On Wed, Feb 20, 2019 at 06:53:08PM -0800, Subhra Mazumdar wrote:Yes. In terms of idleness we have:
On 2/18/19 9:49 AM, Linus Torvalds wrote:I'm thinking oracle schedules quite a bit, right? Then you get massive
On Mon, Feb 18, 2019 at 9:40 AM Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:I tested 2 Oracle DB instances running OLTP on a 2 socket 44 cores system.
However; whichever way around you turn this cookie; it is expensive and nasty.Do you (or anybody else) have numbers for real loads?
Because performance is all that matters. If performance is bad, then
it's pointless, since just turning off SMT is the answer.
This is on baremetal, no virtualization.
overhead (as shown).
I plan to run some VM workloads.
The thing with virt workloads is that if they don't VMEXIT lots, they
also don't schedule lots (the vCPU stays running, nested scheduler
Also; like I wrote, it is quite possible there is some sibling rivalry
here, which can cause excessive rescheduling. Someone would have to
trace a workload and check.
My older patches had a condition that would not preempt a task for a
little while, such that it might make _some_ progress, these patches
don't have that (yet).