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[Qemu-devel] [PATCH V2 4/6] ftrace: Allow stealing pages from pipe buffe
From: |
Yoshihiro YUNOMAE |
Subject: |
[Qemu-devel] [PATCH V2 4/6] ftrace: Allow stealing pages from pipe buffer |
Date: |
Thu, 09 Aug 2012 21:31:10 +0900 |
User-agent: |
StGIT/0.14.3 |
From: Masami Hiramatsu <address@hidden>
Use generic steal operation on pipe buffer to allow stealing
ring buffer's read page from pipe buffer.
Note that this could reduce the performance of splice on the
splice_write side operation without affinity setting.
Since the ring buffer's read pages are allocated on the
tracing-node, but the splice user does not always execute
splice write side operation on the same node. In this case,
the page will be accessed from the another node.
Thus, it is strongly recommended to assign the splicing
thread to corresponding node.
Signed-off-by: Masami Hiramatsu <address@hidden>
Acked-by: Steven Rostedt <address@hidden>
---
kernel/trace/trace.c | 8 +-------
1 files changed, 1 insertions(+), 7 deletions(-)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index a120f98..ae01930 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -4194,12 +4194,6 @@ static void buffer_pipe_buf_release(struct
pipe_inode_info *pipe,
buf->private = 0;
}
-static int buffer_pipe_buf_steal(struct pipe_inode_info *pipe,
- struct pipe_buffer *buf)
-{
- return 1;
-}
-
static void buffer_pipe_buf_get(struct pipe_inode_info *pipe,
struct pipe_buffer *buf)
{
@@ -4215,7 +4209,7 @@ static const struct pipe_buf_operations
buffer_pipe_buf_ops = {
.unmap = generic_pipe_buf_unmap,
.confirm = generic_pipe_buf_confirm,
.release = buffer_pipe_buf_release,
- .steal = buffer_pipe_buf_steal,
+ .steal = generic_pipe_buf_steal,
.get = buffer_pipe_buf_get,
};
- [Qemu-devel] [PATCH V2 0/6] virtio-trace: Support virtio-trace, Yoshihiro YUNOMAE, 2012/08/09
- [Qemu-devel] [PATCH V2 1/6] virtio/console: Add splice_write support, Yoshihiro YUNOMAE, 2012/08/09
- [Qemu-devel] [PATCH V2 2/6] virtio/console: Add a failback for unstealable pipe buffer, Yoshihiro YUNOMAE, 2012/08/09
- [Qemu-devel] [PATCH V2 3/6] virtio/console: Wait until the port is ready on splice, Yoshihiro YUNOMAE, 2012/08/09
- [Qemu-devel] [PATCH V2 4/6] ftrace: Allow stealing pages from pipe buffer,
Yoshihiro YUNOMAE <=
- [Qemu-devel] [PATCH V2 5/6] virtio/console: Allocate scatterlist according to the current pipe size, Yoshihiro YUNOMAE, 2012/08/09
- [Qemu-devel] [PATCH V2 6/6] tools: Add guest trace agent as a user tool, Yoshihiro YUNOMAE, 2012/08/09
- Re: [Qemu-devel] [PATCH V2 0/6] virtio-trace: Support virtio-trace, Rusty Russell, 2012/08/12
- Re: [Qemu-devel] [PATCH V2 0/6] virtio-trace: Support virtio-trace, Amit Shah, 2012/08/21