On Wed, Sep 05, 2018 at 10:19:56AM +0300, Alexey Budankov wrote:
>
> The map->data buffers are used to preserve map->base profiling data
> for writing to disk. AIO map->cblocks are used to queue corresponding
> map->data buffers for asynchronous writing. map->cblocks objects are
> located in the last page of every map->data buffer.
>
> Signed-off-by: Alexey Budankov <alexey.budan...@linux.intel.com>
> ---
> Changes in v7:
> - implemented handling record.aio setting from perfconfig file
> Changes in v6:
> - adjusted setting of priorities for cblocks;
> Changes in v5:
> - reshaped layout of data structures;
> - implemented --aio option;
> Changes in v4:
> - converted mmap()/munmap() to malloc()/free() for mmap->data buffer
> management
> Changes in v2:
> - converted zalloc() to calloc() for allocation of mmap_aio array,
> - cleared typo and adjusted fallback branch code;
> ---
> tools/perf/builtin-record.c | 15 ++++++++++++-
> tools/perf/perf.h | 1 +
> tools/perf/util/evlist.c | 7 +++---
> tools/perf/util/evlist.h | 3 ++-
> tools/perf/util/mmap.c | 53
> +++++++++++++++++++++++++++++++++++++++++++++
> tools/perf/util/mmap.h | 6 ++++-
> 6 files changed, 79 insertions(+), 6 deletions(-)
>
> diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
> index 22ebeb92ac51..f17a6f9cb1ba 100644
> --- a/tools/perf/builtin-record.c
> +++ b/tools/perf/builtin-record.c
> @@ -326,7 +326,8 @@ static int record__mmap_evlist(struct record *rec,
>
> if (perf_evlist__mmap_ex(evlist, opts->mmap_pages,
> opts->auxtrace_mmap_pages,
> - opts->auxtrace_snapshot_mode) < 0) {
> + opts->auxtrace_snapshot_mode,
> + opts->nr_cblocks) < 0) {
> if (errno == EPERM) {
> pr_err("Permission error mapping pages.\n"
> "Consider increasing "
> @@ -1287,6 +1288,8 @@ static int perf_record_config(const char *var, const
> char *value, void *cb)
> var = "call-graph.record-mode";
> return perf_default_config(var, value, cb);
> }
> + if (!strcmp(var, "record.aio"))
> + rec->opts.nr_cblocks = strtol(value, NULL, 0);
>
> return 0;
> }
> @@ -1519,6 +1522,7 @@ static struct record record = {
> .default_per_cpu = true,
> },
> .proc_map_timeout = 500,
> + .nr_cblocks = 2
> },
> .tool = {
> .sample = process_sample_event,
> @@ -1678,6 +1682,8 @@ static struct option __record_options[] = {
> "signal"),
> OPT_BOOLEAN(0, "dry-run", &dry_run,
> "Parse options then exit"),
> + OPT_INTEGER(0, "aio", &record.opts.nr_cblocks,
> + "asynchronous trace write operations (min: 1, max: 32,
> default: 2)"),
ok, so this got silently added in recent versions and I couldn't
find any justification for it.. why do we use more aio blocks for
single map now? also why the default is 2?
the option should be more specific like 'aio-blocks'
the change is difficult enough.. we should start simple and add
these additions with proper justification in separate patches
thanks,
jirka
