On 16/10/2024 15:54, Jeff Layton wrote: > On Wed, 2024-10-16 at 10:47 -0400, Chuck Lever wrote: >> On Wed, Oct 16, 2024 at 03:42:12PM +0100, Ryan Roberts wrote: >>> + 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@xxxxxxx/ >>> >>> >>> 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@xxxxxxx> >>>> --- >>>> >>>> ***NOTE*** >>>> Any confused maintainers may want to read the cover note here for context: >>>> https://lore.kernel.org/all/20241014105514.3206191-1-ryan.roberts@xxxxxxx/ >>>> >>>> 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) >> >> There is already a "MAX" in the name, so adding this new macro seems >> superfluous to me. Can we get away with simply updating the >> "RPCSVC_MAXPAGES" macro, instead of adding this new one? >> > > +1 that was my thinking too. This is mostly just used to size arrays, > so we might as well just change the existing macro. I agree, its not the prettiest. I was (incorrectly) assuming you would want to continue to limit the number of actual pages at runtime based on the in-use page size. That said, looking again at the code, RPCSVC_MAXPAGES never actually gets used to dynamically allocate any memory. So I propose to just do the following: #define RPCSVC_MAXPAGES ((RPCSVC_MAXPAYLOAD+PAGE_SIZE_MIN-1)/ PAGE_SIZE_MIN + 2 + 1) That will be 259 in practice (assuming PAGE_SIZE_MIN=4K). > > With 64k pages we probably wouldn't need arrays as long as these will > be. Fixing those array sizes to be settable at runtime though is not a > trivial project though. Indeed. Hopefully the above is sufficient. Thanks for the review! Ryan > >> >>>> /* >>>> * 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) >>> >> >
