From patchwork Tue Aug 18 01:58:16 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chinwen Chang X-Patchwork-Id: 11719653 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 96A9C618 for ; Tue, 18 Aug 2020 01:59:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7E7EE2075E for ; Tue, 18 Aug 2020 01:59:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=mediatek.com header.i=@mediatek.com header.b="k1VuBask" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726633AbgHRB7B (ORCPT ); Mon, 17 Aug 2020 21:59:01 -0400 Received: from mailgw01.mediatek.com ([210.61.82.183]:51887 "EHLO mailgw01.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726357AbgHRB6w (ORCPT ); Mon, 17 Aug 2020 21:58:52 -0400 X-UUID: 5077dca911e7440cbd4072a0c1bf4bd1-20200818 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=mediatek.com; s=dk; h=Content-Transfer-Encoding:Content-Type:MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:CC:To:From; bh=Mg5uZdFFDJBYK66PxAT2X+zp5o0L419XdVPA3e+0npM=; b=k1VuBaskvYwEgkpsX/B8HgEUdXyfZocMjm0013OY0Wc95x9LxPiKxIzIMI7T/mCQhwh68pkCL3vU5lEzjck9YSKlZt6G5VQt9vCb3IKg19rH/GkhxrILRhBbaySFtrHTAncHo5UaSWV7aiNgNzOo48OI1mu152ZxWXxntNM0smA=; X-UUID: 5077dca911e7440cbd4072a0c1bf4bd1-20200818 Received: from mtkcas08.mediatek.inc [(172.21.101.126)] by mailgw01.mediatek.com (envelope-from ) (Cellopoint E-mail Firewall v4.1.10 Build 0809 with TLS) with ESMTP id 731042030; Tue, 18 Aug 2020 09:58:48 +0800 Received: from mtkcas08.mediatek.inc (172.21.101.126) by mtkmbs02n1.mediatek.inc (172.21.101.77) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Tue, 18 Aug 2020 09:58:44 +0800 Received: from mtkswgap22.mediatek.inc (172.21.77.33) by mtkcas08.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Tue, 18 Aug 2020 09:58:44 +0800 From: Chinwen Chang To: Matthias Brugger , Michel Lespinasse , Andrew Morton , Vlastimil Babka , Daniel Jordan , Davidlohr Bueso , Chinwen Chang , Alexey Dobriyan , "Matthew Wilcox (Oracle)" , Jason Gunthorpe , Steven Price , Song Liu , Jimmy Assarsson , Huang Ying , Daniel Kiss , Laurent Dufour CC: , , , , Subject: [PATCH v4 1/3] mmap locking API: add mmap_lock_is_contended() Date: Tue, 18 Aug 2020 09:58:16 +0800 Message-ID: <1597715898-3854-2-git-send-email-chinwen.chang@mediatek.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1597715898-3854-1-git-send-email-chinwen.chang@mediatek.com> References: <1597715898-3854-1-git-send-email-chinwen.chang@mediatek.com> MIME-Version: 1.0 X-MTK: N Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Add new API to query if someone wants to acquire mmap_lock for write attempts. Using this instead of rwsem_is_contended makes it more tolerant of future changes to the lock type. Signed-off-by: Chinwen Chang Reviewed-by: Steven Price Acked-by: Michel Lespinasse --- include/linux/mmap_lock.h | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/include/linux/mmap_lock.h b/include/linux/mmap_lock.h index 0707671..18e7eae 100644 --- a/include/linux/mmap_lock.h +++ b/include/linux/mmap_lock.h @@ -87,4 +87,9 @@ static inline void mmap_assert_write_locked(struct mm_struct *mm) VM_BUG_ON_MM(!rwsem_is_locked(&mm->mmap_lock), mm); } +static inline int mmap_lock_is_contended(struct mm_struct *mm) +{ + return rwsem_is_contended(&mm->mmap_lock); +} + #endif /* _LINUX_MMAP_LOCK_H */