamp wrt non-taken branches > > .../perf/util/intel-pt-decoder/intel-pt-decoder.c | 31 +++++++++++++++++----- > 1 file changed, 24 insertions(+), 7 deletions(-) > > > Regards > Adrian -- - Arnaldo ^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2019-05-18 9:34 UTC | newest] Thread overview: 8+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2019-05-10 12:41 [PATCH 0/3] perf intel-pt: Intel PT fixes Adrian Hunter 2019-05-10 12:41 ` [PATCH 1/3] perf intel-pt: Fix instructions sampling rate Adrian Hunter 2019-05-18 9:32 ` [tip:perf/core] " tip-bot for Adrian Hunter 2019-05-10 12:41 ` [PATCH 2/3] perf intel-pt: Fix improved sample timestamp Adrian Hunter 2019-05-18 9:33 ` [tip:perf/core] " tip-bot for Adrian Hunter 2019-05-10 12:41 ` [PATCH 3/3] perf intel-pt: Fix sample timestamp wrt non-taken branches Adrian Hunter 2019-05-18 9:34 ` [tip:perf/core] " tip-bot for Adrian Hunter 2019-05-15 19:30 ` [PATCH 0/3] perf intel-pt: Intel PT fixes Arnaldo Carvalho de Melo
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