kernel-hacking-2024-linux-s.../Documentation/arch
Palmer Dabbelt 52420e483d
RISC-V: Provide the frequency of time CSR via hwprobe
The RISC-V architecture makes a real time counter CSR (via RDTIME
instruction) available for applications in U-mode but there is no
architected mechanism for an application to discover the frequency
the counter is running at. Some applications (e.g., DPDK) use the
time counter for basic performance analysis as well as fine grained
time-keeping.

Add support to the hwprobe system call to export the time CSR
frequency to code running in U-mode.

Signed-off-by: Yunhui Cui <cuiyunhui@bytedance.com>
Reviewed-by: Evan Green <evan@rivosinc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Acked-by: Punit Agrawal <punit.agrawal@bytedance.com>
Link: https://lore.kernel.org/r/20240702033731.71955-2-cuiyunhui@bytedance.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-26 05:50:51 -07:00
..
arc
arm
arm64 Merge branch 'for-next/vcpu-hotplug' into for-next/core 2024-07-11 19:10:02 +01:00
loongarch
m68k Docs: typos/spelling 2024-05-02 10:02:29 -06:00
mips
nios2
openrisc
parisc
powerpc Merge branch 'topic/ppc-kvm' into next 2024-07-18 14:32:46 +10:00
riscv RISC-V: Provide the frequency of time CSR via hwprobe 2024-07-26 05:50:51 -07:00
s390 docs: Update s390 vfio-ap doc for ap_config sysfs attribute 2024-04-22 12:49:18 +02:00
sh
sparc Docs: typos/spelling 2024-05-02 10:02:29 -06:00
x86 Nothing hugely exciting happening in the documentation tree this time 2024-07-18 15:54:16 -07:00
xtensa
index.rst