Re: [PATCH 12/13] riscv/irq: use seq_put_decimal_ull_width() for decimal values

["David Wang" <00107082@163.com>]

Hi, 

Thanks for the test and  review, and sorry for not giving  more attentions to alignment issues when made the patch.
But if alignment should not be changed, simply appending a [space] is not enough:  the patch change
'%10u[space]" to "[space]%10u",   one [space] is moved from tail to the front,  and to restore to its original state
, one [space] should be removed from front.  and It would make the code  ugly and unpleasant  to remove a [space]
from this line 
        seq_printf(p, "%*s%u:%s", prec - 1, "IPI", i, prec >= 4 ? " " : "");
( or make changes to seq_put_decimal_ull_width)


Kind of think that it does not worth the effort if  code changes are way too unpleasant....


Thanks
David
 

At 2025-02-25 23:10:26, "Alexandre Ghiti" <alex@ghiti.fr> wrote:
>Hi David,
>
>On 08/11/2024 17:25, David Wang wrote:
>> Performance improvement for reading /proc/interrupts on arch riscv
>>
>> Signed-off-by: David Wang <00107082@163.com>
>> ---
>>   arch/riscv/kernel/smp.c | 3 ++-
>>   1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/riscv/kernel/smp.c b/arch/riscv/kernel/smp.c
>> index c180a647a30e..f1e9c3db094c 100644
>> --- a/arch/riscv/kernel/smp.c
>> +++ b/arch/riscv/kernel/smp.c
>> @@ -226,7 +226,8 @@ void show_ipi_stats(struct seq_file *p, int prec)
>>   		seq_printf(p, "%*s%u:%s", prec - 1, "IPI", i,
>>   			   prec >= 4 ? " " : "");
>>   		for_each_online_cpu(cpu)
>> -			seq_printf(p, "%10u ", irq_desc_kstat_cpu(ipi_desc[i], cpu));
>> +			seq_put_decimal_ull_width(p, " ",
>> +						  irq_desc_kstat_cpu(ipi_desc[i], cpu), 10);
>>   		seq_printf(p, " %s\n", ipi_names[i]);
>>   	}
>>   }
>
>
>Very late answer sorry!
>
>I don't have the same output before and after your patch because 
>seq_put_decimal_ull_width() second argument is placed *before* the 
>number, not after as it was before.
>
>The following diff fixes the issue:
>
>diff --git a/arch/riscv/kernel/smp.c b/arch/riscv/kernel/smp.c index 
>f1e9c3db094c3..4b80ee4e5b2c0 100644 --- a/arch/riscv/kernel/smp.c +++ 
>b/arch/riscv/kernel/smp.c @@ -225,9 +225,11 @@ void 
>show_ipi_stats(struct seq_file *p, int prec) for (i = 0; i < IPI_MAX; 
>i++) { seq_printf(p, "%*s%u:%s", prec - 1, "IPI", i, prec >= 4 ? " " : 
>""); - for_each_online_cpu(cpu) - seq_put_decimal_ull_width(p, " ", + 
>for_each_online_cpu(cpu) { + seq_put_decimal_ull_width(p, NULL, 
>irq_desc_kstat_cpu(ipi_desc[i], cpu), 10); + seq_putc(p, ' '); + } 
>seq_printf(p, " %s\n", ipi_names[i]); } }
>
>Will you respin a new version?
>
>Thanks,
>
>Alex