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authorPeter Hurley <peter@hurleysoftware.com>2013-06-15 17:36:12 +0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-07-24 03:47:09 +0400
commit8c1fb49ba107c7db9441ef6ec0ab5830d112cc2a (patch)
treec4733126d13fdf57e10638c18da280c0e7e103ac /include/linux/tty.h
parentd7a68be4f265be10e24be931c257af30ca55566b (diff)
downloadlinux-8c1fb49ba107c7db9441ef6ec0ab5830d112cc2a.tar.xz
tty: Avoid false-sharing flip buffer ptrs
Separate the head and tail ptrs to avoid cache-line contention (so called 'false-sharing') between concurrent threads. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/linux/tty.h')
-rw-r--r--include/linux/tty.h4
1 files changed, 2 insertions, 2 deletions
diff --git a/include/linux/tty.h b/include/linux/tty.h
index 1d5bacca3652..b8e8adf95bf3 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -65,13 +65,13 @@ static inline char *flag_buf_ptr(struct tty_buffer *b, int ofs)
struct tty_bufhead {
+ struct tty_buffer *head; /* Queue head */
struct work_struct work;
struct mutex flush_mutex;
struct tty_buffer sentinel;
- struct tty_buffer *head; /* Queue head */
- struct tty_buffer *tail; /* Active buffer */
struct llist_head free; /* Free queue head */
atomic_t memory_used; /* In-use buffers excluding free list */
+ struct tty_buffer *tail; /* Active buffer */
};
/*
* When a break, frame error, or parity error happens, these codes are