Thanks for detailed info. But I don't think it's a big problem. Arenas are returned to system by chance. So other processes shouldn't relying to it.
And I don't propose to stop returning arena to system. I just mean per pool (part of arena) MADV_DONTNEED can reduce RSS. If we use very large arena, or stop returning arena to system, it can be problem. Regards, On Thu, Jun 1, 2017 at 6:05 PM, Siddhesh Poyarekar <siddh...@gotplt.org> wrote: > On Thursday 01 June 2017 01:53 PM, INADA Naoki wrote: >> * On Linux, madvice(..., MADV_DONTNEED) can be used. > > madvise does not reduce the commit charge in the Linux kernel, so in > high consumption scenarios (and where memory overcommit is disabled or > throttled) you'll see programs dying with OOM despite the MADV_DONTNEED. > The way we solved it in glibc was to use mprotect to drop PROT_READ and > PROT_WRITE in blocks that we don't need when we detect that the system > is not configured to overcommit (using /proc/sys/vm/overcommit_memory). > You'll need to fix the protection again though if you want to reuse the > block. > > Siddhesh _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
