From: Drew Fustini <fustini@kernel.org>
To: yunhui cui <cuiyunhui@bytedance.com>
Cc: "Paul Walmsley" <pjw@kernel.org>,
"Palmer Dabbelt" <palmer@dabbelt.com>,
"Albert Ou" <aou@eecs.berkeley.edu>,
"Alexandre Ghiti" <alex@ghiti.fr>,
"Radim Krčmář" <rkrcmar@ventanamicro.com>,
"Samuel Holland" <samuel.holland@sifive.com>,
"Adrien Ricciardi" <aricciardi@baylibre.com>,
"Nicolas Pitre" <npitre@baylibre.com>,
"Kornel Dulęba" <mindal@semihalf.com>,
"Atish Patra" <atish.patra@linux.dev>,
"Atish Kumar Patra" <atishp@rivosinc.com>,
"Vasudevan Srinivasan" <vasu@rivosinc.com>,
"Ved Shanbhogue" <ved@rivosinc.com>,
"Chen Pei" <cp0613@linux.alibaba.com>,
"Liu Zhiwei" <zhiwei_liu@linux.alibaba.com>,
"Weiwei Li" <liwei1518@gmail.com>,
guo.wenjia23@zte.com.cn, liu.qingtao2@zte.com.cn,
"Conor Dooley" <conor+dt@kernel.org>,
"Krzysztof Kozlowski" <krzk+dt@kernel.org>,
"Rob Herring" <robh+dt@kernel.org>,
"Reinette Chatre" <reinette.chatre@intel.com>,
"Tony Luck" <tony.luck@intel.com>,
"Babu Moger" <babu.moger@amd.com>,
"Peter Newman" <peternewman@google.com>,
"Fenghua Yu" <fenghua.yu@intel.com>,
"James Morse" <james.morse@arm.com>,
"Ben Horgan" <ben.horgan@arm.com>,
"Dave Martin" <Dave.Martin@arm.com>,
devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-riscv@lists.infradead.org, x86@kernel.org
Subject: Re: [External] [PATCH RFC 08/19] RISC-V: QoS: add resctrl interface for CBQRI controllers
Date: Tue, 27 Jan 2026 14:10:22 -0800 [thread overview]
Message-ID: <aXk3zq26cU8r/COG@x1> (raw)
In-Reply-To: <aXfWVPg7YTToDKcQ@x1>
On Mon, Jan 26, 2026 at 01:02:12PM -0800, Drew Fustini wrote:
> On Mon, Jan 26, 2026 at 09:01:30PM +0800, yunhui cui wrote:
> > Hi Drew,
> >
> > On Tue, Jan 20, 2026 at 12:15 PM Drew Fustini <fustini@kernel.org> wrote:
> > >
> > > Add interface for CBQRI controller drivers to make use of the resctrl
> > > filesystem.
> > >
> > > Co-developed-by: Adrien Ricciardi <aricciardi@baylibre.com>
> > > Signed-off-by: Adrien Ricciardi <aricciardi@baylibre.com>
> > > Signed-off-by: Drew Fustini <fustini@kernel.org>
> > > ---
> > > arch/riscv/kernel/qos/qos_resctrl.c | 1191 +++++++++++++++++++++++++++++++++++
> > > 1 file changed, 1191 insertions(+)
> > >
> > > diff --git a/arch/riscv/kernel/qos/qos_resctrl.c b/arch/riscv/kernel/qos/qos_resctrl.c
> > > new file mode 100644
> > > index 000000000000..5e3a65342e9b
> > > --- /dev/null
> > > +++ b/arch/riscv/kernel/qos/qos_resctrl.c
[..]
> > > + case RDT_RESOURCE_MBA:
> > > + /* Capacity read limit operation for RCID (closid) */
> > > + err = cbqri_bc_alloc_op(ctrl, CBQRI_CC_ALLOC_CTL_OP_READ_LIMIT, closid);
> > > + if (err < 0) {
> > > + pr_err("%s(): operation failed: err = %d", __func__, err);
> > > + return -EIO;
> > > + }
> > > +
> > > + hw_dom->ctrl_val[closid] = cbqri_get_rbwb(ctrl);
> > > +
> > > + /* Convert from bandwidth blocks to percent */
> > > + rbwb = hw_dom->ctrl_val[closid];
> > > + rbwb *= 100;
> > > + percent = rbwb / ctrl->bc.nbwblks;
> > > + if (rbwb % ctrl->bc.nbwblks)
> > > + percent++;
> >
> > set: 10, get 11 ?
