Re: [PATCH] Allow a larger buffer for writes to cpuset files

[Paul Jackson <pj@sgi.com>]

Paul M wrote:
> @@ -1292,7 +1292,7 @@ static ssize_t cpuset_common_file_write(
>  	int retval = 0;
> 
>  	/* Crude upper limit on largest legitimate cpulist user might write. */
> -	if (nbytes > 100 + 6 * NR_CPUS)
> +	if (nbytes >= PAGE_SIZE)

On a system with 4 Kbyte pages, this imposes a tighter limit
if NR_CPUS is > 666.

On a system with 16 Kbyte pages, this imposes a tighter limit
if NR_CPUS is > 2714.

Those CPU counts don't look that futuristic to me.

And it makes the limit more aribitrary ... like what the heck does
that check have to do with PAGE_SIZE ?

How about coding for the possibility that either NR_CPUS or MAX_NUMNODES
is larger, and removing 'cpu' from the comment:

	/* Crude upper limit on largest legitimate list user might write. */
	if (nbytes > 100 + 6 * max(NR_CPUS, MAX_NUMNODES))

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