Re: [PATCH 02/12] perf tools: Separate generic code in dso_cache__read

From: Stanislav Fomichev
Date: Tue Apr 16 2019 - 13:17:19 EST


On 04/16, Jiri Olsa wrote:
> Moving file specific code in dso_cache__read function
> into separate file_read function. I'll add bpf specific
> code in following patches.
>
> Link: http://lkml.kernel.org/n/tip-7f7d717uzrqt5ka2xp29ige3@xxxxxxxxxxxxxx
> Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
> ---
> tools/perf/util/dso.c | 47 ++++++++++++++++++++++++-------------------
> 1 file changed, 26 insertions(+), 21 deletions(-)
>
> diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
> index cb6199c1390a..6baad22ec8a9 100644
> --- a/tools/perf/util/dso.c
> +++ b/tools/perf/util/dso.c
> @@ -794,6 +794,30 @@ dso_cache__memcpy(struct dso_cache *cache, u64 offset,
> return cache_size;
> }
>
> +static ssize_t file_read(struct dso *dso, struct machine *machine,
> + u64 offset, char *data)
> +{
> + ssize_t ret;
> +
> + pthread_mutex_lock(&dso__data_open_lock);
> +
> + /*
> + * dso->data.fd might be closed if other thread opened another
> + * file (dso) due to open file limit (RLIMIT_NOFILE).
> + */
> + try_to_open_dso(dso, machine);
> +
> + if (dso->data.fd < 0) {
> + dso->data.status = DSO_DATA_STATUS_ERROR;
pthread_mutex_unlock(&dso__data_open_lock) here?

> + return -errno;
> + }
> +
> + ret = pread(dso->data.fd, data, DSO__DATA_CACHE_SIZE, offset);
> + pthread_mutex_unlock(&dso__data_open_lock);
> +
> + return ret;
> +}
> +
> static ssize_t
> dso_cache__read(struct dso *dso, struct machine *machine,
> u64 offset, u8 *data, ssize_t size)
> @@ -803,37 +827,18 @@ dso_cache__read(struct dso *dso, struct machine *machine,
> ssize_t ret;
>
> do {
> - u64 cache_offset;
> + u64 cache_offset = offset & DSO__DATA_CACHE_MASK;
>
> cache = zalloc(sizeof(*cache) + DSO__DATA_CACHE_SIZE);
> if (!cache)
> return -ENOMEM;
>
> - pthread_mutex_lock(&dso__data_open_lock);
> -
> - /*
> - * dso->data.fd might be closed if other thread opened another
> - * file (dso) due to open file limit (RLIMIT_NOFILE).
> - */
> - try_to_open_dso(dso, machine);
> -
> - if (dso->data.fd < 0) {
> - ret = -errno;
> - dso->data.status = DSO_DATA_STATUS_ERROR;
> - break;
> - }
> -
> - cache_offset = offset & DSO__DATA_CACHE_MASK;
> -
> - ret = pread(dso->data.fd, cache->data, DSO__DATA_CACHE_SIZE, cache_offset);
> - if (ret <= 0)
> - break;
> + ret = file_read(dso, machine, cache_offset, cache->data);
>
> cache->offset = cache_offset;
> cache->size = ret;
> } while (0);
>
> - pthread_mutex_unlock(&dso__data_open_lock);
>
> if (ret > 0) {
> old = dso_cache__insert(dso, cache);
> --
> 2.17.2
>