[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20161123201105.GA3092@twins.programming.kicks-ass.net>
Date: Wed, 23 Nov 2016 21:11:05 +0100
From: Peter Zijlstra <peterz@...radead.org>
To: kan.liang@...el.com
Cc: mingo@...hat.com, acme@...nel.org, linux-kernel@...r.kernel.org,
alexander.shishkin@...ux.intel.com, tglx@...utronix.de,
namhyung@...nel.org, jolsa@...nel.org, adrian.hunter@...el.com,
wangnan0@...wei.com, mark.rutland@....com, andi@...stfloor.org
Subject: Re: [PATCH 01/14] perf/x86: Introduce PERF_RECORD_OVERHEAD
On Wed, Nov 23, 2016 at 04:44:39AM -0500, kan.liang@...el.com wrote:
> +struct perf_overhead_entry {
> + __u32 cpu;
> + __u64 nr;
> + __u64 time;
> +};
> +void perf_log_overhead(struct perf_event *event, u32 type,
> + struct perf_overhead_entry *entry)
> +{
> + struct perf_output_handle handle;
> + struct perf_sample_data sample;
> + int ret;
> +
> + struct {
> + struct perf_event_header header;
> + u32 type;
There's two u32 sized holes here.
> + struct perf_overhead_entry overhead;
> + } overhead_event = {
> + .header = {
> + .type = PERF_RECORD_OVERHEAD,
> + .misc = 0,
> + .size = sizeof(overhead_event),
> + },
.type = type,
.overhead = *event,
> + };
> + overhead_event.type = type;
> + memcpy(&overhead_event.overhead, entry, sizeof(overhead_event.overhead));
Do the above named initialization instead.
> +
> + perf_event_header__init_id(&overhead_event.header, &sample, event);
> + ret = perf_output_begin(&handle, event, overhead_event.header.size);
> +
> + if (ret)
> + return;
> +
> + perf_output_put(&handle, overhead_event);
> + perf_event__output_id_sample(event, &handle, &sample);
> +
> + perf_output_end(&handle);
> + memset(entry, 0, sizeof(*entry));
> +}
Powered by blists - more mailing lists