Re: [PATCH v2 03/12] md/raid5: Move stripe_add_to_batch_list() call out of add_stripe_bio()

[Guoqing Jiang]

On 4/21/22 3:54 AM, Logan Gunthorpe wrote:
> stripe_add_to_batch_list() is better done in the loop in make_request
> instead of inside add_stripe_bio(). This is clearer and allows for
> storing the batch_head state outside the loop in a subsequent patch.
>
> The call to add_stripe_bio() in retry_aligned_read() is for read
> and batching only applies to write. So it's impossible for batching
> to happen at that call site.
>
> No functional changes intended.
>
> Signed-off-by: Logan Gunthorpe<logang@xxxxxxxxxxxx>
> Reviewed-by: Christoph Hellwig<hch@xxxxxx>
> ---
>   drivers/md/raid5.c | 5 +++--
>   1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
> index cda6857e6207..8e1ece5ce984 100644
> --- a/drivers/md/raid5.c
> +++ b/drivers/md/raid5.c
> @@ -3534,8 +3534,6 @@ static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx,
>   	}
>   	spin_unlock_irq(&sh->stripe_lock);
>   
> -	if (stripe_can_batch(sh))
> -		stripe_add_to_batch_list(conf, sh);
>   	return 1;
>   
>    overlap:
> @@ -5955,6 +5953,9 @@ static bool raid5_make_request(struct mddev *mddev, struct bio * bi)
>   			goto retry;
>   		}
>   
> +		if (stripe_can_batch(sh))
> +			stripe_add_to_batch_list(conf, sh);
> +
>   		if (do_flush) {
>   			set_bit(STRIPE_R5C_PREFLUSH, &sh->state);
>   			/* we only need flush for one stripe */


Reviewed-by: Guoqing Jiang <guoqing.jiang@xxxxxxxxx>

Thanks,
Guoqing