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AJvYcCWu2JknyIEw00JC+rhVKEI3AwTk9sF51ZgQIemanv5FOchT+MAJXmLAvQ5nF7mWECScLsxsdVPTxdgDRx4=@vger.kernel.org X-Gm-Message-State: AOJu0YzOMbX9vHX8FE3lj3r86fOM7FuaD/8SXkygtnzRawXxyr2uRQgm zc1K1epEAoUWLiyIVgmovoodny/bch20dxM2aXxFD6ylbOtdkpM21WfVFDboD/kRXHTXW5+GqRf azNcFgi2EsyqcvgjfWnuYSdusGlD1utg= X-Gm-Gg: ASbGnct1SG8WB/y3Lvxiek6hZB75I5c4AlN4m+AJLTMNT750v1hI9WBqUwB5Cjkou6B VryZGqktCZnwKY/fQX3l+g5IA8cfGwi3XrWYFaq2uLcAhd8pKTYclInWqckCl/9FDeeTFeEiBWM OLtcb/Q9UIbZROIlrHX675H26w5oW3bLF5ZQqxqLYdH0HkppD1umaxKXJ6GEhJznY47Sp1QSrif FQQPatOJxsN9bE7HCE= X-Google-Smtp-Source: AGHT+IHMkSl/ptmGGhKdk9o/G/iYd9nV6mxPKNnrNLrjJ4Z1XGzXiiAN67BtmKbuHWnf8+QOK5wXqrVGylyKQuCEKMk= X-Received: by 2002:a05:622a:1147:b0:4b0:8c29:f6e1 with SMTP id d75a77b69052e-4b291a66088mr29672571cf.7.1755688175303; Wed, 20 Aug 2025 04:09:35 -0700 (PDT) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <20250812093339.8895-1-xuewen.yan@unisoc.com> <8a84e658-1c2d-4380-8979-e1cc5bf5768d@arm.com> <7b3601d1-f39e-4691-84d1-8aa397e06535@arm.com> In-Reply-To: <7b3601d1-f39e-4691-84d1-8aa397e06535@arm.com> From: Xuewen Yan Date: Wed, 20 Aug 2025 19:09:23 +0800 X-Gm-Features: Ac12FXx54VwkQZO70uvSr64Ev9lIe8yqsbzsqKJQHAWCNRSQqkfu53haKfJk4FY Message-ID: Subject: Re: [RFC PATCH] sched/feec: Simplify the traversal of pd'cpus To: Dietmar Eggemann Cc: Christian Loehle , Xuewen Yan , mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, vdonnefort@google.com, ke.wang@unisoc.com, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Tue, Aug 19, 2025 at 10:01=E2=80=AFPM Dietmar Eggemann wrote: > > On 19.08.25 03:02, Xuewen Yan wrote: > > On Mon, Aug 18, 2025 at 11:24=E2=80=AFPM Dietmar Eggemann > > wrote: > >> > >> On 18.08.25 12:05, Xuewen Yan wrote: > >>> On Fri, Aug 15, 2025 at 9:01=E2=80=AFPM Dietmar Eggemann > >>> wrote: > >>>> > >>>> On 14.08.25 10:52, Xuewen Yan wrote: > >>>>> Hi Dietmar, > >>>>> > >>>>> On Thu, Aug 14, 2025 at 4:46=E2=80=AFPM Dietmar Eggemann > >>>>> wrote: > >>>>>> > >>>>>> On 12.08.25 10:33, Xuewen Yan wrote: > > [...] > > >> Looks like we do need also the sd cpumask here. > >> > >> Consider this tri-gear system: > >> > >> # cat /sys/devices/system/cpu/cpu*/cpu_capacity > >> 160 > >> 160 > >> 160 > >> 160 > >> 498 > >> 498 > >> 1024 > >> 1024 > >> > >> and 2 exclusive cpusets cs1=3D{0-1,4,6} and cs2=3D{2-3,5,7}, so EAS is > >> possible in all 3 root_domains (/, /cs1, /cs2): > > > > Isn't your CPU an ARM Dynamiq architecture? > > In my understanding, for Dynamiq arch, there is only one MC domain... > > Did I miss something? > > Ah, should