Re: [PATCH v2 2/4] perf record: bind the AIO user space buffers to nodes

[Jiri Olsa <jolsa@redhat.com>]

On Mon, Dec 24, 2018 at 03:24:36PM +0300, Alexey Budankov wrote:
> 
> Allocate and bind AIO user space buffers to the memory nodes
> that mmap kernel buffers are bound to.
> 
> Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
> ---
> Changes in v2:
> - implemented perf_mmap__aio_alloc, perf_mmap__aio_free, perf_mmap__aio_bind 
>   and put HAVE_LIBNUMA_SUPPORT #ifdefs in there
> ---
>  tools/perf/util/mmap.c | 49 ++++++++++++++++++++++++++++++++++++++++--
>  1 file changed, 47 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/perf/util/mmap.c b/tools/perf/util/mmap.c
> index e68ba754a8e2..742fa9a8e498 100644
> --- a/tools/perf/util/mmap.c
> +++ b/tools/perf/util/mmap.c
> @@ -10,6 +10,9 @@
>  #include <sys/mman.h>
>  #include <inttypes.h>
>  #include <asm/bug.h>
> +#ifdef HAVE_LIBNUMA_SUPPORT
> +#include <numaif.h>
> +#endif
>  #include "debug.h"
>  #include "event.h"
>  #include "mmap.h"
> @@ -154,6 +157,46 @@ void __weak auxtrace_mmap_params__set_idx(struct auxtrace_mmap_params *mp __mayb
>  }
>  
>  #ifdef HAVE_AIO_SUPPORT
> +
> +#ifdef HAVE_LIBNUMA_SUPPORT
> +static void perf_mmap__aio_alloc(void **data, size_t len)
> +{
> +	*data = mmap(NULL, len, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, 0, 0);
> +}

please make perf_mmap__aio_alloc return the pointer,
I dont see a need for **data arg

also perf_mmap__ preffix indicates it's function over
'struct perf_mmap', which should be the first arg..
not sure, but perhaps that could make the code also
simpler, like:

static int perf_mmap__aio_alloc(struct perf_mmap *, int index);
static int perf_mmap__aio_bind(struct perf_mmap *, int index, int affinity);
static void perf_mmap__aio_free(struct perf_mmap *, int index);

jirka