From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6BB5AECDFB3 for ; Tue, 17 Jul 2018 06:26:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 24A83208E5 for ; Tue, 17 Jul 2018 06:26:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 24A83208E5 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729652AbeGQG5A (ORCPT ); Tue, 17 Jul 2018 02:57:00 -0400 Received: from szxga04-in.huawei.com ([45.249.212.190]:9630 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728015AbeGQG5A (ORCPT ); Tue, 17 Jul 2018 02:57:00 -0400 Received: from DGGEMS412-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 94AF4172FE010; Tue, 17 Jul 2018 14:25:43 +0800 (CST) Received: from [10.177.253.249] (10.177.253.249) by smtp.huawei.com (10.3.19.212) with Microsoft SMTP Server id 14.3.382.0; Tue, 17 Jul 2018 14:25:40 +0800 To: Dominique Martinet CC: Eric Van Hensbergen , Ron Minnich , Latchesar Ionkov , Linux Kernel Mailing List , From: piaojun Subject: [PATCH v2] net/9p/client.c: fix misuse of spin_lock_irqsave for p9_client lock Message-ID: <5B4D8BD8.3040009@huawei.com> Date: Tue, 17 Jul 2018 14:25:28 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.253.249] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In p9_read_work(), we use spin_lock for client->lock, but misuse spin_lock_irqsave for it in p9_fid_create(). As p9_client lock won't be locked in irq context, so spin_lock is enough. And that will improve the performance. Rebased on 9p-next. Signed-off-by: Jun Piao --- net/9p/client.c | 18 ++++++++---------- net/9p/trans_fd.c | 7 +++---- 2 files changed, 11 insertions(+), 14 deletions(-) diff --git a/net/9p/client.c b/net/9p/client.c index 30f9aee..f6897ee 100644 --- a/net/9p/client.c +++ b/net/9p/client.c @@ -275,14 +275,14 @@ static struct p9_fcall *p9_fcall_alloc(int alloc_msize) INIT_LIST_HEAD(&req->req_list); idr_preload(GFP_NOFS); - spin_lock_irq(&c->lock); + spin_lock(&c->lock); if (type == P9_TVERSION) tag = idr_alloc(&c->reqs, req, P9_NOTAG, P9_NOTAG + 1, GFP_NOWAIT); else tag = idr_alloc(&c->reqs, req, 0, P9_NOTAG, GFP_NOWAIT); req->tc->tag = tag; - spin_unlock_irq(&c->lock); + spin_unlock(&c->lock); idr_preload_end(); if (tag < 0) goto free; @@ -328,13 +328,12 @@ struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag) */ static void p9_free_req(struct p9_client *c, struct p9_req_t *r) { - unsigned long flags; u16 tag = r->tc->tag; p9_debug(P9_DEBUG_MUX, "clnt %p req %p tag: %d\n", c, r, tag); - spin_lock_irqsave(&c->lock, flags); + spin_lock(&c->lock); idr_remove(&c->reqs, tag); - spin_unlock_irqrestore(&c->lock, flags); + spin_unlock(&c->lock); kfree(r->tc); kfree(r->rc); kmem_cache_free(p9_req_cache, r); @@ -846,10 +845,10 @@ static struct p9_fid *p9_fid_create(struct p9_client *clnt) fid->fid = 0; idr_preload(GFP_KERNEL); - spin_lock_irq(&clnt->lock); + spin_lock(&clnt->lock); ret = idr_alloc_u32(&clnt->fids, fid, &fid->fid, P9_NOFID - 1, GFP_NOWAIT); - spin_unlock_irq(&clnt->lock); + spin_unlock(&clnt->lock); idr_preload_end(); if (!ret) @@ -862,13 +861,12 @@ static struct p9_fid *p9_fid_create(struct p9_client *clnt) static void p9_fid_destroy(struct p9_fid *fid) { struct p9_client *clnt; - unsigned long flags; p9_debug(P9_DEBUG_FID, "fid %d\n", fid->fid); clnt = fid->clnt; - spin_lock_irqsave(&clnt->lock, flags); + spin_lock(&clnt->lock); idr_remove(&clnt->fids, fid->fid); - spin_unlock_irqrestore(&clnt->lock, flags); + spin_unlock(&clnt->lock); kfree(fid->rdir); kfree(fid); } diff --git a/net/9p/trans_fd.c b/net/9p/trans_fd.c index bf459ee..94ef685 100644 --- a/net/9p/trans_fd.c +++ b/net/9p/trans_fd.c @@ -197,15 +197,14 @@ static void p9_mux_poll_stop(struct p9_conn *m) static void p9_conn_cancel(struct p9_conn *m, int err) { struct p9_req_t *req, *rtmp; - unsigned long flags; LIST_HEAD(cancel_list); p9_debug(P9_DEBUG_ERROR, "mux %p err %d\n", m, err); - spin_lock_irqsave(&m->client->lock, flags); + spin_lock(&m->client->lock); if (m->err) { - spin_unlock_irqrestore(&m->client->lock, flags); + spin_unlock(&m->client->lock); return; } @@ -217,7 +216,7 @@ static void p9_conn_cancel(struct p9_conn *m, int err) list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, req_list) { list_move(&req->req_list, &cancel_list); } - spin_unlock_irqrestore(&m->client->lock, flags); + spin_unlock(&m->client->lock); list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) { p9_debug(P9_DEBUG_ERROR, "call back req %p\n", req); --