On Wednesday 12 September 2007 07:48, Christoph Lameter wrote: > On Tue, 11 Sep 2007, Nick Piggin wrote: > > But that's not my place to say, and I'm actually not arguing that high > > order pagecache does not have uses (especially as a practical, > > shorter-term solution which is unintrusive to filesystems). > > > > So no, I don't think I'm really going against the basics of what we > > agreed in Cambridge. But it sounds like it's still being billed as > > first-order support right off the bat here. > > Well its seems that we have different interpretations of what was agreed > on. My understanding was that the large blocksize patchset was okay > provided that I supply an acceptable mmap implementation and put a > warning in. Yes. I think we differ on our interpretations of "okay". In my interpretation, it is not OK to use this patch as a way to solve VM or FS or IO scalability issues, especially not while the alternative approaches that do _not_ have these problems have not been adequately compared or argued against. > > But even so, you can just hold an open fd in order to pin the dentry you > > want. My attack would go like this: get the page size and allocation > > group size for the machine, then get the number of dentries required to > > fill a slab. Then read in that many dentries and pin one of them. Repeat > > the process. Even if there is other activity on the system, it seems > > possible that such a thing will cause some headaches after not too long a > > time. Some sources of pinned memory are going to be better than others > > for this of course, so yeah maybe pagetables will be a bit easier (I > > don't know). > > Well even without slab targeted reclaim: Mel's antifrag will sort the > dentries into separate blocks of memory and so isolate the issue. So even after all this time you do not understand what the fundamental problem is with anti-frag and yet you are happy to waste both our time in endless flamewars telling me how wrong I am about it. Forgive me if I'm starting to be rude, Christoph. This is really irritating. - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
