On Thu, Aug 19, 2021 at 07:56:43PM +0100, Matthew Wilcox wrote:
> On Thu, Aug 19, 2021 at 11:26:46AM -0700, Darrick J. Wong wrote:
> > + printf("Dirtying memory.\n");
> > + fflush(stdout);
> > +
> > + /* Dirty the memory to force this program to be swapped out. */
> > + for (p = pstart; p < pend; p += pagesize)
> > + *p = 'X';
>
> What I liked about dhowells' program was that it checked whether the
> pages brought back in from swap were the same ones that had been written
> to swap. As a block filesystem person, you only know the misery of having
> swap go behind your back to the block device. As a network filesystem
> person, David is acutely aware of the misery of having to remember to
> use page_file_index() instead of page->index in order to avoid reading
> a page from the wrong offset in the swap partition.
>
> Yes, our swap code is nasty in many different ways, why do you ask?
Wheeee, I'll go change it to store per-page data in each page and check
it on the way back.
--D
