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tap: minor code cleanup

PATCH In review Michael S. Tsirkin 2 participants 2 messages Feb 3, 2011 – Feb 8, 2011 Networking

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Michael S. Tsirkin

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#0 lore raw

PATCH 1/1 tap: minor code cleanup

remove a confusing comment.
TAP_DEFAULT_SNDBUF 0 is later translated to INT_MAX, so let's set that value directly.

Signed-off-by Michael S. Tsirkin <[email protected]>
---
 net/tap-linux.c |    7 +------
 1 files changed, 1 insertions(+), 6 deletions(-)
net/tap-linux.c +1 -6
index 00f84d4..b8c0f3b 100644
@@ -84,13 +84,8 @@ int tap_open(char *ifname, int ifname_size, int *vnet_hdr, int vnet_hdr_required
  * Unfortunately when it's enabled, and packets are sent
  * to other guests on the same host, the receiver
  * can lock up the transmitter indefinitely.
- *
- * To avoid packet loss, sndbuf should be set to a value lower than the tx
- * queue capacity of any destination network interface.
- * Ethernet NICs generally have txqueuelen=1000, so 1Mb is
- * a good value, given a 1500 byte MTU.
  */
-#define TAP_DEFAULT_SNDBUF 0
+#define TAP_DEFAULT_SNDBUF INT_MAX
 
 int tap_set_sndbuf(int fd, QemuOpts *opts)
 {
Signature · 1 line
1.7.3.2.91.g446ac
#1 lore raw
Quoted 18 lines · Michael S. Tsirkin

remove a confusing comment.
TAP_DEFAULT_SNDBUF 0 is later translated to INT_MAX, so let's set that value directly.

Signed-off-by Michael S. Tsirkin <[email protected]>
---
 net/tap-linux.c |    7 +------
 1 files changed, 1 insertions(+), 6 deletions(-)
net/tap-linux.c +0 -1
index 00f84d4..b8c0f3b 100644
@@ -84,13 +84,8 @@ int tap_open(char *ifname, int ifname_size, int *vnet_hdr, int vnet_hdr_required
  * Unfortunately when it's enabled, and packets are sent
  * to other guests on the same host, the receiver
  * can lock up the transmitter indefinitely.
- *

net/tap-linux.c int tap_open(char *ifname, int ifname_size, int *vnet_hdr, int vnet_hdr_required · line 91

Quoted 10 lines
net/tap-linux.c +1 -5
- * To avoid packet loss, sndbuf should be set to a value lower than the tx
- * queue capacity of any destination network interface.
- * Ethernet NICs generally have txqueuelen=1000, so 1Mb is
- * a good value, given a 1500 byte MTU.
  */
-#define TAP_DEFAULT_SNDBUF 0
+#define TAP_DEFAULT_SNDBUF INT_MAX
 
 int tap_set_sndbuf(int fd, QemuOpts *opts)
 {

Can't comment on whether the comment should stay or go, but what about tap_set_sndbuf()'s

    if (!sndbuf) {
        sndbuf = INT_MAX;
    }

Shouldn't that assign TAP_DEFAULT_SNDBUF now?