[PATCH] riscv: mm: fix regression due to update_mmu_cache change
Sergey Matyukevich
geomatsi at gmail.com
Sun Jan 29 13:18:18 PST 2023
From: Sergey Matyukevich <sergey.matyukevich at syntacore.com>
This is a partial revert of the commit 4bd1d80efb5a ("riscv: mm: notify
remote harts about mmu cache updates"). Original commit included two
loosely related changes serving the same purpose of fixing stale TLB
entries causing user-space application crash:
- introduce deferred per-ASID TLB flush for CPUs not running the task
- switch to per-ASID TLB flush on all CPUs running the task in update_mmu_cache
According to report and discussion in [1], the second part caused a
regression on Renesas RZ/Five SoC. For now restore the old behavior
of the update_mmu_cache.
[1] https://lore.kernel.org/linux-riscv/20220829205219.283543-1-geomatsi@gmail.com/
Fixes: 4bd1d80efb5a ("riscv: mm: notify remote harts about mmu cache updates")
Reported-by: "Lad, Prabhakar" <prabhakar.csengg at gmail.com>
Signed-off-by: Sergey Matyukevich <sergey.matyukevich at syntacore.com>
---
arch/riscv/include/asm/pgtable.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 4eba9a98d0e3..4c3c130ee328 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -415,7 +415,7 @@ static inline void update_mmu_cache(struct vm_area_struct *vma,
* Relying on flush_tlb_fix_spurious_fault would suffice, but
* the extra traps reduce performance. So, eagerly SFENCE.VMA.
*/
- flush_tlb_page(vma, address);
+ local_flush_tlb_page(address);
}
#define __HAVE_ARCH_UPDATE_MMU_TLB
--
2.39.0
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