Re: [RFC PATCH v1 21/57] sunrpc: Remove PAGE_SIZE compile-time constant assumption

Ryan Roberts
2024-10-16T14:48:45Z

+ Chuck Lever, Jeff Layton

This was a rather tricky series to get the recipients correct for and my script
did not realize that "supporter" was a pseudonym for "maintainer" so you were
missed off the original post. Appologies!

More context in cover letter:
https://lore.kernel.org/all/20241014105514.3206191-1-ryan.roberts@arm.com/

On 14/10/2024 11:58, Ryan Roberts wrote:
> To prepare for supporting boot-time page size selection, refactor code
> to remove assumptions about PAGE_SIZE being compile-time constant. Code
> intended to be equivalent when compile-time page size is active.
>
> Updated array sizes in various structs to contain enough entries for the
> smallest supported page size.
>
> Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
> ---
>
> ***NOTE***
> Any confused maintainers may want to read the cover note here for context:
> https://lore.kernel.org/all/20241014105514.3206191-1-ryan.roberts@arm.com/
>
> include/linux/sunrpc/svc.h | 8 +++++---
> include/linux/sunrpc/svc_rdma.h | 4 ++--
> include/linux/sunrpc/svcsock.h | 2 +-
> 3 files changed, 8 insertions(+), 6 deletions(-)
>
> diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h
> index a7d0406b9ef59..dda44018b8f36 100644
> --- a/include/linux/sunrpc/svc.h
> +++ b/include/linux/sunrpc/svc.h
> @@ -160,6 +160,8 @@ extern u32 svc_max_payload(const struct svc_rqst *rqstp);
> */
> #define RPCSVC_MAXPAGES ((RPCSVC_MAXPAYLOAD+PAGE_SIZE-1)/PAGE_SIZE \
> + 2 + 1)
> +#define RPCSVC_MAXPAGES_MAX ((RPCSVC_MAXPAYLOAD+PAGE_SIZE_MIN-1)/PAGE_SIZE_MIN \
> + + 2 + 1)
>
> /*
> * The context of a single thread, including the request currently being
> @@ -190,14 +192,14 @@ struct svc_rqst {
> struct xdr_stream rq_res_stream;
> struct page *rq_scratch_page;
> struct xdr_buf rq_res;
> - struct page *rq_pages[RPCSVC_MAXPAGES + 1];
> + struct page *rq_pages[RPCSVC_MAXPAGES_MAX + 1];
> struct page * *rq_respages; /* points into rq_pages */
> struct page * *rq_next_page; /* next reply page to use */
> struct page * *rq_page_end; /* one past the last page */
>
> struct folio_batch rq_fbatch;
> - struct kvec rq_vec[RPCSVC_MAXPAGES]; /* generally useful.. */
> - struct bio_vec rq_bvec[RPCSVC_MAXPAGES];
> + struct kvec rq_vec[RPCSVC_MAXPAGES_MAX]; /* generally useful.. */
> + struct bio_vec rq_bvec[RPCSVC_MAXPAGES_MAX];
>
> __be32 rq_xid; /* transmission id */
> u32 rq_prog; /* program number */
> diff --git a/include/linux/sunrpc/svc_rdma.h b/include/linux/sunrpc/svc_rdma.h
> index d33bab33099ab..7c6441e8d6f7a 100644
> --- a/include/linux/sunrpc/svc_rdma.h
> +++ b/include/linux/sunrpc/svc_rdma.h
> @@ -200,7 +200,7 @@ struct svc_rdma_recv_ctxt {
> struct svc_rdma_pcl rc_reply_pcl;
>
> unsigned int rc_page_count;
> - struct page *rc_pages[RPCSVC_MAXPAGES];
> + struct page *rc_pages[RPCSVC_MAXPAGES_MAX];
> };
>
> /*
> @@ -242,7 +242,7 @@ struct svc_rdma_send_ctxt {
> void *sc_xprt_buf;
> int sc_page_count;
> int sc_cur_sge_no;
> - struct page *sc_pages[RPCSVC_MAXPAGES];
> + struct page *sc_pages[RPCSVC_MAXPAGES_MAX];
> struct ib_sge sc_sges[];
> };
>
> diff --git a/include/linux/sunrpc/svcsock.h b/include/linux/sunrpc/svcsock.h
> index 7c78ec6356b92..6c6bcc82685a3 100644
> --- a/include/linux/sunrpc/svcsock.h
> +++ b/include/linux/sunrpc/svcsock.h
> @@ -40,7 +40,7 @@ struct svc_sock {
>
> struct completion sk_handshake_done;
>
> - struct page * sk_pages[RPCSVC_MAXPAGES]; /* received data */
> + struct page * sk_pages[RPCSVC_MAXPAGES_MAX]; /* received data */
> };
>
> static inline u32 svc_sock_reclen(struct svc_sock *svsk)