Messages in this thread |  | | Date | Wed, 10 Jan 2001 11:27:03 -0800 | From | "David S. Miller" <> | Subject | Re: Subtle MM bug |
| |
Date: Wed, 10 Jan 2001 11:03:21 -0800 (PST) From: Linus Torvalds <torvalds@transmeta.com>
"Feel free to try" is definitely the open source motto.
I basically came to the conclusion that it sucks when I gave it a go.
In my scheme I tried to save space by using very small descriptors to keep track of anonymous areas in processes. This was essentially a vma->vm_anon pointer that kept track of the pages for you.
After trying to fight this for a few days I determined that this doesn't work at all because of how COW dups the pages around on you. Also it was a devil to work out anonymous pages created due to writes to private mmaps of a file, as soon as one of these were made for the first time on a vma you had to cook up one of the anon descriptors.
Yeah, I got the anon descriptor down to 2 pointers and an atomic counter, but it didn't work so this achievement was worthless :-)
There are a few approaches that work, but they tend to take up too much space to be considerable, as Linus mentioned.
Later, David S. Miller davem@redhat.com - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
|  |