riscv: Only flush the mm icache when setting an exec pte
We used to emit a flush_icache_all() whenever a dirty executable
mapping is set in the page table but we can instead call
flush_icache_mm() which will only send IPIs to cores that currently run
this mm and add a deferred icache flush to the others.
The number of calls to sbi_remote_fence_i() (tested without IPI
support):
With a simple buildroot rootfs:
* Before: ~5k
* After : 4 (!)
Tested on HW, the boot to login is ~4.5% faster.
With an ubuntu rootfs:
* Before: ~24k
* After : ~13k
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Link: https://lore.kernel.org/r/20240202124711.256146-1-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
3 files changed
