On Mon, Aug 24, 2015 at 11:12 PM, James Hartshorn <jhartshorn@xxxxxxxxxxxxx> wrote: > Hi, > > > I've been struggling with transparent hugepage performance issues, and can't > seem to find anyone who actually uses it intentionally. Virtually every > database that runs on linux however recommends disabling it or setting it to > madvise. I'm referring to: > > > /sys/kernel/mm/transparent_hugepage/enabled > > > I asked on the internet > http://unix.stackexchange.com/questions/201906/does-anyone-actually-use-and-benefit-from-transparent-huge-pages > and got no responses there. > > > > Independently I noticed > > > "sysctl: The scan_unevictable_pages sysctl/node-interface has been disabled > for lack of a legitimate use case. If you have one, please send an email to > linux-mm@xxxxxxxxx." > > > And thought wow that's exactly what should be done to transparent hugepages. > > > Thoughts? THP works very well when system has a lot of free memory. Probably default should be weakened to "only if we have tons of free memory". For example allocate THP pages atomically, only if buddy allocator already has huge pages. Also them could be pre-zeroed in background. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>