[PATCH] erofs: allocate extra bvec pages from reserved buffer pool first by default

[Gao Xiang]

Hi Chunhai,

On 2024/8/13 18:27, Chunhai Guo wrote:
> As the extra bvec pages are allocated and freed in a short time, it can

It'd be better to just simplify the subject
erofs: allocate bvpages from reserved buffer pool first

> reduce the page allocation time by first allocating pages from the
> reserved buffer pool [1].
> 
> [1] The reserved buffer pool and its benefits are detailed in

Although I can imagine it could have some benefits, but if it's
possible, could you give some real numbers for this commit (assume
that it's not hard) so that we could record them in the commit
message for other reference?

> commit 0f6273ab4637 ("erofs: add a reserved buffer pool for lz4
> decompression").
> 
> Signed-off-by: Chunhai Guo <guochunhai at vivo.com>

The patch itself looks good to me tho.

Thanks,
Gao Xiang

> ---
>   fs/erofs/zdata.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
> index b979529be5ed..428ab617e0e4 100644
> --- a/fs/erofs/zdata.c
> +++ b/fs/erofs/zdata.c
> @@ -232,7 +232,8 @@ static int z_erofs_bvec_enqueue(struct z_erofs_bvec_iter *iter,
>   		struct page *nextpage = *candidate_bvpage;
>   
>   		if (!nextpage) {
> -			nextpage = erofs_allocpage(pagepool, GFP_KERNEL);
> +			nextpage = __erofs_allocpage(pagepool, GFP_KERNEL,
> +					true);
>   			if (!nextpage)
>   				return -ENOMEM;
>   			set_page_private(nextpage, Z_EROFS_SHORTLIVED_PAGE);