[TFRC]: Migrate TX history to singly-linked list
The patch set migrates TFRC TX history to a singly-linked list (implementing a
suggestion by Arnaldo Carvalho de Melo) and prepares locking. Adding locking
is important, since receiver and sender write/read asynchronously on the
TX history.
This patch presents only the data structures, so that the remaining patches in
the patch set are mostly self-explanatory.
Signed-off-by: Gerrit Renker <gerrit@xxxxxxxxxxxxxx>
---
net/dccp/ccids/ccid3.h | 3 ++-
net/dccp/ccids/lib/packet_history.c | 2 ++
net/dccp/ccids/lib/packet_history.h | 30 +++++++++++++++++++++---------
3 files changed, 25 insertions(+), 10 deletions(-)
--- a/net/dccp/ccids/lib/packet_history.c
+++ b/net/dccp/ccids/lib/packet_history.c
@@ -41,6 +41,8 @@
/*
* Transmitter History Routines
*/
+DEFINE_RWLOCK(tfrc_tx_hist_lock);
+
struct dccp_tx_hist *dccp_tx_hist_new(const char *name)
{
struct dccp_tx_hist *hist = kmalloc(sizeof(*hist), GFP_ATOMIC);
--- a/net/dccp/ccids/lib/packet_history.h
+++ b/net/dccp/ccids/lib/packet_history.h
@@ -52,18 +52,30 @@
/*
* Transmitter History data structures and declarations
*/
-struct dccp_tx_hist_entry {
- struct list_head dccphtx_node;
- u64 dccphtx_seqno;
- struct timeval dccphtx_tstamp;
-};
+extern struct dccp_tx_hist *dccp_tx_hist_new(const char *name);
+extern void dccp_tx_hist_delete(struct dccp_tx_hist *hist);
-struct dccp_tx_hist {
- struct kmem_cache *dccptxh_slab;
+/**
+ * tfrc_tx_hist - Simple singly-linked TX history list
+ * @next: next oldest entry (LIFO order)
+ * @seqno: sequence number of this entry
+ * @stamp: send time of packet with sequence number @seqno
+ */
+struct tfrc_tx_hist {
+ struct tfrc_tx_hist *next;
+ u64 seqno;
+ ktime_t stamp;
};
-extern struct dccp_tx_hist *dccp_tx_hist_new(const char *name);
-extern void dccp_tx_hist_delete(struct dccp_tx_hist *hist);
+/**
+ * tfrc_tx_hist_head - Head of TX history
+ * @first: begin of the list
+ * @cache: where list entries are allocated from
+ */
+struct tfrc_tx_hist_head {
+ struct tfrc_tx_hist *first;
+ struct kmem_cache *cache;
+};
static inline struct dccp_tx_hist_entry *
dccp_tx_hist_entry_new(struct dccp_tx_hist *hist,
--- a/net/dccp/ccids/ccid3.h
+++ b/net/dccp/ccids/ccid3.h
@@ -40,6 +40,7 @@
#include <linux/time.h>
#include <linux/types.h>
#include <linux/tfrc.h>
+#include "lib/packet_history.h"
#include "../ccid.h"
/* Two seconds as per RFC 3448 4.2 */
@@ -111,7 +112,7 @@ struct ccid3_hc_tx_sock {
ktime_t ccid3hctx_t_ld;
ktime_t ccid3hctx_t_nom;
u32 ccid3hctx_delta;
- struct list_head ccid3hctx_hist;
+ struct tfrc_tx_hist_head ccid3hctx_hist;
struct ccid3_options_received ccid3hctx_options_received;
};
-
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