net: low latency Ethernet device polling
Subsystems (8)
v6 cover net: low latency Ethernet device polling
One more round of fixes.
Thank you all for your input.
-Eliezer
change log:
v6
- many small fixes suggested by Eric Dumazet:
data locality, typos, documentation
protect napi_hash insert/delete with a spinlock (napi_gen_id is no longer atomic_t since it's only accessed with the spinlock held.)
- added IPv6 TCP and UDP support (only minimally tested)
v5
- corrections suggested by Ben Hutchings:
fixed typos, moved the config option and sysctl value from IPv4 to net
- moved sk_mark_ll() to the protocol handlers
- removed global id mechanism, replaced with a hashed napi_id. based on code sample from Eric Dumazet
Note that ixgbe_free_q_vector() already waits an rcu grace period before freeing the q_vector, so nothing additional needs to be done when adding a call to napi_hash_del().
- simple poll/select support
v4
- removed separate config option for TCP as suggested Eric Dumazet.
- added linux mib counter for packets received through the low latency path, as suggested by Andi Kleen.
- re-allow module unloading, remove module param, use a global generation id instead to prevent the use of a stale napi pointer, as suggested by Eric Dumazet
- updated Documentation/networking/ip-sysctl.txt text
v3
- coding style changes suggested by Dave Miller
v2
- the sysctl knob is now in microseconds. The default value is now 0 (off).
- for now the code depends at configure time on CONFIG_I86_TSC
- the napi reference in struct skb is now a union with the dma cookie since the former is only used on RX and the latter on TX,
as suggested by Eric Dumazet.
- we do a better job at honoring non-blocking operations.
- removed busy-polling support for tcp_read_sock()
- remove dynamic disabling of GRO
- coding style fixes
- disallow unloading the device module after the feature has been used
Credit:
Jesse Brandeburg, Arun Chekhov Ilango, Julie Cummings, Alexander Duyck, Eric Geisler, Jason Neighbors, Yadong Li, Mike Polehn, Anil Vasudevan, Don Wood
Special thanks for finding bugs in earlier versions:
Willem de Bruijn and Andi Kleen
Thanks,
Eliezer
PATCH v6 1/5 net: add napi_id and hash
Adds a napi_id and a hashing mechanism to lookup a napi by id. This will be used by subsequent patches to implement low latency Ethernet device polling.
Based on a code sample by Eric Dumazet.
---
include/linux/netdevice.h | 29 ++++++++++++++++++++++++ net/core/dev.c | 54 +++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 83 insertions(+), 0 deletions(-)
include/linux/netdevice.h +29 -0
@@ -324,12 +324,15 @@ struct napi_struct {struct sk_buff *gro_list;struct sk_buff *skb;struct list_head dev_list; +struct hlist_node napi_hash_node; +unsigned int napi_id; };enum {NAPI_STATE_SCHED ,/* Poll is scheduled */ NAPI_STATE_DISABLE ,/* Disable pending */ NAPI_STATE_NPSVC ,/* Netpoll - don't dequeue from poll_list */ +NAPI_STATE_HASHED ,/* In NAPI hash */ };enum gro_result {
@@ -446,6 +449,32 @@ extern void __napi_complete(struct napi_struct *n);extern void napi_complete (struct napi_struct *n);/** +* napi_hash_add - add a NAPI to global hashtable +* @napi: napi context +* +* generate a new napi_id and store a @napi under it in napi_hash +*/ +extern void napi_hash_add (struct napi_struct *napi); + +/** +* napi_hash_del - remove a NAPI from global table +* @napi: napi context +* +* Warning: caller must observe rcu grace period +* before freeing memory containing @napi +*/ +extern void napi_hash_del (struct napi_struct *napi); + +/** +* napi_by_id - lookup a NAPI by napi_id +* @napi_id: hashed napi_id +* +* lookup @napi_id in napi_hash table +* must be called under rcu_read_lock() +*/ +extern struct napi_struct *napi_by_id (int napi_id); + +/** * napi_disable - prevent NAPI from scheduling * @n: napi context *
net/core/dev.c +54 -0
72 lines not on this page · raw message
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Re: [PATCH v6 net-next 1/5] net: add napi_id and hash
Quoted 7 lines · Eliezer Tamir
Adds a
napi_idand a hashing mechanism to lookup a napi by id. This will be used by subsequent patches to implement low latency Ethernet device polling.
Based on a code sample by Eric Dumazet.Signed-off-by Eliezer Tamir <[email protected]>---
OK this looks good enough for inclusion.
If a v7 ever is submitted, please add a 'static' for
static DEFINE_SPINLOCK(napi_hash_lock);
static unsigned int napi_gen_id;
static DEFINE_HASHTABLE(napi_hash, 8);
If David chose to apply v6, I'll submit a patch for this.
