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authorFrancis Yan <francisyyan@gmail.com>2016-11-27 23:07:18 -0800
committerDavid S. Miller <davem@davemloft.net>2016-11-30 10:04:25 -0500
commit1c885808e45601b2b6f68b30ac1d999e10b6f606 (patch)
tree4878c60feb2769477239b63194ce5946129bcd75 /arch/m32r/include/uapi/asm/socket.h
parenttcp: export sender limits chronographs to TCP_INFO (diff)
downloadlinux-dev-1c885808e45601b2b6f68b30ac1d999e10b6f606.tar.xz
linux-dev-1c885808e45601b2b6f68b30ac1d999e10b6f606.zip
tcp: SOF_TIMESTAMPING_OPT_STATS option for SO_TIMESTAMPING
This patch exports the sender chronograph stats via the socket SO_TIMESTAMPING channel. Currently we can instrument how long a particular application unit of data was queued in TCP by tracking SOF_TIMESTAMPING_TX_SOFTWARE and SOF_TIMESTAMPING_TX_SCHED. Having these sender chronograph stats exported simultaneously along with these timestamps allow further breaking down the various sender limitation. For example, a video server can tell if a particular chunk of video on a connection takes a long time to deliver because TCP was experiencing small receive window. It is not possible to tell before this patch without packet traces. To prepare these stats, the user needs to set SOF_TIMESTAMPING_OPT_STATS and SOF_TIMESTAMPING_OPT_TSONLY flags while requesting other SOF_TIMESTAMPING TX timestamps. When the timestamps are available in the error queue, the stats are returned in a separate control message of type SCM_TIMESTAMPING_OPT_STATS, in a list of TLVs (struct nlattr) of types: TCP_NLA_BUSY_TIME, TCP_NLA_RWND_LIMITED, TCP_NLA_SNDBUF_LIMITED. Unit is microsecond. Signed-off-by: Francis Yan <francisyyan@gmail.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to '')
-rw-r--r--arch/m32r/include/uapi/asm/socket.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/m32r/include/uapi/asm/socket.h b/arch/m32r/include/uapi/asm/socket.h
index 5fe42fc7b6c5..5853f8e92c20 100644
--- a/arch/m32r/include/uapi/asm/socket.h
+++ b/arch/m32r/include/uapi/asm/socket.h
@@ -90,4 +90,6 @@
#define SO_CNX_ADVICE 53
+#define SCM_TIMESTAMPING_OPT_STATS 54
+
#endif /* _ASM_M32R_SOCKET_H */