From 01261e24cfab69c65043e1e61168348ae23a64c2 Mon Sep 17 00:00:00 2001
From: Alexandre Ghiti <alexghiti@rivosinc.com>
Date: Fri, 2 Feb 2024 13:47:11 +0100
Subject: 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>
---
arch/riscv/mm/cacheflush.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
(limited to 'arch/riscv/mm/cacheflush.c')
diff --git a/arch/riscv/mm/cacheflush.c b/arch/riscv/mm/cacheflush.c
index 55a34f2020a8..bc61ee5975e4 100644
--- a/arch/riscv/mm/cacheflush.c
+++ b/arch/riscv/mm/cacheflush.c
@@ -82,12 +82,12 @@ void flush_icache_mm(struct mm_struct *mm, bool local)
#endif /* CONFIG_SMP */
#ifdef CONFIG_MMU
-void flush_icache_pte(pte_t pte)
+void flush_icache_pte(struct mm_struct *mm, pte_t pte)
{
struct folio *folio = page_folio(pte_page(pte));
if (!test_bit(PG_dcache_clean, &folio->flags)) {
- flush_icache_all();
+ flush_icache_mm(mm, false);
set_bit(PG_dcache_clean, &folio->flags);
}
}
--
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