RE: [PATCH v6 net-next 1/5] net: add napi_id and hash
Quoted 1 line
Quoted 1 line
Adds a
napi_idand a hashing mechanism to lookup a napi by id.
Is this one of the places where the 'id' can be selected so that the 'hash' lookup never collides?
David
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RE: [PATCH v6 net-next 1/5] net: add napi_id and hash
Quoted 4 lines · David Laight
Quoted 1 line
Quoted 1 line
Adds a
napi_idand a hashing mechanism to lookup a napi by id.Is this one of the places where the 'id' can be selected so that the 'hash' lookup never collides?
Very few devices will ever call napi_hash_add()
[ Real NIC RX queues, not virtual devices ]
We use a hash table with 256 slots, the chance of collision is about 0%
Lets not over engineer the thing before its even used.
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Re: [PATCH v6 net-next 1/5] net: add napi_id and hash
In reply to Eric DumazetQuoted 9 lines · Eric Dumazet
Quoted 7 lines · Eliezer Tamir
Adds a
napi_idand a hashing mechanism to lookup a napi by id. This will be used by subsequent patches to implement low latency Ethernet device polling.
Based on a code sample by Eric Dumazet.Signed-off-by Eliezer Tamir <[email protected]>---
Quoted 8 lines
OK this looks good enough for inclusion.
If a v7 ever is submitted, please add a 'static' for
static
DEFINE_SPINLOCK(napi_hash_lock);
static unsigned intnapi_gen_id;
staticDEFINE_HASHTABLE(napi_hash, 8);
I will post a v7 along with the changes you suggested to 2/5, I will wait a bit to see if there are other things to fix.
Thanks,
Eliezer
Re: [PATCH v6 net-next 1/5] net: add napi_id and hash
In reply to Eliezer TamirQuoted 6 lines · Eliezer Tamir
Adds a
napi_idand a hashing mechanism to lookup a napi by id. This will be used by subsequent patches to implement low latency Ethernet device polling.
Based on a code sample by Eric Dumazet.Signed-off-by Eliezer Tamir <[email protected]>
[...]
Quoted 2 lines
net/core/dev.c +0
-0
[...]
Quoted 4 lines
net/core/dev.c +0
-0@@ -4136,6 +4143,53 @@ void napi_complete(struct napi_struct *n) }EXPORT_SYMBOL (napi_complete);
net/core/dev.c void napi_complete(struct napi_struct *n) · line 4155
Quoted 10 lines
net/core/dev.c +10
-0+void napi_hash_add (struct napi_struct *napi) +{ +if (!test_and_set_bit (NAPI_STATE_HASHED , &napi->state)) { + +spin_lock (&napi_hash_lock); + +/* 0 is not a valid id */ + napi->napi_id =0 ; +while (!napi->napi_id) + napi->napi_id = ++napi_gen_id;
Suppose we're loading/unloading one driver repeatedly while another one remains loaded the whole time. Then once napi_gen_id wraps around, the same ID can be assigned to multiple contexts.
So far as I can see, assigning the same ID twice will just make polling stop working for one of the NAPI contexts; I don't think it causes a crash. And it is exceedingly unlikely to happen in production. But if you're going to the trouble of handling wrap-around at all, you'd better handle this.
[...]
net/core/dev.c void napi_complete(struct napi_struct *n) · line 4182
Quoted 4 lines
net/core/dev.c +4
-0+/* must be called under rcu_read_lock(), as we dont take a reference */ +struct napi_struct *napi_by_id (int napi_id) +{ +unsigned int hash = napi_id %HASH_SIZE (napi_hash);
[...]
napi_id should be declared unsigned int here, as elsewhere. The division can't actually yield a negative result because HASH_SIZE() has type size_t and napi_id is promoted to match, but I had to go and look at hashtable.h to check that.
Ben.
Signature · 16 lines
Ben Hutchings, Staff Engineer, Solarflare Not speaking for my employer; that's the marketing department's job. They asked us to note that Solarflare product names are trademarked. ------------------------------------------------------------------------------ Introducing AppDynamics Lite, a free troubleshooting tool for Java/.NET Get 100% visibility into your production application - at no cost. Code-level diagnostics for performance bottlenecks with <2% overhead Download for free and get started troubleshooting in minutes. http://p.sf.net/sfu/appdyn_d2d_ap1 _______________________________________________ E1000-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/e1000-devel To learn more about Intel® Ethernet, visit http://communities.intel.com/community/wired
Re: [PATCH v6 net-next 1/5] net: add napi_id and hash
Quoted 16 lines · Ben Hutchings
net/core/dev.c void napi_complete(struct napi_struct *n) · line 4155
Quoted 10 lines · Eliezer Tamir
net/core/dev.c +10
-0+void napi_hash_add (struct napi_struct *napi) +{ +if (!test_and_set_bit (NAPI_STATE_HASHED , &napi->state)) { + +spin_lock (&napi_hash_lock); + +/* 0 is not a valid id */ + napi->napi_id =0 ; +while (!napi->napi_id) + napi->napi_id = ++napi_gen_id;Suppose we're loading/unloading one driver repeatedly while another one remains loaded the whole time. Then once
napi_gen_idwraps around, the same ID can be assigned to multiple contexts.
