kernel/linux.git/include/linux/sunrpc/svc.h, branch v7.0-rc7

sunrpc: allow svc_recv() to return -ETIMEDOUT and -EBUSY

2026-01-28T15:15:42+00:00

To dynamically adjust the thread count, nfsd requires some information about how busy things are. Change svc_recv() to take a timeout value, and then allow the wait for work to time out if it's set. If a timeout is not defined, then the schedule will be set to MAX_SCHEDULE_TIMEOUT. If the task waits for the full timeout, then have it return -ETIMEDOUT to the caller. If it wakes up, finds that there is more work and that no threads are available, then attempt to set SP_TASK_STARTING. If wasn't already set, have the task return -EBUSY to cue to the caller that the service could use more threads. Signed-off-by: Jeff Layton Signed-off-by: Chuck Lever

sunrpc: split new thread creation into a separate function

2026-01-28T15:15:42+00:00

Break out the part of svc_start_kthreads() that creates a thread into svc_new_thread(), as a new exported helper function. Signed-off-by: Jeff Layton Signed-off-by: Chuck Lever

sunrpc: introduce the concept of a minimum number of threads per pool

2026-01-28T15:15:42+00:00

Add a new pool->sp_nrthrmin field to track the minimum number of threads in a pool. Add min_threads parameters to both svc_set_num_threads() and svc_set_pool_threads(). If min_threads is non-zero and less than the max, svc_set_num_threads() will ensure that the number of running threads is between the min and the max. If the min is 0 or greater than the max, then it is ignored, and the maximum number of threads will be started, and never spun down. For now, the min_threads is always 0, but a later patch will pass the proper value through from nfsd. Signed-off-by: Jeff Layton Signed-off-by: Chuck Lever

sunrpc: track the max number of requested threads in a pool

2026-01-28T15:15:42+00:00

The kernel currently tracks the number of threads running in a pool in the "sp_nrthreads" field. In the future, where threads are dynamically spun up and down, it'll be necessary to keep track of the maximum number of requested threads separately from the actual number running. Add a pool->sp_nrthrmax parameter to track this. When userland changes the number of threads in a pool, update that value accordingly. Signed-off-by: Jeff Layton Signed-off-by: Chuck Lever

sunrpc: split svc_set_num_threads() into two functions

2026-01-28T15:15:42+00:00

svc_set_num_threads() will set the number of running threads for a given pool. If the pool argument is set to NULL however, it will distribute the threads among all of the pools evenly. These divergent codepaths complicate the move to dynamic threading. Simplify the API by splitting these two cases into different helpers: Add a new svc_set_pool_threads() function that sets the number of threads in a single, given pool. Modify svc_set_num_threads() to distribute the threads evenly between all of the pools and then call svc_set_pool_threads() for each. Signed-off-by: Jeff Layton Signed-off-by: Chuck Lever

SUNRPC: Update svcxdr_init_decode() to call xdr_set_scratch_folio()

2025-09-23T17:29:50+00:00

The only snag here is that __folio_alloc_node() doesn't handle NUMA_NO_NODE, so I also need to update svc_pool_map_get_node() to return numa_mem_id() instead. I arrived at this approach by looking at what other users of __folio_alloc_node() do for this case. Signed-off-by: Anna Schumaker

sunrpc: rearrange struct svc_rqst for fewer cachelines

2025-07-14T16:46:49+00:00

This shrinks the struct by 4 bytes, but also takes it from 19 to 18 cachelines on x86_64. Signed-off-by: Jeff Layton Signed-off-by: Chuck Lever

SUNRPC: Bump the maximum payload size for the server

2025-05-15T20:16:28+00:00

Increase the maximum server-side RPC payload to 4MB. The default remains at 1MB. An API to adjust the operational maximum was added in 2006 by commit 596bbe53eb3a ("[PATCH] knfsd: Allow max size of NFSd payload to be configured"). To adjust the operational maximum using this API, shut down the NFS server. Then echo a new value into: /proc/fs/nfsd/max_block_size And restart the NFS server. Reviewed-by: Jeff Layton Reviewed-by: NeilBrown Signed-off-by: Chuck Lever

sunrpc: Remove the RPCSVC_MAXPAGES macro

2025-05-15T20:16:27+00:00

It is no longer used. Reviewed-by: Jeff Layton Reviewed-by: NeilBrown Signed-off-by: Chuck Lever

SUNRPC: Remove svc_rqst :: rq_vec

2025-05-15T20:16:25+00:00

Clean up: This array is no longer used. On a system with 8-byte pointers and 4KB pages, pahole reports that the rq_vec[] array accounts for 4144 bytes. Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever