From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 14EFB192594; Tue, 8 Oct 2024 12:36:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728390999; cv=none; b=ZN25HK105tq6+9BKVYoLY6oY6BbaS2IoCKlgLT8geAA4fEhbxx2yShsp9VJdEWn5/S3qVX9EtHpxETF+TDFwfHKVBuJa+tz4wdiOiMBve8JwKVGpu2jMon7vNK852xR7QETqtwWlZHWjsQsyRTLU0BBb5AM3ZoI0HJm6lrt3cgw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728390999; c=relaxed/simple; bh=WMofMWMtjfCeJGcrayBGUx2SWJWxnc/WOo5gmakumMI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=q2/4wYVc6Lad6BfUb/Umq9yuBxNq12wmOnTA+oY1ENViGJZAD+wuyYsgyGukpfTM52I9cmkkSEUZZfwPxp3APmtmxaxBIf3o3VmfHR2dVbt1/KvVybkUYwFaSFtEhLaX1Etnc3O/hRPRTOQq5OTyoT7EeOJbtJz9w2i3NvKv8x0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=OEVsXTBW; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="OEVsXTBW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 303D0C4CECD; Tue, 8 Oct 2024 12:36:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1728390998; bh=WMofMWMtjfCeJGcrayBGUx2SWJWxnc/WOo5gmakumMI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OEVsXTBWQ0KoBSrkjXHQEZwnYSG1dOYB0Uv3AwlodozfscF5F1zXTrW1EOPL2XJwc znezC3KKLvk8UwpLLL1X9urElGtI6xBQTx5wIKHuY6C7OmQtMD4gUTab9j5BUCxWX/ 8I8ITR6vtIPz/C3rwx2HqrJntL8Gp07ofY3mYfLM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, NeilBrown , Chuck Lever , Sasha Levin Subject: [PATCH 6.10 458/482] sunrpc: change sp_nrthreads from atomic_t to unsigned int. Date: Tue, 8 Oct 2024 14:08:41 +0200 Message-ID: <20241008115706.539649865@linuxfoundation.org> X-Mailer: git-send-email 2.46.2 In-Reply-To: <20241008115648.280954295@linuxfoundation.org> References: <20241008115648.280954295@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: NeilBrown [ Upstream commit 60749cbe3d8ae572a6c7dda675de3e8b25797a18 ] sp_nrthreads is only ever accessed under the service mutex nlmsvc_mutex nfs_callback_mutex nfsd_mutex so these is no need for it to be an atomic_t. The fact that all code using it is single-threaded means that we can simplify svc_pool_victim and remove the temporary elevation of sp_nrthreads. Signed-off-by: NeilBrown Signed-off-by: Chuck Lever Stable-dep-of: aadc3bbea163 ("NFSD: Limit the number of concurrent async COPY operations") Signed-off-by: Sasha Levin --- fs/nfsd/nfsctl.c | 2 +- fs/nfsd/nfssvc.c | 2 +- include/linux/sunrpc/svc.h | 4 ++-- net/sunrpc/svc.c | 31 +++++++++++-------------------- 4 files changed, 15 insertions(+), 24 deletions(-) diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c index 0f9b4f7b56cd8..37f619ccafce0 100644 --- a/fs/nfsd/nfsctl.c +++ b/fs/nfsd/nfsctl.c @@ -1746,7 +1746,7 @@ int nfsd_nl_threads_get_doit(struct sk_buff *skb, struct genl_info *info) struct svc_pool *sp = &nn->nfsd_serv->sv_pools[i]; err = nla_put_u32(skb, NFSD_A_SERVER_THREADS, - atomic_read(&sp->sp_nrthreads)); + sp->sp_nrthreads); if (err) goto err_unlock; } diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c index 89d7918de7b1a..877f926356549 100644 --- a/fs/nfsd/nfssvc.c +++ b/fs/nfsd/nfssvc.c @@ -705,7 +705,7 @@ int nfsd_get_nrthreads(int n, int *nthreads, struct net *net) if (serv) for (i = 0; i < serv->sv_nrpools && i < n; i++) - nthreads[i] = atomic_read(&serv->sv_pools[i].sp_nrthreads); + nthreads[i] = serv->sv_pools[i].sp_nrthreads; return 0; } diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h index 23617da0e565e..38a4fdf784e9a 100644 --- a/include/linux/sunrpc/svc.h +++ b/include/linux/sunrpc/svc.h @@ -33,9 +33,9 @@ * node traffic on multi-node NUMA NFS servers. */ struct svc_pool { - unsigned int sp_id; /* pool id; also node id on NUMA */ + unsigned int sp_id; /* pool id; also node id on NUMA */ struct lwq sp_xprts; /* pending transports */ - atomic_t sp_nrthreads; /* # of threads in pool */ + unsigned int sp_nrthreads; /* # of threads in pool */ struct list_head sp_all_threads; /* all server threads */ struct llist_head sp_idle_threads; /* idle server threads */ diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c index d9cda1e53a017..6a15b831589c0 100644 --- a/net/sunrpc/svc.c +++ b/net/sunrpc/svc.c @@ -682,7 +682,7 @@ svc_prepare_thread(struct svc_serv *serv, struct svc_pool *pool, int node) serv->sv_nrthreads += 1; spin_unlock_bh(&serv->sv_lock); - atomic_inc(&pool->sp_nrthreads); + pool->sp_nrthreads += 1; /* Protected by whatever lock the service uses when calling * svc_set_num_threads() @@ -737,31 +737,22 @@ svc_pool_victim(struct svc_serv *serv, struct svc_pool *target_pool, struct svc_pool *pool; unsigned int i; -retry: pool = target_pool; - if (pool != NULL) { - if (atomic_inc_not_zero(&pool->sp_nrthreads)) - goto found_pool; - return NULL; - } else { + if (!pool) { for (i = 0; i < serv->sv_nrpools; i++) { pool = &serv->sv_pools[--(*state) % serv->sv_nrpools]; - if (atomic_inc_not_zero(&pool->sp_nrthreads)) - goto found_pool; + if (pool->sp_nrthreads) + break; } - return NULL; } -found_pool: - set_bit(SP_VICTIM_REMAINS, &pool->sp_flags); - set_bit(SP_NEED_VICTIM, &pool->sp_flags); - if (!atomic_dec_and_test(&pool->sp_nrthreads)) + if (pool && pool->sp_nrthreads) { + set_bit(SP_VICTIM_REMAINS, &pool->sp_flags); + set_bit(SP_NEED_VICTIM, &pool->sp_flags); return pool; - /* Nothing left in this pool any more */ - clear_bit(SP_NEED_VICTIM, &pool->sp_flags); - clear_bit(SP_VICTIM_REMAINS, &pool->sp_flags); - goto retry; + } + return NULL; } static int @@ -840,7 +831,7 @@ svc_set_num_threads(struct svc_serv *serv, struct svc_pool *pool, int nrservs) if (!pool) nrservs -= serv->sv_nrthreads; else - nrservs -= atomic_read(&pool->sp_nrthreads); + nrservs -= pool->sp_nrthreads; if (nrservs > 0) return svc_start_kthreads(serv, pool, nrservs); @@ -928,7 +919,7 @@ svc_exit_thread(struct svc_rqst *rqstp) list_del_rcu(&rqstp->rq_all); - atomic_dec(&pool->sp_nrthreads); + pool->sp_nrthreads -= 1; spin_lock_bh(&serv->sv_lock); serv->sv_nrthreads -= 1; -- 2.43.0