From patchwork Thu Mar 14 00:11:51 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: NeilBrown X-Patchwork-Id: 10851999 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0F8DA1515 for ; Thu, 14 Mar 2019 00:15:22 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EE59329D1C for ; Thu, 14 Mar 2019 00:15:21 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E26A529D2D; Thu, 14 Mar 2019 00:15:21 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from pdx1-mailman02.dreamhost.com (pdx1-mailman02.dreamhost.com [64.90.62.194]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 9956F29D1C for ; Thu, 14 Mar 2019 00:15:21 +0000 (UTC) Received: from pdx1-mailman02.dreamhost.com (localhost [IPv6:::1]) by pdx1-mailman02.dreamhost.com (Postfix) with ESMTP id 1CAA9720131; Wed, 13 Mar 2019 17:15:21 -0700 (PDT) X-Original-To: lustre-devel@lists.lustre.org Delivered-To: lustre-devel-lustre.org@pdx1-mailman02.dreamhost.com Received: from mx1.suse.de (mx2.suse.de [195.135.220.15]) by pdx1-mailman02.dreamhost.com (Postfix) with ESMTP id 960A9720011 for ; Wed, 13 Mar 2019 17:15:19 -0700 (PDT) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id D578DAF5F; Thu, 14 Mar 2019 00:15:18 +0000 (UTC) From: NeilBrown To: Andreas Dilger , James Simmons , Oleg Drokin Date: Thu, 14 Mar 2019 11:11:51 +1100 Message-ID: <155252231106.26912.1651233909473573691.stgit@noble.brown> In-Reply-To: <155252182126.26912.1842463462595601611.stgit@noble.brown> References: <155252182126.26912.1842463462595601611.stgit@noble.brown> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Subject: [lustre-devel] [PATCH 23/32] lustre: ptlrpc: make ptlrpc_last_xid an atomic64_t X-BeenThere: lustre-devel@lists.lustre.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "For discussing Lustre software development." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Lustre Development List Errors-To: lustre-devel-bounces@lists.lustre.org Sender: "lustre-devel" X-Virus-Scanned: ClamAV using ClamSMTP This variable is treated like ant atomic64_t, so change it's type and simplify the code. Signed-off-by: NeilBrown Reviewed-by: Andreas Dilger --- drivers/staging/lustre/lustre/ptlrpc/client.c | 39 ++++++------------------- 1 file changed, 10 insertions(+), 29 deletions(-) diff --git a/drivers/staging/lustre/lustre/ptlrpc/client.c b/drivers/staging/lustre/lustre/ptlrpc/client.c index 2514a142e799..ddf44c854200 100644 --- a/drivers/staging/lustre/lustre/ptlrpc/client.c +++ b/drivers/staging/lustre/lustre/ptlrpc/client.c @@ -2999,8 +2999,7 @@ void ptlrpc_abort_set(struct ptlrpc_request_set *set) } } -static u64 ptlrpc_last_xid; -static spinlock_t ptlrpc_last_xid_lock; +static atomic64_t ptlrpc_last_xid; /** * Initialize the XID for the node. This is common among all requests on @@ -3021,19 +3020,20 @@ static spinlock_t ptlrpc_last_xid_lock; void ptlrpc_init_xid(void) { time64_t now = ktime_get_real_seconds(); + u64 xid; - spin_lock_init(&ptlrpc_last_xid_lock); if (now < YEAR_2004) { - get_random_bytes(&ptlrpc_last_xid, sizeof(ptlrpc_last_xid)); - ptlrpc_last_xid >>= 2; - ptlrpc_last_xid |= (1ULL << 61); + get_random_bytes(&xid, sizeof(xid)); + xid >>= 2; + xid |= (1ULL << 61); } else { - ptlrpc_last_xid = (u64)now << 20; + xid = (u64)now << 20; } /* Always need to be aligned to a power-of-two for multi-bulk BRW */ BUILD_BUG_ON(((PTLRPC_BULK_OPS_COUNT - 1) & PTLRPC_BULK_OPS_COUNT) != 0); - ptlrpc_last_xid &= PTLRPC_BULK_OPS_MASK; + xid &= PTLRPC_BULK_OPS_MASK; + atomic64_set(&ptlrpc_last_xid, xid); } /** @@ -3050,14 +3050,7 @@ void ptlrpc_init_xid(void) */ u64 ptlrpc_next_xid(void) { - u64 next; - - spin_lock(&ptlrpc_last_xid_lock); - next = ptlrpc_last_xid + PTLRPC_BULK_OPS_COUNT; - ptlrpc_last_xid = next; - spin_unlock(&ptlrpc_last_xid_lock); - - return next; + return atomic64_add_return(PTLRPC_BULK_OPS_COUNT, &ptlrpc_last_xid); } /** @@ -3131,19 +3124,7 @@ void ptlrpc_set_bulk_mbits(struct ptlrpc_request *req) */ u64 ptlrpc_sample_next_xid(void) { -#if BITS_PER_LONG == 32 - /* need to avoid possible word tearing on 32-bit systems */ - u64 next; - - spin_lock(&ptlrpc_last_xid_lock); - next = ptlrpc_last_xid + PTLRPC_BULK_OPS_COUNT; - spin_unlock(&ptlrpc_last_xid_lock); - - return next; -#else - /* No need to lock, since returned value is racy anyways */ - return ptlrpc_last_xid + PTLRPC_BULK_OPS_COUNT; -#endif + return atomic64_read(&ptlrpc_last_xid) + PTLRPC_BULK_OPS_COUNT; } EXPORT_SYMBOL(ptlrpc_sample_next_xid);