Re: [PATCH] xfs_io: add command line option -M to run as multi threaded process

[Christoph Hellwig <hch@infradead.org>]

On Fri, Oct 14, 2016 at 11:44:38PM +0300, Amir Goldstein wrote:
> xfs_io -M will start by spawning an idle thread.
> The purpose of this idle thread is to test io from a multi threaded
> process. With single threaded process, the file table is not shared
> and file structs are not reference counted.
> 
> So in order to detect file struct reference leaks, spawning an idle
> thread will do the trick.
> 
> Signed-off-by: Amir Goldstein <amir73il@gmail.com>
> ---
>  io/Makefile |  2 +-
>  io/init.c   | 32 +++++++++++++++++++++++++++++++-
>  2 files changed, 32 insertions(+), 2 deletions(-)
> 
> diff --git a/io/Makefile b/io/Makefile
> index 1997ca9..032a8c7 100644
> --- a/io/Makefile
> +++ b/io/Makefile
> @@ -13,7 +13,7 @@ CFILES = init.c \
>  	mmap.c open.c parent.c pread.c prealloc.c pwrite.c seek.c shutdown.c \
>  	sync.c truncate.c reflink.c
>  
> -LLDLIBS = $(LIBXCMD) $(LIBHANDLE)
> +LLDLIBS = $(LIBXCMD) $(LIBHANDLE) $(LIBPTHREAD)
>  LTDEPENDENCIES = $(LIBXCMD) $(LIBHANDLE)
>  LLDFLAGS = -static-libtool-libs
>  
> diff --git a/io/init.c b/io/init.c
> index 6b88cc6..1d1b97f 100644
> --- a/io/init.c
> +++ b/io/init.c
> @@ -16,6 +16,7 @@
>   * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
>   */
>  
> +#include <pthread.h>
>  #include "platform_defs.h"
>  #include "command.h"
>  #include "input.h"
> @@ -25,6 +26,7 @@
>  char	*progname;
>  int	exitcode;
>  int	expert;
> +int	multithreaded;
>  size_t	pagesize;
>  struct timeval stopwatch;
>  
> @@ -141,7 +143,7 @@ init(
>  	pagesize = getpagesize();
>  	gettimeofday(&stopwatch, NULL);
>  
> -	while ((c = getopt(argc, argv, "ac:dFfmp:nrRstTVx")) != EOF) {
> +	while ((c = getopt(argc, argv, "ac:dFfmMp:nrRstTVx")) != EOF) {
>  		switch (c) {
>  		case 'a':
>  			flags |= IO_APPEND;
> @@ -166,6 +168,9 @@ init(
>  				exit(1);
>  			}
>  			break;
> +		case 'M':
> +			multithreaded = 1;
> +			break;
>  		case 'n':
>  			flags |= IO_NONBLOCK;
>  			break;
> @@ -213,12 +218,37 @@ init(
>  	add_check_command(init_check_command);
>  }
>  
> +/*
> + * The purpose of this idle thread is to test io from a multi threaded process.
> + * With single threaded process, the file table is not shared and file structs
> + * are not reference counted. So in order to detect file struct reference
> + * leaks, spawning an idle thread will do the trick.
> + */
> +void *
> +idle_loop(void *arg)
> +{
> +	for (;;) pause();

Indentation issue: the pause should on a line of its own.

Otherwise this looks fine to me:

Reviewed-by: Christoph Hellwig <hch@lst.de>