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| author |   Eliezer Tamir <eliezer.tamir@linux.intel.com> | 2013-06-14 16:33:35 +0300 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2013-06-17 15:48:14 -0700 |
| commit | 9a3c71aa802499e0b1db2788ccc75a56c5f00555 (patch) | |
| tree | ac1284082bf9bdac09952fc437b594efff61b800 | |
| parent | net: change sysctl_net_ll_poll into an unsigned int (diff) | |
| download | linux-dev-9a3c71aa802499e0b1db2788ccc75a56c5f00555.tar.xz linux-dev-9a3c71aa802499e0b1db2788ccc75a56c5f00555.zip | |
net: convert low latency sockets to sched_clock()
Use sched_clock() instead of get_cycles().
We can use sched_clock() because we don't care much about accuracy.
Remove the dependency on X86_TSC
Signed-off-by: Eliezer Tamir <eliezer.tamir@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | include/net/ll_poll.h | 33 | ||||
| -rw-r--r-- | net/Kconfig | 1 |
2 files changed, 17 insertions, 17 deletions
diff --git a/include/net/ll_poll.h b/include/net/ll_poll.h index 44e2f707cb9f..6930cbd943e2 100644 --- a/include/net/ll_poll.h +++ b/include/net/ll_poll.h @@ -21,10 +21,6 @@ * e1000-devel Mailing List <e1000-devel@lists.sourceforge.net> */ -/* - * For now this depends on CONFIG_X86_TSC - */ - #ifndef _LINUX_NET_LL_POLL_H #define _LINUX_NET_LL_POLL_H @@ -40,13 +36,19 @@ extern unsigned int sysctl_net_ll_poll __read_mostly; #define LL_FLUSH_FAILED -1 #define LL_FLUSH_BUSY -2 -/* we don't mind a ~2.5% imprecision */ -#define TSC_MHZ (tsc_khz >> 10) - -static inline cycles_t ll_end_time(void) +/* we can use sched_clock() because we don't care much about precision + * we only care that the average is bounded + */ +static inline u64 ll_end_time(void) { - return (cycles_t)TSC_MHZ * ACCESS_ONCE(sysctl_net_ll_poll) - + get_cycles(); + u64 end_time = ACCESS_ONCE(sysctl_net_ll_poll); + + /* we don't mind a ~2.5% imprecision + * sysctl_net_ll_poll is a u_int so this can't overflow + */ + end_time = (end_time << 10) + sched_clock(); + + return end_time; } static inline bool sk_valid_ll(struct sock *sk) @@ -55,16 +57,15 @@ static inline bool sk_valid_ll(struct sock *sk) !need_resched() && !signal_pending(current); } -static inline bool can_poll_ll(cycles_t end_time) +static inline bool can_poll_ll(u64 end_time) { - return !time_after((unsigned long)get_cycles(), - (unsigned long)end_time); + return !time_after64(sched_clock(), end_time); } static inline bool sk_poll_ll(struct sock *sk, int nonblock) { - cycles_t end_time = ll_end_time(); const struct net_device_ops *ops; + u64 end_time = ll_end_time(); struct napi_struct *napi; int rc = false; @@ -117,7 +118,7 @@ static inline void sk_mark_ll(struct sock *sk, struct sk_buff *skb) #else /* CONFIG_NET_LL_RX_POLL */ -static inline cycles_t ll_end_time(void) +static inline u64 ll_end_time(void) { return 0; } @@ -140,7 +141,7 @@ static inline void sk_mark_ll(struct sock *sk, struct sk_buff *skb) { } -static inline bool can_poll_ll(cycles_t end_time) +static inline bool can_poll_ll(u64 end_time) { return false; } diff --git a/net/Kconfig b/net/Kconfig index d6a9ce6e1800..e591668fb38f 100644 --- a/net/Kconfig +++ b/net/Kconfig @@ -245,7 +245,6 @@ config NETPRIO_CGROUP config NET_LL_RX_POLL bool "Low Latency Receive Poll" - depends on X86_TSC default n ---help--- Support Low Latency Receive Queue Poll. |