>
> The intention was to handle rounding up but I can drop this increment.
Actually, this increment of one is necessary. Without it, the default
value of 80% will be displayed as 79%. And writing a value like 55% will
result in 54%.
# mount -t resctrl resctrl /sys/fs/resctrl
# cd /sys/fs/resctrl
# cat schemata
MB:0=79;1=79;2=79
L2:4=fff;5=fff
L3:3=ffff
# echo 'MB:2=55' > schemata
# cat schemata
MB:0=79;1=79;2=54
L2:4=fff;5=fff
L3:3=ffff
# echo 'MB:2=80' > schemata
# cat schemata
MB:0=79;1=79;2=79
L2:4=fff;5=fff
L3:3=ffff
Thanks,
Drew
next prev parent reply other threads:[~2026-01-27 22:10 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-20 4:14 [PATCH RFC 00/19] RISC-V: QoS: add CBQRI resctrl interface Drew Fustini
2026-01-20 4:14 ` [PATCH RFC 01/19] dt-bindings: riscv: Add Ssqosid extension description Drew Fustini
2026-01-20 4:14 ` [PATCH RFC 02/19] RISC-V: Detect the Ssqosid extension Drew Fustini
2026-01-20 4:14 ` [PATCH RFC 03/19] RISC-V: Add support for srmcfg CSR from Ssqosid ext Drew Fustini
2026-01-20 4:14 ` [PATCH RFC 04/19] RISC-V: QoS: define properties of CBQRI controllers Drew Fustini
2026-01-20 4:14 ` [PATCH RFC 05/19] RISC-V: QoS: define CBQRI capacity and bandwidth capabilities Drew Fustini
2026-01-20 4:14 ` [PATCH RFC 06/19] RISC-V: QoS: define CBQRI resctrl resources and domains Drew Fustini
2026-01-20 4:14 ` [PATCH RFC 07/19] RISC-V: QoS: define prototypes for resctrl interface Drew Fustini
2026-01-20 4:14 ` [PATCH RFC 08/19] RISC-V: QoS: add resctrl interface for CBQRI controllers Drew Fustini
2026-01-26 13:01 ` [External] " yunhui cui
2026-01-26 21:02 ` Drew Fustini
2026-01-27 22:10 ` Drew Fustini [this message]
2026-03-26 11:05 ` guo.wenjia23
2026-01-20 4:14 ` [PATCH RFC 09/19] RISC-V: QoS: expose implementation to resctrl Drew Fustini
2026-01-20 4:14 ` [PATCH RFC 10/19] RISC-V: QoS: add late_initcall to setup resctrl interface Drew Fustini
2026-01-20 4:14 ` [PATCH RFC 11/19] RISC-V: QoS: add to build when CONFIG_RISCV_ISA_SSQOSID set Drew Fustini
2026-01-20 4:14 ` [PATCH RFC 12/19] RISC-V: QoS: make CONFIG_RISCV_ISA_SSQOSID select resctrl Drew Fustini
2026-01-20 4:14 ` [PATCH RFC 13/19] dt-bindings: riscv: add riscv,cbqri bindings Drew Fustini
2026-01-20 4:14 ` [PATCH NFU RFC 14/19] resctrl: riscv: add CBQRI cache controller driver Drew Fustini
2026-01-20 4:14 ` [PATCH NFU RFC 15/19] resctrl: riscv: add CBQRI bandwidth " Drew Fustini
2026-01-20 4:14 ` [PATCH NFU RFC 16/19] resctrl: riscv: build CBQRI drivers Drew Fustini
2026-01-20 4:14 ` [PATCH NFU RFC 17/19] riscv: dts: qemu: add dump from virt machine Drew Fustini
2026-01-20 4:14 ` [PATCH NFU RFC 18/19] riscv: dts: qemu: add CBQRI controller nodes Drew Fustini
2026-01-20 4:14 ` [PATCH NFU RFC 19/19] riscv: dts: build qemu dtb for CONFIG_ARCH_VIRT Drew Fustini
2026-01-22 22:31 ` [PATCH RFC 00/19] RISC-V: QoS: add CBQRI resctrl interface Reinette Chatre
2026-01-24 18:00 ` Drew Fustini
2026-01-26 13:14 ` [External] " yunhui cui
2026-01-26 20:11 ` Drew Fustini
2026-01-27 2:33 ` yunhui cui
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