[AMD Official Use Only - General] > -----Original Message----- > From: Yang, WenYou > Sent: Wednesday, March 29, 2023 5:43 PM > To: Peter Zijlstra <peterz@xxxxxxxxxxxxx> > Cc: Deucher, Alexander <Alexander.Deucher@xxxxxxx>; Koenig, Christian > <Christian.Koenig@xxxxxxx>; Pan, Xinhui <Xinhui.Pan@xxxxxxx>; Quan, Evan > <Evan.Quan@xxxxxxx>; Limonciello, Mario <Mario.Limonciello@xxxxxxx>; > bp@xxxxxxxxx; jpoimboe@xxxxxxxxxx; Phillips, Kim <kim.phillips@xxxxxxx>; > tglx@xxxxxxxxxxxxx; Yuan, Perry <Perry.Yuan@xxxxxxx>; Liang, Richard qi > <Richardqi.Liang@xxxxxxx>; Li, Ying <YING.LI@xxxxxxx>; Liu, Kun > <Kun.Liu2@xxxxxxx>; gpiccoli@xxxxxxxxxx; amd-gfx@xxxxxxxxxxxxxxxxxxxxx; > linux-kernel@xxxxxxxxxxxxxxx > Subject: RE: [PATCH v3 1/2] cpu/smt: add a notifier to notify the SMT changes > > [AMD Official Use Only - General] > > > > > -----Original Message----- > > From: Peter Zijlstra <peterz@xxxxxxxxxxxxx> > > Sent: Wednesday, March 29, 2023 4:50 PM > > To: Yang, WenYou <WenYou.Yang@xxxxxxx> > > Cc: Deucher, Alexander <Alexander.Deucher@xxxxxxx>; Koenig, Christian > > <Christian.Koenig@xxxxxxx>; Pan, Xinhui <Xinhui.Pan@xxxxxxx>; Quan, > > Evan <Evan.Quan@xxxxxxx>; Limonciello, Mario > > <Mario.Limonciello@xxxxxxx>; bp@xxxxxxxxx; jpoimboe@xxxxxxxxxx; > > Phillips, Kim <kim.phillips@xxxxxxx>; tglx@xxxxxxxxxxxxx; Yuan, Perry > > <Perry.Yuan@xxxxxxx>; Liang, Richard qi <Richardqi.Liang@xxxxxxx>; Li, > > Ying <YING.LI@xxxxxxx>; Liu, Kun <Kun.Liu2@xxxxxxx>; > > gpiccoli@xxxxxxxxxx; amd-gfx@xxxxxxxxxxxxxxxxxxxxx; > > linux-kernel@xxxxxxxxxxxxxxx > > Subject: Re: [PATCH v3 1/2] cpu/smt: add a notifier to notify the SMT > > changes > > > > Caution: This message originated from an External Source. Use proper > > caution when opening attachments, clicking links, or responding. > > > > > > On Wed, Mar 29, 2023 at 07:23:29AM +0000, Yang, WenYou wrote: > > > [AMD Official Use Only - General] > > > > ^^^ that has no business being in a public email. > > > > > Hi Peter, > > > > > > Thank you for your review. > > > > > > The purpose of the patch set is to improve the performance when > > > playing > > game for some AMD APUs with SMT enabled/disabled. > > > > > > When change the SMT state on the fly through " echo on/off > > > /sys/devices/system/cpu/smt/control", the kernel needs to send a > > message to notify PMFW to adjust a variable's value, which impacts the > performance. > > > > When top posting I normally ignore the email. When not wrapping email > > I typically get cranky. You 'win' *3* 'I cannot use email' trophies in a singly try. > > Surely AMD has a HOWTO somewhere you can read? > > Yes. It is my fault. Sorry. > > > > > So what do you want to have happen when someone goes and manually > > offlines all the SMT siblings using > > /sys/devices/system/cpu/cpu*/online > > ? > > I don't consider this situation. Any suggestions will be deeply appreciated. Hi Peter, I don't find a good method to handle this situation. Yes, manually offlining all the SMT sibling will get the same result of SMT disabling on the fly. Actually, the normal way to enable/disable SMT on the fly is to echo on/off > /sys/device/system/cpu/smt/control What are your opinions? Best Regards, Wenyou > > > > > I'm thinking that wants the same PMFW (whatever the heck that is) > > notification change done, right? > > > > If the answer is "yes", then your patch does not meet the goals and is > > inadequate. > > Yes. Need to improve. > > Thank you. > Wenyou
