Raise CONFIG_NR_CPUS
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux-riscv (Ubuntu) |
Fix Released
|
Undecided
|
Emil Renner Berthing |
Bug Description
[Impact]
* Currently our riscv64 kernels don't support more than 8 CPUs.
* The QEMU 7.0 virt machine supports up to 512 virtual CPUs.
* Raising CONFIG_NR_CPUS to the maximum of 32 allows us to use
more of them.
[Test Plan]
* Run riscv64 Ubuntu in a QEMU virt instance with more than 8
virtual CPUs and see that only 8 of them are used.
* After raising CONFIG_NR_CPUS up to 32 of them should be used.
[Where problems could occur]
* This will allocate slightly more RAM which might hurt very small
machines.
[Other Info]
* Original bug description:
The QEMU 7.0 virt machine offers up to 32 virtual harts. This matches the number of hardware threads on a typical desktop CPU (AMD Ryzen 5950X). Our Linux kernel should support this number of harts.
Best regards
Heinrich
CVE References
Changed in linux-riscv (Ubuntu): | |
assignee: | nobody → Emil Renner Berthing (esmil) |
description: | updated |
description: | updated |
description: | updated |
description: | updated |
description: | updated |
The following patch sets reasonable values for CONFIG_NR_CPUS on RISC-V:
[PATCH v3] RISC-V: Increase range and default value of NR_CPUS
https://<email address hidden>/