Messages in this thread |  | | Date | Tue, 30 Oct 2001 19:58:28 +0100 | From | Andrea Arcangeli <> | Subject | Re: need help interpreting 'free' output. |
| |
On Tue, Oct 30, 2001 at 10:28:29AM -0800, Linus Torvalds wrote: > want to lock the page - because locking the page means that you can pause > for a _long_ time waiting for the page to be written out when there is IO > pending.
ok I see what you mean, I agree (going to merge those important bits into my tree! :)
however those locking bits have nothing to do with exclusive_swap_page and the ealry cow I believe. exclusive_swap_page is faster than remove_exclusive_swap_page + only_swap_page as said in the earlier email and don't forget you somehow need the page lock too for remove_exclusive_swap_page.
The magic word here is "_trylock_" after your wait_on_page if the page wasn't uptodate, it's not that avoiding the early-cow or your remove_exclusive_swap_cache will change anything (they only slowdowns).
So in short we only need to replace the lock_page with a TryLockPage (plus your wait_on_page if page is not uptodate to catch the major faults) and here we go, faster than pre5.
In previous emails I was thinking at major faults, of course the whole optimization here is for the _minor_ faults were we don't need to block and where pre5aa1 blocks and where pre5 vanilla doesn't block! Very good point.
Andrea - 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/
|  |