Re: [PATCH RFC UGLY] x86,mm,sched: make lazy TLB mode even lazier

2016-08-30 Thread Andy Lutomirski
On Mon, Aug 29, 2016 at 6:14 PM, H. Peter Anvin wrote: > On August 29, 2016 4:55:02 PM PDT, Andy Lutomirski > wrote: >>On Aug 29, 2016 7:54 AM, "Rik van Riel" wrote: >>> >>> On Sun, 2016-08-28 at 01:11 -0700, Andy Lutomirski wrote: >>> > On Aug 25, 2016 9:06 PM, "Rik van Riel" wrote: >>> > > >

Re: [PATCH RFC UGLY] x86,mm,sched: make lazy TLB mode even lazier

2016-08-29 Thread H. Peter Anvin
On August 29, 2016 4:55:02 PM PDT, Andy Lutomirski wrote: >On Aug 29, 2016 7:54 AM, "Rik van Riel" wrote: >> >> On Sun, 2016-08-28 at 01:11 -0700, Andy Lutomirski wrote: >> > On Aug 25, 2016 9:06 PM, "Rik van Riel" wrote: >> > > >> > > Subject: x86,mm,sched: make lazy TLB mode even lazier >> > >

Re: [PATCH RFC UGLY] x86,mm,sched: make lazy TLB mode even lazier

2016-08-29 Thread Andy Lutomirski
On Aug 29, 2016 7:54 AM, "Rik van Riel" wrote: > > On Sun, 2016-08-28 at 01:11 -0700, Andy Lutomirski wrote: > > On Aug 25, 2016 9:06 PM, "Rik van Riel" wrote: > > > > > > Subject: x86,mm,sched: make lazy TLB mode even lazier > > > > > > Lazy TLB mode can result in an idle CPU being woken up for

Re: [PATCH RFC UGLY] x86,mm,sched: make lazy TLB mode even lazier

2016-08-29 Thread Rik van Riel
On Thu, 2016-08-25 at 12:42 -0700, H. Peter Anvin wrote: > > +static void set_lazy_tlbstate_flush(int cpu) { > > + if (per_cpu(cpu_tlbstate.state, cpu) == TLBSTATE_LAZY) { > > + raw_spin_lock(&cpu_rq(cpu)->lock); > > + if (per_cpu(cpu_tlbstate.state, cpu) == > > TLBSTATE_LAZY

Re: [PATCH RFC UGLY] x86,mm,sched: make lazy TLB mode even lazier

2016-08-29 Thread Rik van Riel
On Sun, 2016-08-28 at 01:11 -0700, Andy Lutomirski wrote: > On Aug 25, 2016 9:06 PM, "Rik van Riel" wrote: > > > > Subject: x86,mm,sched: make lazy TLB mode even lazier > > > > Lazy TLB mode can result in an idle CPU being woken up for a TLB > > flush, when all it really needed to do was flush %

Re: [PATCH RFC UGLY] x86,mm,sched: make lazy TLB mode even lazier

2016-08-28 Thread Andy Lutomirski
On Aug 25, 2016 9:06 PM, "Rik van Riel" wrote: > > Subject: x86,mm,sched: make lazy TLB mode even lazier > > Lazy TLB mode can result in an idle CPU being woken up for a TLB > flush, when all it really needed to do was flush %cr3 before the > next context switch. > > This is mostly fine on bare me

Re: [PATCH RFC UGLY] x86,mm,sched: make lazy TLB mode even lazier

2016-08-25 Thread H. Peter Anvin
On August 25, 2016 12:04:59 PM PDT, Rik van Riel wrote: >Subject: x86,mm,sched: make lazy TLB mode even lazier > >Lazy TLB mode can result in an idle CPU being woken up for a TLB >flush, when all it really needed to do was flush %cr3 before the >next context switch. > >This is mostly fine on bare

Re: [PATCH RFC UGLY] x86,mm,sched: make lazy TLB mode even lazier

2016-08-25 Thread Rik van Riel
On Thu, 2016-08-25 at 12:42 -0700, H. Peter Anvin wrote: > On August 25, 2016 12:04:59 PM PDT, Rik van Riel > wrote: > > Subject: x86,mm,sched: make lazy TLB mode even lazier > > > > Lazy TLB mode can result in an idle CPU being woken up for a TLB > > flush, when all it really needed to do was fl

[PATCH RFC UGLY] x86,mm,sched: make lazy TLB mode even lazier

2016-08-25 Thread Rik van Riel
Subject: x86,mm,sched: make lazy TLB mode even lazier Lazy TLB mode can result in an idle CPU being woken up for a TLB flush, when all it really needed to do was flush %cr3 before the next context switch. This is mostly fine on bare metal, though sub-optimal from a power saving point of view, and