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 35DFD1DE88F; Tue, 8 Oct 2024 13:07:29 +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=1728392850; cv=none; b=UYkZWMyJa+bztovKLdKtlNr8cy0sc4Cb7zXbtP57QRnDu7VOcvme1CHULzOV5KbMHCDXsHhgcnW/MhcJCzUzdOBe3P/HDjyZady74QFUQUDZsDmMTtR/7Dxru0knb3mJXgICNQVTTtxJVRa/iRjogKRFYQ3HCMCnWl3sDo9LBVM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728392850; c=relaxed/simple; bh=zNgC0l4B0gNOEmLQ6ySG9GD56m7nfCurqRttVlnNiBw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=TxMaJKF5lyhskfvGwTAKY4xtAQKrd9y4+VnWw+TiA6TG0IyJZcnxlq3ozzOAfzhzgiIyZ3w5db7/D+EYY/oszOBQKYILp5xBGZ/n1FGQnDM4EE+Jv6riDGEkckwefgsEoDQmPZrZperemGxhzi0s2lNcJTitQtVPlnKj2D9D204= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=RnZ5bQPb; 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="RnZ5bQPb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6EC1FC4CEC7; Tue, 8 Oct 2024 13:07:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1728392849; bh=zNgC0l4B0gNOEmLQ6ySG9GD56m7nfCurqRttVlnNiBw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RnZ5bQPbRuAyIJYWxHkCytr7TJ+GVUbY6CJqVkdM5DMwM9QRdZ8eoEoL8IWOZKuIt a8qZCKeTjyaVsWNP+zA5L3Y1ad8pfPgThfrEmxHa1UDZALgPGNYraCzFtyi6ILf1D7 e/64piOlp+rQrF7REUpqOaSxHq5pd6Jl833JQvzQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, NeilBrown , Chuck Lever , Sasha Levin Subject: [PATCH 6.11 537/558] sunrpc: change sp_nrthreads from atomic_t to unsigned int. Date: Tue, 8 Oct 2024 14:09:27 +0200 Message-ID: <20241008115723.365178179@linuxfoundation.org> X-Mailer: git-send-email 2.46.2 In-Reply-To: <20241008115702.214071228@linuxfoundation.org> References: <20241008115702.214071228@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 6.11-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 34eb2c2cbcde3..e8704a4e848ca 100644 --- a/fs/nfsd/nfsctl.c +++ b/fs/nfsd/nfsctl.c @@ -1762,7 +1762,7 @@ 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 0bc8eaa5e0098..8103c3c90cd11 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 a7d0406b9ef59..6811681033c0f 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 88a59cfa5583c..df06b152ed94e 100644 --- a/net/sunrpc/svc.c +++ b/net/sunrpc/svc.c @@ -713,7 +713,7 @@ 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() @@ -768,31 +768,22 @@ 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 @@ -871,7 +862,7 @@ 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); @@ -959,7 +950,7 @@ 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