From: Chuck Lever <chuck.lever@xxxxxxxxxx> In order to make RPCSVC_MAXPAYLOAD larger (or variable in size), we need to do something clever with the payload arrays embedded in struct svc_rqst and elsewhere. My preference is to keep these arrays allocated all the time because allocating them on demand increases the risk of a memory allocation failure during a large I/O. This is a quick-and-dirty approach that might be replaced once NFSD is converted to use large folios. The downside of this design choice is that it pins a few pages per NFSD thread (and that's the current situation already). But note that because RPCSVC_MAXPAGES is 259, each array is just over a page in size, making the allocation waste quite a bit of memory beyond the end of the array due to power-of-2 allocator round up. This gets worse as the MAXPAGES value is doubled or quadrupled. This series also addresses similar issues in the socket and RDMA transports. Chuck Lever (9): sunrpc: Remove backchannel check in svc_init_buffer() sunrpc: Add a helper to derive maxpages from sv_max_mesg sunrpc: Replace the rq_pages array with dynamically-allocated memory sunrpc: Replace the rq_vec array with dynamically-allocated memory sunrpc: Replace the rq_bvec array with dynamically-allocated memory sunrpc: Adjust size of socket's receive page array dynamically svcrdma: Adjust the number of RDMA contexts per transport svcrdma: Adjust the number of entries in svc_rdma_recv_ctxt::rc_pages svcrdma: Adjust the number of entries in svc_rdma_send_ctxt::sc_pages fs/nfsd/nfs4proc.c | 1 - fs/nfsd/vfs.c | 2 +- include/linux/sunrpc/svc.h | 19 +++++++-- include/linux/sunrpc/svc_rdma.h | 6 ++- include/linux/sunrpc/svcsock.h | 4 +- net/sunrpc/svc.c | 51 +++++++++++++++--------- net/sunrpc/svc_xprt.c | 10 +---- net/sunrpc/svcsock.c | 15 ++++--- net/sunrpc/xprtrdma/svc_rdma_recvfrom.c | 8 +++- net/sunrpc/xprtrdma/svc_rdma_rw.c | 2 +- net/sunrpc/xprtrdma/svc_rdma_sendto.c | 16 ++++++-- net/sunrpc/xprtrdma/svc_rdma_transport.c | 2 +- 12 files changed, 88 insertions(+), 48 deletions(-) -- 2.49.0 Chuck Lever (10): sunrpc: Remove backchannel check in svc_init_buffer() sunrpc: Add a helper to derive maxpages from sv_max_mesg sunrpc: Replace the rq_pages array with dynamically-allocated memory sunrpc: Replace the rq_vec array with dynamically-allocated memory sunrpc: Replace the rq_bvec array with dynamically-allocated memory sunrpc: Adjust size of socket's receive page array dynamically svcrdma: Adjust the number of RDMA contexts per transport svcrdma: Adjust the number of entries in svc_rdma_recv_ctxt::rc_pages svcrdma: Adjust the number of entries in svc_rdma_send_ctxt::sc_pages sunrpc: Remove the RPCSVC_MAXPAGES macro fs/nfsd/nfs4proc.c | 1 - fs/nfsd/vfs.c | 2 +- include/linux/sunrpc/svc.h | 31 +++++++++----- include/linux/sunrpc/svc_rdma.h | 6 ++- include/linux/sunrpc/svcsock.h | 4 +- net/sunrpc/svc.c | 51 +++++++++++++++--------- net/sunrpc/svc_xprt.c | 10 +---- net/sunrpc/svcsock.c | 15 ++++--- net/sunrpc/xprtrdma/svc_rdma_recvfrom.c | 8 +++- net/sunrpc/xprtrdma/svc_rdma_rw.c | 2 +- net/sunrpc/xprtrdma/svc_rdma_sendto.c | 16 ++++++-- net/sunrpc/xprtrdma/svc_rdma_transport.c | 2 +- 12 files changed, 93 insertions(+), 55 deletions(-) -- 2.49.0
