Messages in this thread | | | Date | Thu, 07 Mar 2002 12:56:44 -0800 | From | Andrew Morton <> | Subject | Re: [RFC] Arch option to touch newly allocated pages |
| |
Rik van Riel wrote: > > On Thu, 7 Mar 2002, Andrew Morton wrote: > > Daniel Phillips wrote: > > > > > > a GFP flag that says 'fail if this looks hard to get'. > > > > Something like that would provide a solution to the > > readahead thrashing problem. > > Nope. Readahead pages are clean and very easy to evict, so > it's still trivial to evict all the pages from another readahead > window because everybody's readahead window is too large. >
I was thinking an explicit GFP_READAHEAD and PG_readahead. Where a GFP_READAHEAD allocation would fail if it can't find any non-readahead pages. And it would fail if it had to perform I/O.
That's not nice - it'd result in large LRU walks. But it'd be better than the 10x slowdown which readahead thrashing causes.
Any clever ideas?
- - 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/
| |