Messages in this thread | | | From | Daniel Phillips <> | Subject | Re: Note describing poor dcache utilization under high memory pressure | Date | Wed, 30 Jan 2002 17:34:18 +0100 |
| |
On January 30, 2002 04:54 pm, Rik van Riel wrote: > On Wed, 30 Jan 2002, Daniel Phillips wrote: > > On January 30, 2002 03:46 pm, Rik van Riel wrote: > > > On Wed, 30 Jan 2002, Daniel Phillips wrote: > > > > > |-bash---bash---xinit-+-XFree86 > > > > | `-xfwm-+-xfce---gnome-terminal-+-bash---pstree > > > > > > It doesn't matter how deep the tree is, on exec() all > > > previously shared page tables will be blown away. > > > > > > In this part of the tree, I see exactly 2 processes > > > which could be sharing page tables (the two bash > > > processes). > > > > Sure, your point is that there is no problem and the speed of rmap on > > fork is not something to worry about? > > No. The point is that we should optimise for fork()+exec(), > not for a long series of consecutive fork()s all sharing the > same page tables.
Fork+exec is adequately optimized for. Fork+100 execs is supremely well optimized for. I'm entirely satisfied with the way the performance looks at this point, it will outdo anything we've seen to date. With Linus's write-protect-in-page-directory optimization there's not a lot more fat to be squeezed out, if any, and even without it, it will be a screamer. I think we've done this one, it's time to move on from here.
-- Daniel - 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/
| |