Messages in this thread | | | Subject | Re: Linux-2.1.129.. | From | (Eric W. Biederman) | Date | 23 Nov 1998 13:16:26 -0600 |
| |
>>>>> "ST" == Stephen C Tweedie <sct@redhat.com> writes:
ST> That would be true if we didn't do the free_page_and_swap_cache trick. ST> However, doing that would require two passes: once by the swapper, and ST> once by shrink_mmap(): before actually freeing a page. This actually ST> sounds like a *very* good idea to explore, since it means that vmscan.c ST> will be concerned exclusively with returning mapped and anonymous pages ST> to the page cache. As a result, all of the actual freeing of pages will ST> be done in shrink_mmap(), which is the closest we can get to a true ST> self-balancing system for freeing memory.
There are a few other reasons this would be useful as well. 1) It resembles a 2 handed clock algorithm. So there would be some real page aging functionality. And we could reclaim pages that we are currently writing to disk.
2) We could remove the swap lock map.
I have wanted to suggest this for a while but I haven't had the time to carry it through. :(
ST> I'm going to check this out: I'll post preliminary benchmarks and a ST> patch for other people to test tomorrow. Getting the balancing right ST> will then just be a matter of making sure that try_to_swap_out gets ST> called often enough under normal running conditions. I'm open to ST> suggestions about that: we've never tried that sort of behaviour in the ST> vm to my knowledge.
We might want to look at the balance between the buffer cache writing and shrink_mmap. Because that is how those two systems interact already.
Eric
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/
| |