Re: [patch 06/11] showmem: Only walk spanned pages.

Johannes Weiner
2008-05-29T17:21:42Z

Hi,

Martin Schwidefsky <schwidefsky@de.ibm.com> writes:

> From: Heiko Carstens <heiko.carstens@de.ibm.com>
>
> Convert show_mem() so its nearly the same as on x86/powerpc.
> Gives us proper locking and we get also rid of the only use of max_mapnr.
> Also the number of pages was contained in an int which might not be
> sufficient not too far in the future.
>
> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
> ---
>
> arch/s390/mm/init.c | 42 +++++++++++++++++++++++-------------------
> 1 file changed, 23 insertions(+), 19 deletions(-)
>
> Index: quilt-2.6/arch/s390/mm/init.c
> ===================================================================
> --- quilt-2.6.orig/arch/s390/mm/init.c
> +++ quilt-2.6/arch/s390/mm/init.c
> @@ -44,30 +44,34 @@ char empty_zero_page[PAGE_SIZE] __attri
>
> void show_mem(void)
> {
> - int i, total = 0, reserved = 0;
> - int shared = 0, cached = 0;
> + unsigned long i, total = 0, reserved = 0;
> + unsigned long shared = 0, cached = 0;
> + unsigned long flags;
> struct page *page;
> + pg_data_t *pgdat;
>
> printk("Mem-info:\n");
> show_free_areas();
> - i = max_mapnr;
> - while (i-- > 0) {
> - if (!pfn_valid(i))
> - continue;
> - page = pfn_to_page(i);
> - total++;
> - if (PageReserved(page))
> - reserved++;
> - else if (PageSwapCache(page))
> - cached++;
> - else if (page_count(page))
> - shared += page_count(page) - 1;
> + for_each_online_pgdat(pgdat) {
> + pgdat_resize_lock(pgdat, &flags);
> + for (i = 0; i < pgdat->node_spanned_pages; i++) {
> + if (!pfn_valid(pgdat->node_start_pfn + i))
> + continue;
> + page = pfn_to_page(pgdat->node_start_pfn + i);
> + total++;
> + if (PageReserved(page))
> + reserved++;
> + else if (PageSwapCache(page))
> + cached++;
> + else if (page_count(page))
> + shared += page_count(page) - 1;
> + }
> + pgdat_resize_unlock(pgdat, &flags);
> }
> - printk("%d pages of RAM\n", total);
> - printk("%d reserved pages\n", reserved);
> - printk("%d pages shared\n", shared);
> - printk("%d pages swap cached\n", cached);
> -
> + printk("%ld pages of RAM\n", total);
> + printk("%ld reserved pages\n", reserved);
> + printk("%ld pages shared\n", shared);
> + printk("%ld pages swap cached\n", cached);

> printk("%lu pages dirty\n", global_page_state(NR_FILE_DIRTY));
> printk("%lu pages writeback\n", global_page_state(NR_WRITEBACK));
> printk("%lu pages mapped\n", global_page_state(NR_FILE_MAPPED));

These are redundant, check show_free_areas().

Hannes