[AMD Official Use Only - General]
> -----Original Message----- > From: Yang, WenYou > Sent: Wednesday, March 29, 2023 5:43 PM > To: Peter Zijlstra <[email protected]> > Cc: Deucher, Alexander <[email protected]>; Koenig, Christian > <[email protected]>; Pan, Xinhui <[email protected]>; Quan, Evan > <[email protected]>; Limonciello, Mario <[email protected]>; > [email protected]; [email protected]; Phillips, Kim <[email protected]>; > [email protected]; Yuan, Perry <[email protected]>; Liang, Richard qi > <[email protected]>; Li, Ying <[email protected]>; Liu, Kun > <[email protected]>; [email protected]; [email protected]; > [email protected] > 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 <[email protected]> > > Sent: Wednesday, March 29, 2023 4:50 PM > > To: Yang, WenYou <[email protected]> > > Cc: Deucher, Alexander <[email protected]>; Koenig, Christian > > <[email protected]>; Pan, Xinhui <[email protected]>; Quan, > > Evan <[email protected]>; Limonciello, Mario > > <[email protected]>; [email protected]; [email protected]; > > Phillips, Kim <[email protected]>; [email protected]; Yuan, Perry > > <[email protected]>; Liang, Richard qi <[email protected]>; Li, > > Ying <[email protected]>; Liu, Kun <[email protected]>; > > [email protected]; [email protected]; > > [email protected] > > 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
