From 9867d76ca16b3f455f9ca83861f4ce5c94a25928 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Tue, 10 Jun 2008 08:40:38 -0400 Subject: [PATCH] knfsd: convert knfsd to kthread API This patch is rather large, but I couldn't figure out a way to break it up that would remain bisectable. It does several things: - change svc_thread_fn typedef to better match what kthread_create expects - change svc_pool_map_set_cpumask to be more kthread friendly. Make it take a task arg and and get rid of the "oldmask" - have svc_set_num_threads call kthread_create directly - eliminate __svc_create_thread Signed-off-by: Jeff Layton Signed-off-by: J. Bruce Fields --- fs/nfsd/nfssvc.c | 45 +++++++++++------ include/linux/sunrpc/svc.h | 2 +- net/sunrpc/svc.c | 100 +++++++++++++------------------------ 3 files changed, 64 insertions(+), 83 deletions(-) diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c index 6339cb70a0..9e21568137 100644 --- a/fs/nfsd/nfssvc.c +++ b/fs/nfsd/nfssvc.c @@ -21,6 +21,7 @@ #include #include #include +#include #include #include @@ -46,7 +47,7 @@ #define SHUTDOWN_SIGS (sigmask(SIGKILL) | sigmask(SIGHUP) | sigmask(SIGINT) | sigmask(SIGQUIT)) extern struct svc_program nfsd_program; -static void nfsd(struct svc_rqst *rqstp); +static int nfsd(void *vrqstp); struct timeval nfssvc_boot; static atomic_t nfsd_busy; static unsigned long nfsd_last_call; @@ -407,18 +408,19 @@ update_thread_usage(int busy_threads) /* * This is the NFS server kernel thread */ -static void -nfsd(struct svc_rqst *rqstp) +static int +nfsd(void *vrqstp) { + struct svc_rqst *rqstp = (struct svc_rqst *) vrqstp; struct fs_struct *fsp; - int err; sigset_t shutdown_mask, allowed_mask; + int err, preverr = 0; + unsigned int signo; /* Lock module and set up kernel thread */ mutex_lock(&nfsd_mutex); - daemonize("nfsd"); - /* After daemonize() this kernel thread shares current->fs + /* At this point, the thread shares current->fs * with the init process. We need to create files with a * umask of 0 instead of init's umask. */ fsp = copy_fs_struct(current->fs); @@ -433,14 +435,18 @@ nfsd(struct svc_rqst *rqstp) siginitsetinv(&shutdown_mask, SHUTDOWN_SIGS); siginitsetinv(&allowed_mask, ALLOWED_SIGS); + /* + * thread is spawned with all signals set to SIG_IGN, re-enable + * the ones that matter + */ + for (signo = 1; signo <= _NSIG; signo++) { + if (!sigismember(&shutdown_mask, signo)) + allow_signal(signo); + } nfsdstats.th_cnt++; - - rqstp->rq_task = current; - mutex_unlock(&nfsd_mutex); - /* * We want less throttling in balance_dirty_pages() so that nfs to * localhost doesn't cause nfsd to lock up due to all the client's @@ -462,15 +468,25 @@ nfsd(struct svc_rqst *rqstp) */ while ((err = svc_recv(rqstp, 60*60*HZ)) == -EAGAIN) ; - if (err < 0) + if (err == -EINTR) break; + else if (err < 0) { + if (err != preverr) { + printk(KERN_WARNING "%s: unexpected error " + "from svc_recv (%d)\n", __func__, -err); + preverr = err; + } + schedule_timeout_uninterruptible(HZ); + continue; + } + update_thread_usage(atomic_read(&nfsd_busy)); atomic_inc(&nfsd_busy); /* Lock the export hash tables for reading. */ exp_readlock(); - /* Process request with signals blocked. */ + /* Process request with signals blocked. */ sigprocmask(SIG_SETMASK, &allowed_mask, NULL); svc_process(rqstp); @@ -481,14 +497,10 @@ nfsd(struct svc_rqst *rqstp) atomic_dec(&nfsd_busy); } - if (err != -EINTR) - printk(KERN_WARNING "nfsd: terminating on error %d\n", -err); - /* Clear signals before calling svc_exit_thread() */ flush_signals(current); mutex_lock(&nfsd_mutex); - nfsdstats.th_cnt --; out: @@ -498,6 +510,7 @@ out: /* Release module */ mutex_unlock(&nfsd_mutex); module_put_and_exit(0); + return 0; } static __be32 map_new_errors(u32 vers, __be32 nfserr) diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h index 4b54c5fdcf..011d6d8100 100644 --- a/include/linux/sunrpc/svc.h +++ b/include/linux/sunrpc/svc.h @@ -22,7 +22,7 @@ /* * This is the RPC server thread function prototype */ -typedef void (*svc_thread_fn)(struct