On 27/12/2018 00:53, Thomas Munro wrote:
> mmap and sysv were the same, but there
> did seem to be a measurable speed-up available at high client counts
> with kern.ipc.shm_use_phys=1 and thus for sysv only, for people
> prepared to set 3 sysctls and this proposed new GUC. Maybe the effect
> would be greater with bigger shared_buffers or smaller pages (this
> test ran on super pages)? More work required to figure that out.
Could you get a similar effect for mmap by using mlock() to prevent the
pages from being swapped?
--
Peter Eisentraut http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
