Re: [LTP] [PATCH 2/4] memlib: add check_shmmax to check shm_size not bigger than shmmax

[Caspar Z. <ca...@ca...>]

On 04/02/2012 04:34 PM, Wanlong Gao wrote:
> add a lib function to check the shm_size, make sure it's not
> bigger than shmmax.
> 
> Signed-off-by: Wanlong Gao <gao...@cn...>
> ---
>  testcases/kernel/mem/include/mem.h |    6 ++++++
>  testcases/kernel/mem/lib/mem.c     |   13 +++++++++++++
>  2 files changed, 19 insertions(+)
> 
> diff --git a/testcases/kernel/mem/include/mem.h b/testcases/kernel/mem/include/mem.h
> index 4c568cd..8f59483 100644
> --- a/testcases/kernel/mem/include/mem.h
> +++ b/testcases/kernel/mem/include/mem.h
> @@ -32,6 +32,10 @@ void testoom(int mempolicy, int lite, int numa);
>  
>  #define PATH_KSM		"/sys/kernel/mm/ksm/"
>  
> +/* HUGETLB */
> +
> +#define PATH_SHMMAX		"/proc/sys/kernel/shmmax"
> +
>  /*
>   * memory pointer to identify per process, MB unit, and byte like
>   * memory[process No.][MB unit No.][byte No.].
> @@ -73,4 +77,6 @@ void read_file(char *filename, char *retbuf);
>  void cleanup(void);
>  void setup(void);
>  
> +void check_shmmax(size_t *shm_size);
Hmmm, in this function, shm_size might be changed, while the name
"check_shmmax" looks more likely to be a read-only behavior. Would it
better be something like "update_shm_size"?

Anyway, others look good.

Reviewed-by: Caspar Zhang <ca...@ca...>

Thanks,
Caspar


> +
>  #endif
> diff --git a/testcases/kernel/mem/lib/mem.c b/testcases/kernel/mem/lib/mem.c
> index 35932af..8fd8c09 100644
> --- a/testcases/kernel/mem/lib/mem.c
> +++ b/testcases/kernel/mem/lib/mem.c
> @@ -786,3 +786,16 @@ void read_file(char *filename, char *retbuf)
>  		tst_brkm(TBROK|TERRNO, cleanup, "read %s", filename);
>  	close(fd);
>  }
> +
> +void check_shmmax(size_t *shm_size)
> +{
> +	char buf[BUFSIZ];
> +	size_t shmmax;
> +
> +	read_file(PATH_SHMMAX, buf);
> +	shmmax = SAFE_STRTOL(cleanup, buf, 0, LONG_MAX);
> +	if (*shm_size > shmmax) {
> +		tst_resm(TINFO, "Set shm_size to shmmax: %ld", shmmax);
> +		*shm_size = shmmax;
> +	}
> +}