It is useless to issue remote fences if there is a single core
available. It becomes a bottleneck for sbi based rfences where
we will be making those ECALLs for no reason. Early code patching
because of static calls end up in this path.
Signed-off-by: Atish Patra <atishp@xxxxxxxxxxxx>
---
arch/riscv/mm/cacheflush.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/riscv/mm/cacheflush.c b/arch/riscv/mm/cacheflush.c
index f10cb47eac3a..7fafc8c26505 100644
--- a/arch/riscv/mm/cacheflush.c
+++ b/arch/riscv/mm/cacheflush.c
@@ -19,6 +19,10 @@ void flush_icache_all(void)
{
local_flush_icache_all();
+ /* No need to issue remote fence if only 1 cpu is online */
+ if (num_online_cpus() == 1)
+ return;
+
if (IS_ENABLED(CONFIG_RISCV_SBI) && !riscv_use_ipi_for_rfence())
sbi_remote_fence_i(NULL);
else
--
2.34.1
