Re: [PATCH][1/2] adjust dirty threshold for lowmem-only mappings

Jens Axboe
2005-01-02T15:13:15Z

On Sat, Dec 25 2004, William Lee Irwin III wrote:
> On Sat, 25 Dec 2004, Andrea Arcangeli wrote:
> >> the first place? If that happens it means you're under a lowmem
> >> shortage, something you apparently ruled out when you said
> >> lowmem_reserve couldn't help your workload.
>
> On Sat, Dec 25, 2004 at 12:59:10PM -0500, Rik van Riel wrote:
> > Let me explain a 3rd time:
> [...]
> > If you have any more questions as to why the bug happens, don't
> > hesitate to ask and I'll explain you why this problem happens.
>
> This is an old and well-known problem.
>
> Lifting the artificial lowmem restrictions on blockdev mappings
> (thereby nuking mapping->gfp_mask altogether) would resolve a number of
> problems, not that anything making that much sense could ever happen.

It should be lifted for block devices, it doesn't make any sense.
mapping->gfp_mask is still needed for things like loop though, so it
cannot be nuked.

--
Jens Axboe