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().
Signed-off-by: Johannes Thumshirn <johannes.thumsh...@wdc.com> --- kernel/trace/blktrace.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index 5db0c1a4ef5e..d06519957c25 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -104,13 +104,14 @@ 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); @@ -125,7 +126,7 @@ 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()); @@ -254,6 +255,7 @@ 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; @@ -276,14 +278,14 @@ 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); @@ -304,7 +306,7 @@ 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); -- 2.51.0