On Sun, 11 Apr 2010, Andrea Arcangeli wrote: > On Sun, Apr 11, 2010 at 08:22:04AM -0700, Linus Torvalds wrote: > > - magic libc malloc flags tghat are totally and utterly unrealistic in > > anything but a benchmark > > > > - by basically keeping one CPU totally busy doing defragmentation. > > This is a red herring. This is the last thing we want, and we'll run > even faster if we could make current glibc binaries to cooperate. But > this is a new feature and it'll require changing glibc slightly. So if it is a red herring, why the hell did you do your numbers with it? Also, talking about "changing glibc slightly" is another sign of just denial of reality. You realize that a lot of apps (especially the ones with large VM footprints) do not use glibc malloc at all, exactly because it has some bad properties particularly with threading? I saw people quote firefox mappings in this thread. You realize that firefox is one such application? > Future glibc will be optimal and it won't require khugepaged don't > worry. Sure. "All problems are imaginary". > I got crashes in page_mapcount != number of huge_pmd mapping the page > in split_huge_page because of the anon-vma bug, so I had to back it > out, this is why it's stable now. Ok. My deeper point really was that all the VM people seem to be in this circlejerk to improve performance, and it looks like nobody is even trying to fix the _existing_ problem (caused by another try to improve performance). I'm totally unimpressed with the whole circus partly exactly due to that. Linus -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>