diff options
| author | Johannes Thumshirn <johannes.thumshirn@wdc.com> | 2025-10-22 13:41:00 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2025-10-22 11:14:05 -0600 |
| commit | a65988a0ad047dbdb8a1eb6f07540b980858b522 (patch) | |
| tree | bb3b0e6688350ce468345973235e0bec6177a7b6 /kernel | |
| parent | 5c5028ee594ce5f907ca6ad1c32cca6a15098464 (diff) | |
blktrace: only calculate trace length once
De-duplicate the calculation of the trace length instead of doing the
calculation twice, once for calling trace_buffer_lock_reserve() and once
for calling relay_reserve().
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/blktrace.c | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index 6941145b5058..bc4b885f2cec 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -76,13 +76,14 @@ static void trace_note(struct blk_trace *bt, pid_t pid, int action, int cpu = smp_processor_id(); bool blk_tracer = blk_tracer_enabled; ssize_t cgid_len = cgid ? sizeof(cgid) : 0; + size_t trace_len; + trace_len = sizeof(*t) + cgid_len + len; if (blk_tracer) { buffer = blk_tr->array_buffer.buffer; trace_ctx = tracing_gen_ctx_flags(0); event = trace_buffer_lock_reserve(buffer, TRACE_BLK, - sizeof(*t) + len + cgid_len, - trace_ctx); + trace_len, trace_ctx); if (!event) return; t = ring_buffer_event_data(event); @@ -92,7 +93,7 @@ static void trace_note(struct blk_trace *bt, pid_t pid, int action, if (!bt->rchan) return; - t = relay_reserve(bt->rchan, sizeof(*t) + len + cgid_len); + t = relay_reserve(bt->rchan, trace_len); if (t) { t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION; t->time = ktime_to_ns(ktime_get()); @@ -228,6 +229,7 @@ static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes, bool blk_tracer = blk_tracer_enabled; ssize_t cgid_len = cgid ? sizeof(cgid) : 0; const enum req_op op = opf & REQ_OP_MASK; + size_t trace_len; if (unlikely(bt->trace_state != Blktrace_running && !blk_tracer)) return; @@ -250,14 +252,14 @@ static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes, return; cpu = raw_smp_processor_id(); + trace_len = sizeof(*t) + pdu_len + cgid_len; if (blk_tracer) { tracing_record_cmdline(current); buffer = blk_tr->array_buffer.buffer; trace_ctx = tracing_gen_ctx_flags(0); event = trace_buffer_lock_reserve(buffer, TRACE_BLK, - sizeof(*t) + pdu_len + cgid_len, - trace_ctx); + trace_len, trace_ctx); if (!event) return; t = ring_buffer_event_data(event); @@ -273,7 +275,7 @@ static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes, * from coming in and stepping on our toes. */ local_irq_save(flags); - t = relay_reserve(bt->rchan, sizeof(*t) + pdu_len + cgid_len); + t = relay_reserve(bt->rchan, trace_len); if (t) { sequence = per_cpu_ptr(bt->sequence, cpu); |