Re: [PATCH v4 07/11] perf auxtrace: Remove auxtrace_mmap__read_snapshot_head()
From: Adrian Hunter <adrian.hunter@intel.com>
Date: 2021-07-12 14:32:07
Also in:
linux-perf-users, lkml
On 11/07/21 1:41 pm, Leo Yan wrote:
quoted hunk ↗ jump to hunk
Since the function auxtrace_mmap__read_snapshot_head() is exactly same with auxtrace_mmap__read_head(), whether the session is in snapshot mode or not, it's unified to use function auxtrace_mmap__read_head() for reading AUX buffer head. And the function auxtrace_mmap__read_snapshot_head() is unused so this patch removes it. Signed-off-by: Leo Yan <redacted> --- tools/perf/util/auxtrace.c | 5 ++--- tools/perf/util/auxtrace.h | 10 ---------- 2 files changed, 2 insertions(+), 13 deletions(-)diff --git a/tools/perf/util/auxtrace.c b/tools/perf/util/auxtrace.c index cb19669d2a5b..7958e17229ea 100644 --- a/tools/perf/util/auxtrace.c +++ b/tools/perf/util/auxtrace.c@@ -1686,13 +1686,12 @@ static int __auxtrace_mmap__read(struct mmap *map, union perf_event ev; void *data1, *data2; + head = auxtrace_mmap__read_head(mm); + if (snapshot) { - head = auxtrace_mmap__read_snapshot_head(mm); if (auxtrace_record__find_snapshot(itr, mm->idx, mm, data, &head, &old))
That leaves a nested 'if' which is not kernel style i.e. could be if (snapshot && auxtrace_record__find_snapshot(itr, mm->idx, mm, data, &head, &old))
quoted hunk ↗ jump to hunk
return -1; - } else { - head = auxtrace_mmap__read_head(mm); } if (old == head)diff --git a/tools/perf/util/auxtrace.h b/tools/perf/util/auxtrace.h index 4f9176368134..d68a5e80b217 100644 --- a/tools/perf/util/auxtrace.h +++ b/tools/perf/util/auxtrace.h@@ -440,16 +440,6 @@ struct auxtrace_cache; #ifdef HAVE_AUXTRACE_SUPPORT -static inline u64 auxtrace_mmap__read_snapshot_head(struct auxtrace_mmap *mm) -{ - struct perf_event_mmap_page *pc = mm->userpg; - u64 head = READ_ONCE(pc->aux_head); - - /* Ensure all reads are done after we read the head */ - smp_rmb(); - return head; -} - static inline u64 auxtrace_mmap__read_head(struct auxtrace_mmap *mm) { struct perf_event_mmap_page *pc = mm->userpg;
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