Messages in this thread | | | Date | Sun, 20 Jan 2002 17:45:31 -0500 (EST) | From | Shawn Starr <> | Subject | Re: Possible Idea with filesystem buffering. |
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But why should each filesystem have to have a different method of buffering/caching? that just doesn't fit the layered model of the kernel IMHO.
Shawn.
On Sun, 20 Jan 2002, Hans Reiser wrote:
> In version 4 of reiserfs, our plan is to implement writepage such that > it does not write the page but instead pressures the reiser4 cache and > marks the page as recently accessed. This is Linus's preferred method > of doing that. > > Personally, I think that makes writepage the wrong name for that > function, but I must admit it gets the job done, and it leaves writepage > as the right name for all filesystems that don't manage their own cache, > which is most of them. > > Hans > > Shawn wrote: > > >I've noticed that XFS's filesystem has a separate pagebuf_daemon to handle > >caching/buffering. > > > >Why not make a kernel page/caching daemon for other filesystems to use > >(kpagebufd) so that each filesystem can use a kernel daemon interface to > >handle buffering and caching. > > > >I found that XFS's buffering/caching significantly reduced I/O load on the > >system (with riel's rmap11b + rml's preempt patches and Andre's IDE > >patch). > > > >But I've not been able to acheive the same speed results with ReiserFS :-( > > > >Just as we have a filesystem (VFS) layer, why not have a buffering/caching > >layer for the filesystems to use inconjunction with the VM? > > > There is hostility to this from one of the VM maintainers. He is > concerned that separate caches were what they had before and they > behaved badly. I think that they simply coded them wrong the time > before. The time before, the pressure on the subcaches was uneven, with > some caches only getting pressure if the other caches couldn't free > anything, so of course it behaved badly. > > > > > > >Comments, suggestions, flames welcome ;) > > > >Shawn. > > > >- > >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/ > > > > > > > > >
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