have mentioned that this is qemu. I used a dts file > (qemu-system-aarch64 ... -dtb foo.dtb) with individual > 'next-level-cache' entries for the CPUs {0-3}, {4-5} and {6-7} so that's > why you see MC & PKG. Removing those gives you a system with only MC: Thank you for your patience in explaining:) Looks like we do need also the sd cpumask here. Thanks! > > [ 106.986828] CPU2 attaching sched-domain(s): > [ 106.987846] domain-0: span=3D2-3,5,7 level=3DMC > [ 106.987941] groups: 2:{ span=3D2 cap=3D159 }, 3:{ span=3D3 cap=3D154= }, 5:{ > span=3D5 cap=3D495 }, 7:{ span=3D7 cap=3D991 } > [ 106.988842] CPU3 attaching sched-domain(s): > [ 106.989096] domain-0: span=3D2-3,5,7 level=3DMC > [ 106.989136] groups: 3:{ span=3D3 cap=3D154 }, 5:{ span=3D5 cap=3D495= }, 7:{ > span=3D7 cap=3D991 }, 2:{ span=3D2 cap=3D159 } > [ 106.989679] CPU5 attaching sched-domain(s): > [ 106.989692] domain-0: span=3D2-3,5,7 level=3DMC > [ 106.989773] groups: 5:{ span=3D5 cap=3D495 }, 7:{ span=3D7 cap=3D991= }, 2:{ > span=3D2 cap=3D159 }, 3:{ span=3D3 cap=3D154 } > [ 106.990466] CPU7 attaching sched-domain(s): > [ 106.990482] domain-0: span=3D2-3,5,7 level=3DMC > [ 106.990632] groups: 7:{ span=3D7 cap=3D991 }, 2:{ span=3D2 cap=3D159= }, 3:{ > span=3D3 cap=3D154 }, 5:{ span=3D5 cap=3D495 } > [ 106.997604] root domain span: 2-3,5,7 > [ 106.998267] CPU0 attaching sched-domain(s): > [ 106.998278] domain-0: span=3D0-1,4,6 level=3DMC > [ 106.998295] groups: 0:{ span=3D0 cap=3D159 }, 1:{ span=3D1 cap=3D160= }, 4:{ > span=3D4 cap=3D496 }, 6:{ span=3D6 cap=3D995 } > [ 106.998584] CPU1 attaching sched-domain(s): > [ 106.998592] domain-0: span=3D0-1,4,6 level=3DMC > [ 106.998604] groups: 1:{ span=3D1 cap=3D160 }, 4:{ span=3D4 cap=3D496= }, 6:{ > span=3D6 cap=3D995 }, 0:{ span=3D0 cap=3D159 } > [ 106.999477] CPU4 attaching sched-domain(s): > [ 106.999487] domain-0: span=3D0-1,4,6 level=3DMC > [ 106.999504] groups: 4:{ span=3D4 cap=3D496 }, 6:{ span=3D6 cap=3D995= }, 0:{ > span=3D0 cap=3D159 }, 1:{ span=3D1 cap=3D160 } > [ 107.000070] CPU6 attaching sched-domain(s): > [ 107.000082] domain-0: span=3D0-1,4,6 level=3DMC > [ 107.000095] groups: 6:{ span=3D6 cap=3D995 }, 0:{ span=3D0 cap=3D159= }, 1:{ > span=3D1 cap=3D160 }, 4:{ span=3D4 cap=3D496 } > [ 107.000721] root domain span: 0-1,4,6 > [ 107.001152] root_domain 2-3,5,7: pd6:{ cpus=3D6-7 nr_pstate=3D4 } pd4:= { > cpus=3D4-5 nr_pstate=3D4 } pd0:{ cpus=3D0-3 nr_pstate=3D4 } > [ 107.001869] root_domain 0-1,4,6: pd6:{ cpus=3D6-7 nr_pstate=3D4 } pd4:= { > cpus=3D4-5 nr_pstate=3D4 } pd0:{ cpus=3D0-3 nr_pstate=3D4 } > > [...]