Re: [PATCH 1/4] sched,time: remove non-power-of-two divides from __acct_update_integrals

[Thomas Gleixner]

On Sun, 31 Jan 2016, r...@redhat.com wrote:
> @@ -93,9 +93,9 @@ void xacct_add_tsk(struct taskstats *stats, struct 
> task_struct *p)
>  {
>       struct mm_struct *mm;
>  
> -     /* convert pages-usec to Mbyte-usec */
> -     stats->coremem = p->acct_rss_mem1 * PAGE_SIZE / MB;
> -     stats->virtmem = p->acct_vm_mem1 * PAGE_SIZE / MB;
> +     /* convert pages-nsec/1024 to Mbyte-usec, see __acct_update_integrals */
> +     stats->coremem = p->acct_rss_mem1 * PAGE_SIZE / (1000 * KB);
> +     stats->virtmem = p->acct_vm_mem1 * PAGE_SIZE / (1000 * KB);

You replace "/ (1024 * 1024)" by "/ (1000 * 1024). So that's introducing a non
power of 2 division instead of removing one and wont compile on systems which
do not have a 64/32 division in hardware.

Thanks,

        tglx