svc_rqst *); +typedef int (*svc_thread_fn)(void *); /* * diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c index 7bffaff2a3..03a9f1a9e7 100644 --- a/net/sunrpc/svc.c +++ b/net/sunrpc/svc.c @@ -18,6 +18,7 @@ #include #include #include +#include #include #include @@ -291,15 +292,14 @@ svc_pool_map_put(void) /* - * Set the current thread's cpus_allowed mask so that it + * Set the given thread's cpus_allowed mask so that it * will only run on cpus in the given pool. - * - * Returns 1 and fills in oldmask iff a cpumask was applied. */ -static inline int -svc_pool_map_set_cpumask(unsigned int pidx, cpumask_t *oldmask) +static inline void +svc_pool_map_set_cpumask(struct task_struct *task, unsigned int pidx) { struct svc_pool_map *m = &svc_pool_map; + unsigned int node = m->pool_to[pidx]; /* * The caller checks for sv_nrpools > 1, which @@ -307,26 +307,17 @@ svc_pool_map_set_cpumask(unsigned int pidx, cpumask_t *oldmask) */ BUG_ON(m->count == 0); - switch (m->mode) - { - default: - return 0; + switch (m->mode) { case SVC_POOL_PERCPU: { - unsigned int cpu = m->pool_to[pidx]; - - *oldmask = current->cpus_allowed; - set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu)); - return 1; + set_cpus_allowed_ptr(task, &cpumask_of_cpu(node)); + break; } case SVC_POOL_PERNODE: { - unsigned int node = m->pool_to[pidx]; node_to_cpumask_ptr(nodecpumask, node); - - *oldmask = current->cpus_allowed; - set_cpus_allowed_ptr(current, nodecpumask); - return 1; + set_cpus_allowed_ptr(task, nodecpumask); + break; } } } @@ -578,47 +569,6 @@ out_enomem: } EXPORT_SYMBOL(svc_prepare_thread); -/* - * Create a thread in the given pool. Caller must hold BKL or another lock to - * serialize access to the svc_serv struct. On a NUMA or SMP machine, with a - * multi-pool serv, the thread will be restricted to run on the cpus belonging - * to the pool. - */ -static int -__svc_create_thread(svc_thread_fn func, struct svc_serv *serv, - struct svc_pool *pool) -{ - struct svc_rqst *rqstp; - int error = -ENOMEM; - int have_oldmask = 0; - cpumask_t uninitialized_var(oldmask); - - rqstp = svc_prepare_thread(serv, pool); - if (IS_ERR(rqstp)) { - error = PTR_ERR(rqstp); - goto out; - } - - if (serv->sv_nrpools > 1) - have_oldmask = svc_pool_map_set_cpumask(pool->sp_id, &oldmask); - - error = kernel_thread((int (*)(void *)) func, rqstp, 0); - - if (have_oldmask) - set_cpus_allowed(current, oldmask); - - if (error < 0) - goto out_thread; - svc_sock_update_bufs(serv); - error = 0; -out: - return error; - -out_thread: - svc_exit_thread(rqstp); - goto out; -} - /* * Choose a pool in which to create a new thread, for svc_set_num_threads */ @@ -688,7 +638,9 @@ found_pool: int svc_set_num_threads(struct svc_serv *serv, struct svc_pool *pool, int nrservs) { - struct task_struct *victim; + struct svc_rqst *rqstp; + struct task_struct *task; + struct svc_pool *chosen_pool; int error = 0; unsigned int state = serv->sv_nrthreads-1; @@ -704,18 +656,34 @@ svc_set_num_threads(struct svc_serv *serv, struct svc_pool *pool, int nrservs) /* create new threads */ while (nrservs > 0) { nrservs--; + chosen_pool = choose_pool(serv, pool, &state); + + rqstp = svc_prepare_thread(serv, chosen_pool); + if (IS_ERR(rqstp)) { + error = PTR_ERR(rqstp); + break; + } + __module_get(serv->sv_module); - error = __svc_create_thread(serv->sv_function, serv, - choose_pool(serv, pool, &state)); - if (error < 0) { + task = kthread_create(serv->sv_function, rqstp, serv->sv_name); + if (IS_ERR(task)) { + error = PTR_ERR(task); module_put(serv->sv_module); + svc_exit_thread(rqstp); break; } + + rqstp->rq_task = task; + if (serv->sv_nrpools > 1) + svc_pool_map_set_cpumask(task, chosen_pool->sp_id); + + svc_sock_update_bufs(serv); + wake_up_process(task); } /* destroy old threads */ while (nrservs < 0 && - (victim = choose_victim(serv, pool, &state)) != NULL) { - send_sig(serv->sv_kill_signal, victim, 1); + (task = choose_victim(serv, pool, &state)) != NULL) { + send_sig(serv->sv_kill_signal, task, 1); nrservs++; } -- 2.39.5