From: Chinwen Chang <chinwen.chang@mediatek.com>
To: Matthias Brugger <matthias.bgg@gmail.com>,
Michel Lespinasse <walken@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
Vlastimil Babka <vbabka@suse.cz>,
Daniel Jordan <daniel.m.jordan@oracle.com>,
Davidlohr Bueso <dbueso@suse.de>,
Chinwen Chang <chinwen.chang@mediatek.com>,
Alexey Dobriyan <adobriyan@gmail.com>,
"Matthew Wilcox (Oracle)" <willy@infradead.org>,
Jason Gunthorpe <jgg@ziepe.ca>,
Steven Price <steven.price@arm.com>,
Song Liu <songliubraving@fb.com>,
Jimmy Assarsson <jimmyassarsson@gmail.com>,
Huang Ying <ying.huang@intel.com>
Cc: <linux-kernel@vger.kernel.org>,
<linux-arm-kernel@lists.infradead.org>,
<linux-mediatek@lists.infradead.org>,
<linux-fsdevel@vger.kernel.org>, <wsd_upstream@mediatek.com>
Subject: [PATCH v2 1/2] mmap locking API: add mmap_lock_is_contended()
Date: Thu, 13 Aug 2020 10:13:29 +0800 [thread overview]
Message-ID: <1597284810-17454-2-git-send-email-chinwen.chang@mediatek.com> (raw)
In-Reply-To: <1597284810-17454-1-git-send-email-chinwen.chang@mediatek.com>
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 <chinwen.chang@mediatek.com>
---
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 */
--
1.9.1
next prev parent reply other threads:[~2020-08-13 2:13 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-13 2:13 [PATCH v2 0/2] Try to release mmap_lock temporarily in smaps_rollup Chinwen Chang
2020-08-13 2:13 ` Chinwen Chang [this message]
2020-08-13 8:21 ` [PATCH v2 1/2] mmap locking API: add mmap_lock_is_contended() Steven Price
2020-08-14 8:30 ` Michel Lespinasse
2020-08-13 2:13 ` [PATCH v2 2/2] mm: proc: smaps_rollup: do not stall write attempts on mmap_lock Chinwen Chang
2020-08-13 8:21 ` Steven Price
2020-08-14 8:35 ` Michel Lespinasse
2020-08-14 9:08 ` Chinwen Chang
2020-08-13 9:53 ` [PATCH v2 0/2] Try to release mmap_lock temporarily in smaps_rollup Michel Lespinasse
2020-08-13 16:11 ` Chinwen Chang
2020-08-14 8:29 ` Michel Lespinasse
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