Re: buffers vs. pages vs. kernel speed

Dr. Werner Fink (
Thu, 12 Jun 1997 17:26:44 +0200

A few hour ago I've wrote:

> Hmmm ... in case of mem=4MB and a buffer request larger or equal than 4MB
> Matthias's state machine fix runs into trouble. In such situations
> the buffer of the requesting process must shrinked to get enough free mem
> space for the new buffer ... try_to_free_page should not turn to shm_swap or
> swap_out but have to shrink the buffer/shared pages. This costs cpu time
> but it's really necessary to get the requesting programm (mke2fs) running.
> On the other hand: If there is much more mem space as the requested mem
> Matthias's state machine fix is the better choice to save cpu time and
> to avoid the nasty sig7/Couldn't_get_free_page problem. That is also what
> Gerard reports.
> We need a switch for both situations. Also my previous hack in shrink_mmap
> is a bad one for the first scenario.

... maybe true maybe wrong ... with the activation of try_to_free_page as
Hubert wrote, it IS possible to run mke2fs on a mem=4MB system :-)))

Sorry for the inconvenience