Messages in this thread | | | From | "Rafael J. Wysocki" <> | Subject | Re: [PATCH] Use extents for recording what swap is allocated. | Date | Tue, 24 Oct 2006 10:43:04 +0200 |
| |
On Tuesday, 24 October 2006 01:04, Nigel Cunningham wrote: > Hi. > > On Mon, 2006-10-23 at 17:32 +0200, Pavel Machek wrote: > > Hi! > > > > > Switch from bitmaps to using extents to record what swap is allocated; > > > they make more efficient use of memory, particularly where the allocated > > > storage is small and the swap space is large. > > > > > This is also part of the ground work for implementing support for > > > supporting multiple swap devices. > > > > bitmaps were more efficient and longer than original code... I did not > > _like_ them, but they are in now. I'd hate to change the code again, > > for what, 0.5% gain? > > 0.5% of what? This is part of what is needed to implement support for > multiple swap devices. You could extend what you already have, > implementing bitmaps that require a bit for every page of swap the user > has swapon'd, but that doesn't seem efficient to me.
I agree. Further, I though I would change the bitmaps thing at some point, but there still are more urgent things to do. ;-)
> > ...and this is still longer than bitmaps.
Yes, it is. Still I'd like to have a thorough look at it. The idea is fine by me.
> > And SNAPSHOT_GET_SWAP_PAGE seems to support multiple swap spaces > > already. > > It may do, but swap.c certainly doesn't. It supports exactly one device.
That's correct.
Greetings, Rafael
-- You never change things by fighting the existing reality. R. Buckminster Fuller - 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/
| |