> On Tue, 9 Nov 2010 16:28:02 +0900 (JST), KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> wrote: > > So, I don't think application developers will use fadvise() aggressively > > because we don't have a cross platform agreement of a fadvice behavior. > > > I strongly disagree. For a long time I have been trying to resolve > interactivity issues caused by my rsync-based backup script. Many kernel > developers have said that there is nothing the kernel can do without > more information from user-space (e.g. cgroups, madvise). While cgroups > help, the fix is round-about at best and requires configuration where > really none should be necessary. The easiest solution for everyone > involved would be for rsync to use FADV_DONTNEED. The behavior doesn't > need to be perfectly consistent between platforms for the flag to be > useful so long as each implementation does something sane to help > use-once access patterns. > > People seem to mention frequently that there are no users of > FADV_DONTNEED and therefore we don't need to implement it. It seems like > this is ignoring an obvious catch-22. Currently rsync has no fadvise > support at all, since using[1] the implemented hints to get the desired > effect is far too complicated^M^M^M^Mhacky to be considered > merge-worthy. Considering the number of Google hits returned for > fadvise, I wouldn't be surprised if there were countless other projects > with this same difficulty. We want to be able to tell the kernel about > our useage patterns, but the kernel won't listen. Because we have an alternative solution already. please try memcgroup :) -- 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/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>