diff options
author | NeilBrown <neilb@suse.de> | 2023-09-11 17:39:04 +0300 |
---|---|---|
committer | Chuck Lever <chuck.lever@oracle.com> | 2023-10-16 19:44:04 +0300 |
commit | fa341560ca7458f4396d5a0771cb5f2358d8535d (patch) | |
tree | c8c18f267b8d7443da0e0dc581637b9c77353a9c /include/linux/sunrpc | |
parent | f4578ba11c4a211d45877babe56c84d922301576 (diff) | |
download | linux-fa341560ca7458f4396d5a0771cb5f2358d8535d.tar.xz |
SUNRPC: change how svc threads are asked to exit.
svc threads are currently stopped using kthread_stop(). This requires
identifying a specific thread. However we don't care which thread
stops, just as long as one does.
So instead, set a flag in the svc_pool to say that a thread needs to
die, and have each thread check this flag instead of calling
kthread_should_stop(). The first thread to find and clear this flag
then moves towards exiting.
This removes an explicit dependency on sp_all_threads which will make a
future patch simpler.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Diffstat (limited to 'include/linux/sunrpc')
-rw-r--r-- | include/linux/sunrpc/svc.h | 26 |
1 files changed, 25 insertions, 1 deletions
diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h index acbe1314febd..0ec691070e27 100644 --- a/include/linux/sunrpc/svc.h +++ b/include/linux/sunrpc/svc.h @@ -50,6 +50,8 @@ struct svc_pool { enum { SP_TASK_PENDING, /* still work to do even if no xprt is queued */ SP_CONGESTED, /* all threads are busy, none idle */ + SP_NEED_VICTIM, /* One thread needs to agree to exit */ + SP_VICTIM_REMAINS, /* One thread needs to actually exit */ }; @@ -259,7 +261,7 @@ enum { RQ_DROPME, /* drop current reply */ RQ_SPLICE_OK, /* turned off in gss privacy to prevent * encrypting page cache pages */ - RQ_VICTIM, /* about to be shut down */ + RQ_VICTIM, /* Have agreed to shut down */ RQ_BUSY, /* request is busy */ RQ_DATA, /* request has data */ }; @@ -299,6 +301,28 @@ static inline struct sockaddr *svc_daddr(const struct svc_rqst *rqst) return (struct sockaddr *) &rqst->rq_daddr; } +/** + * svc_thread_should_stop - check if this thread should stop + * @rqstp: the thread that might need to stop + * + * To stop an svc thread, the pool flags SP_NEED_VICTIM and SP_VICTIM_REMAINS + * are set. The first thread which sees SP_NEED_VICTIM clears it, becoming + * the victim using this function. It should then promptly call + * svc_exit_thread() to complete the process, clearing SP_VICTIM_REMAINS + * so the task waiting for a thread to exit can wake and continue. + * + * Return values: + * %true: caller should invoke svc_exit_thread() + * %false: caller should do nothing + */ +static inline bool svc_thread_should_stop(struct svc_rqst *rqstp) +{ + if (test_and_clear_bit(SP_NEED_VICTIM, &rqstp->rq_pool->sp_flags)) + set_bit(RQ_VICTIM, &rqstp->rq_flags); + + return test_bit(RQ_VICTIM, &rqstp->rq_flags); +} + struct svc_deferred_req { u32 prot; /* protocol (UDP or TCP) */ struct svc_xprt *xprt; |