Re: [resent PATCH] Re: very slow parallel read performance

Daniel Phillips
2001-08-26T19:39:49Z

On August 26, 2001 08:39 pm, Rik van Riel wrote:
> On Sun, 26 Aug 2001, Daniel Phillips wrote:
>
> > There's an obvious explanation for the high loadavg people are seeing
> > when their systems go into thrash mode: when free is exhausted, every
> > task that fails to get a block in __alloc_pages will become
> > PF_MEMALLOC and start scanning.
>
> If you ever tested this, you'd know this is not true.

Look at this, supplied by Nicolas Pitre in the thread "What version of the
kernel fixes these VM issues?":

> A couple sysrq-P at random intervals shows the CPU looping in the following
> functions:
>
> PC value System.map
> -------- ----------
> c0040d84 zone_inactive_plenty
> c0041024 try_to_swap_out
> c00216e0 cpu_sa1100_cache_clean_invalidate_range
> c00216d0 cpu_sa1100_cache_clean_invalidate_range
> c0041304 swap_out_mm
> c0041168 swap_out_pmd
> c0044324 __get_swap_page
> c0040d60 zone_inactive_plenty
> c0041128 swap_out_pmd
> c0040fec try_to_swap_out

--
Daniel