lkml.org 
[lkml]   [2005]   [Nov]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH 3/5] Swap Migration V5: migrate_pages() function
From
Date
On Tue, 2005-11-01 at 02:06 -0600, Rob Landley wrote:
> On Monday 31 October 2005 21:12, Christoph Lameter wrote:
> > Page migration support in vmscan.c
>
> This has no #ifdef SWAP:
>
> > + if (PageSwapCache(page)) {
> > + swp_entry_t swap = { .val = page_private(page) };
> > + add_to_swapped_list(swap.val);
> > + __delete_from_swap_cache(page);
> > + write_unlock_irq(&mapping->tree_lock);
> > + swap_free(swap);
> > + __put_page(page); /* The pagecache ref */
> > + return 1;
> > + }
>
> But what you removed did:
>
> > -#ifdef CONFIG_SWAP
> > - if (PageSwapCache(page)) {
> > - swp_entry_t swap = { .val = page_private(page) };
> > - add_to_swapped_list(swap.val);
> > - __delete_from_swap_cache(page);
> > - write_unlock_irq(&mapping->tree_lock);
> > - swap_free(swap);
> > - __put_page(page); /* The pagecache ref */
> > - goto free_it;
> > - }
> > -#endif /* CONFIG_SWAP */
>
> What happens if you build without swap?

You don't need an explicit #ifdef.

PageSwapCache() has an #ifdef for its declaration which gets it down to
'0'. That should get gcc to completely kill the if(){} block, with no
explicit #ifdef.

-- Dave

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-11-01 10:02    [W:0.062 / U:1.268 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site