Re: [PATCH] thp: Disable THP if THP isn't supported by kernel
Wilco Dijkstra <[email protected]>
| Newsgroups | gmane.comp.lib.glibc.alpha |
|---|---|
| Message-ID | <PAWPR08MB89829EFE1CB90F09AB9A739283C02@PAWPR08MB8982.eurprd08.prod.outlook.com> |
Hi HJ, >> > Since DL_MAP_DEFAULT_THP_PAGESIZE is defined for x86-64, THP control >> > is to set to madvise by default. If THP is disabled in x86-64 kernel, >> > madvise (..., MADV_HUGEPAGE) returns -EINVAL to indicate that THP isn't >> > supported. Add _dl_thp_madvise to disable THP in this case. This >> > fixes BZ #34348. >> >> Are there enough calls in the loader that this is worthwhile? >> >> More importantly, does this actually work? I always get 0 result from madvise >> calls irrespectively of the madvise settings... Does it need a new kernel or is >> this target specific? > > You need to run it under a kernel without THP support. That is there is > no /sys/kernel/mm/transparent_hugepage/enabled. I see, but that makes it a rare case for some non-standard containers, so not worth trying to optimize for. I was hoping there is a magic way to efficiently get the madvise state... Cheers, Wilco