Re: [PATCH 2/4] xfs: restore allocation trylock iteration

["Darrick J. Wong" <djwong@kernel.org>]

On Wed, May 17, 2023 at 10:04:47AM +1000, Dave Chinner wrote:
> From: Dave Chinner <dchinner@redhat.com>
> 
> It was accidentally dropped when refactoring the allocation code,
> resulting in the AG iteration always doing blocking AG iteration.
> This results in a small performance regression for a specific fsmark
> test that runs more user data writer threads than there are AGs.
> 
> Reported-by: kernel test robot <oliver.sang@intel.com>
> Fixes: 2edf06a50f5b ("xfs: factor xfs_alloc_vextent_this_ag() for _iterate_ags()")
> Signed-off-by: Dave Chinner <dchinner@redhat.com>

Heh, this is exactly what I was thinking from that thread...

Reviewed-by: Darrick J. Wong <djwong@kernel.org>

--D

> ---
>  fs/xfs/libxfs/xfs_alloc.c | 13 +++++++------
>  1 file changed, 7 insertions(+), 6 deletions(-)
> 
> diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
> index fdfa08cbf4db..61eb65be17f3 100644
> --- a/fs/xfs/libxfs/xfs_alloc.c
> +++ b/fs/xfs/libxfs/xfs_alloc.c
> @@ -3187,7 +3187,8 @@ xfs_alloc_vextent_check_args(
>   */
>  static int
>  xfs_alloc_vextent_prepare_ag(
> -	struct xfs_alloc_arg	*args)
> +	struct xfs_alloc_arg	*args,
> +	uint32_t		flags)
>  {
>  	bool			need_pag = !args->pag;
>  	int			error;
> @@ -3196,7 +3197,7 @@ xfs_alloc_vextent_prepare_ag(
>  		args->pag = xfs_perag_get(args->mp, args->agno);
>  
>  	args->agbp = NULL;
> -	error = xfs_alloc_fix_freelist(args, 0);
> +	error = xfs_alloc_fix_freelist(args, flags);
>  	if (error) {
>  		trace_xfs_alloc_vextent_nofix(args);
>  		if (need_pag)
> @@ -3336,7 +3337,7 @@ xfs_alloc_vextent_this_ag(
>  		return error;
>  	}
>  
> -	error = xfs_alloc_vextent_prepare_ag(args);
> +	error = xfs_alloc_vextent_prepare_ag(args, 0);
>  	if (!error && args->agbp)
>  		error = xfs_alloc_ag_vextent_size(args);
>  
> @@ -3380,7 +3381,7 @@ xfs_alloc_vextent_iterate_ags(
>  	for_each_perag_wrap_range(mp, start_agno, restart_agno,
>  			mp->m_sb.sb_agcount, agno, args->pag) {
>  		args->agno = agno;
> -		error = xfs_alloc_vextent_prepare_ag(args);
> +		error = xfs_alloc_vextent_prepare_ag(args, flags);
>  		if (error)
>  			break;
>  		if (!args->agbp) {
> @@ -3546,7 +3547,7 @@ xfs_alloc_vextent_exact_bno(
>  		return error;
>  	}
>  
> -	error = xfs_alloc_vextent_prepare_ag(args);
> +	error = xfs_alloc_vextent_prepare_ag(args, 0);
>  	if (!error && args->agbp)
>  		error = xfs_alloc_ag_vextent_exact(args);
>  
> @@ -3587,7 +3588,7 @@ xfs_alloc_vextent_near_bno(
>  	if (needs_perag)
>  		args->pag = xfs_perag_grab(mp, args->agno);
>  
> -	error = xfs_alloc_vextent_prepare_ag(args);
> +	error = xfs_alloc_vextent_prepare_ag(args, 0);
>  	if (!error && args->agbp)
>  		error = xfs_alloc_ag_vextent_near(args);
>  
> -- 
> 2.40.1
>