Re: [PATCH] sort: use posix_fadvise to announce access patterns on files opened for reading

[Pádraig Brady]

On 02/03/10 11:42, Erik Auerswald wrote:
> Hi,
>
> On Mon, Mar 01, 2010 at 05:33:38PM -0800, Joey Degges wrote:
> > Were you sure to remount your devices to clear the cache before running
> > these tests? While testing this patch early on the cache caused me many
> > incorrect readings. Another approach I took to clear the cache was to fill
> > up all of my RAM with some other process.
>
> To clear the caches you can use
>
> echo 3>  /proc/sys/vm/drop_caches

In my testing I left the inode cache alone
for my mechanical disk and used:
  echo 1 > /proc/sys/vm/drop_caches

For spinning the CPU I just used:
  openssl speed

cheers,
Pádraig.