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Mon, 17 Aug 2020 17:58:48 -0800 Received: from MTKMBS02N1.mediatek.inc (172.21.101.77) by MTKMBS62DR.mediatek.inc (172.29.94.18) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Mon, 17 Aug 2020 18:58:46 -0700 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 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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200817_220205_437090_4C9900E1 X-CRM114-Status: GOOD ( 13.28 ) X-Spam-Score: -0.2 (/) X-Spam-Report: SpamAssassin version 3.4.4 on merlin.infradead.org summary: Content analysis details: (-0.2 points) pts rule name description ---- ---------------------- -------------------------------------------------- 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record -0.0 SPF_PASS SPF: sender matches SPF record 0.0 MIME_BASE64_TEXT RAW: Message text disguised using base64 encoding -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain -0.1 DKIM_VALID_EF Message has a valid DKIM or DK signature from envelope-from domain 0.0 UNPARSEABLE_RELAY Informational: message has unparseable relay lines X-BeenThere: linux-mediatek@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-fsdevel@vger.kernel.org, linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, wsd_upstream@mediatek.com Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+patchwork-linux-mediatek=patchwork.kernel.org@lists.infradead.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 */