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Date: Wed, 07 Feb 2024 11:35:12 -0800 (PST)
Subject:     Re: [PATCH -fixes] riscv: Fix arch_tlbbatch_flush() by clearing the batch cpumask
In-Reply-To: <a21e4253-9ef6-4c44-917c-02742440d192@sifive.com>
CC: alexghiti@rivosinc.com, Paul Walmsley <paul.walmsley@sifive.com>,
  aou@eecs.berkeley.edu, jszhang@kernel.org, linux-riscv@lists.infradead.org,
  linux-kernel@vger.kernel.org
From: Palmer Dabbelt <palmer@dabbelt.com>
To: samuel.holland@sifive.com
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On Wed, 07 Feb 2024 11:23:55 PST (-0800), samuel.holland@sifive.com wrote:
> Hi Alex,
>
> On 2024-01-30 5:55 AM, Alexandre Ghiti wrote:
>> We must clear the cpumask once we have flushed the batch, otherwise cpus
>> get accumulated and we end sending IPIs to more cpus than needed.
>>
>> Fixes: 54d7431af73e ("riscv: Add support for BATCHED_UNMAP_TLB_FLUSH")
>> Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
>> ---
>>  arch/riscv/mm/tlbflush.c | 1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff --git a/arch/riscv/mm/tlbflush.c b/arch/riscv/mm/tlbflush.c
>> index 99c3e037f127..c8efc3f87a0f 100644
>> --- a/arch/riscv/mm/tlbflush.c
>> +++ b/arch/riscv/mm/tlbflush.c
>> @@ -240,4 +240,5 @@ void arch_tlbbatch_flush(struct arch_tlbflush_unmap_batch *batch)
>>  {
>>  	__flush_tlb_range(NULL, &batch->cpumask,
>>  			  0, FLUSH_TLB_MAX_SIZE, PAGE_SIZE);
>> +	cpumask_clear(&batch->cpumask);
>>  }
>
> This patch doesn't apply to fixes -- it looks like it was based on "riscv: Call
> secondary mmu notifier when flushing the tlb"[1], which has not been merged and
> would go in for-next anyway. Otherwise:
>
> Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
>
> [1]: https://lore.kernel.org/all/20240124080325.2324462-1-alexghiti@rivosinc.com/

Ya and for some reason it trips up "patch -p1", which applies it to some 
other function.  I just merged it manually a few minutes ago and it's in 
the tester...