From: ling.ma.program@gmail.com
To: linux-kernel@vger.kernel.org
Cc: ling.ml@antfin.com
Subject: [RFC PATCH] locks:Remove spinlock in unshare_files
Date: Fri, 13 Mar 2020 11:10:17 +0800 [thread overview]
Message-ID: <20200313031017.71090-1-ling.ma.program@gmail.com> (raw)
From: Ma Ling <ling.ml@antfin.com>
Processor support atomic operation for long/int/short/char type,
we use the feature to avoid spinlock, which cost hundreds cycles.
Appreciate your comments
Ling
Signed-off-by: Ma Ling <ling.ml@antfin.com>
---
kernel/fork.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/kernel/fork.c b/kernel/fork.c
index 60a1295..fe54600 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -3041,9 +3041,7 @@ int unshare_files(struct files_struct **displaced)
return error;
}
*displaced = task->files;
- task_lock(task);
- task->files = copy;
- task_unlock(task);
+ WRITE_ONCE(task->files, copy);
return 0;
}
--
1.8.3.1
next reply other threads:[~2020-03-13 3:10 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-13 3:10 ling.ma.program [this message]
2020-03-16 13:25 ` [RFC PATCH] locks:Remove spinlock in unshare_files Ling Ma
2020-03-16 13:39 ` Peter Zijlstra
2020-03-16 18:35 ` Al Viro
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