Quoted 5 lines
So far as I can see, assigning the same ID twice will just make polling stop working for one of the NAPI contexts; I don't think it causes a crash. And it is exceedingly unlikely to happen in production. But if you're going to the trouble of handling wrap-around at all, you'd better handle this.
OK
Quoted 11 lines
[...]
net/core/dev.c void napi_complete(struct napi_struct *n) · line 4182
Quoted 4 lines
net/core/dev.c +4
-0+/* must be called under rcu_read_lock(), as we dont take a reference */ +struct napi_struct *napi_by_id (int napi_id) +{ +unsigned int hash = napi_id %HASH_SIZE (napi_hash);[...]
napi_idshould be declared unsigned int here, as elsewhere. The division can't actually yield a negative result becauseHASH_SIZE()has typesize_tandnapi_idis promoted to match, but I had to go and look athashtable.hto check that.
Good catch,
Thanks,
Eliezer
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PATCH v6 2/5 net: implement support for low latency socket polling
In reply to Eliezer TamirAdds a new ndo_ll_poll method and the code that supports and uses it. This method can be used by low latency applications to busy poll Ethernet device queues directly from the socket code. The value of sysctl_net_ll_poll controls how many microseconds to poll. Set to zero to disable.
---
Documentation/sysctl/net.txt | 7 ++ fs/select.c | 7 ++ include/linux/netdevice.h | 3 + include/linux/skbuff.h | 8 ++- include/net/ll_poll.h | 126 ++++++++++++++++++++++++++++++++++++++++++ include/net/sock.h | 4 + include/uapi/linux/snmp.h | 1 net/Kconfig | 12 ++++ net/core/datagram.c | 4 + net/core/skbuff.c | 4 + net/core/sock.c | 6 ++ net/core/sysctl_net_core.c | 10 +++ net/ipv4/proc.c | 1 net/ipv4/udp.c | 6 ++ net/ipv6/udp.c | 6 ++ net/socket.c | 16 +++++ 16 files changed, 216 insertions(+), 5 deletions(-) create mode 100644 include/net/ll_poll.h
Documentation/sysctl/net.txt +7 -0
@@ -50,6 +50,13 @@ The maximum number of packets that kernel can handle on a NAPI interrupt, it's a Per-CPU variable. Default: 64 +low_latency_poll +---------------- +Low latency busy poll timeout. (needs CONFIG_NET_LL_RX_POLL) +Approximate time in us to spin waiting for packets on the device queue. +Recommended value is 50. May increase power usage. +Default: 0 (off) + rmem_default ------------
fs/select.c +7 -0
@@ -27,6 +27,7 @@#include <linux/rcupdate.h> #include <linux/hrtimer.h> #include <linux/sched/rt.h> +#include <net/ll_poll.h> #include <asm/uaccess.h>
@@ -400,6 +401,7 @@ int do_select(int n, fd_set_bits *fds, struct timespec *end_time)poll_table *wait;int retval, i, timed_out =0 ;unsigned long slack =0 ; +unsigned long ll_time =ll_end_time ();rcu_read_lock (); retval =max_select_fd (n, fds);
@@ -486,6 +488,8 @@ int do_select(int n, fd_set_bits *fds, struct timespec *end_time)break ; } +if (can_poll_ll (ll_time)) +continue ;/* * If this is the first loop and we have a timeout * given, then we convert to ktime_t and set the to
@@ -750,6 +754,7 @@ static int do_poll(unsigned int nfds, struct poll_list *list,ktime_t expire, *to =NULL ;int timed_out =0 , count =0 ;unsigned long slack =0 ; +unsigned long ll_time =ll_end_time ();/* Optimise the no-wait case */ if (end_time && !end_time->tv_sec && !end_time->tv_nsec) {
@@ -795,6 +800,8 @@ static int do_poll(unsigned int nfds, struct poll_list *list,if (count || timed_out)break ; +if (can_poll_ll (ll_time)) +continue ;/* * If this is the first loop and we have a timeout * given, then we convert to ktime_t and set the to
include/linux/netdevice.h +3 -0
@@ -972,6 +972,9 @@ struct net_device_ops { gfp_t gfp);void (*ndo_netpoll_cleanup)(struct net_device *dev);#endif +#ifdef CONFIG_NET_LL_RX_POLL +int (*ndo_ll_poll)(struct napi_struct *dev); +#endif int (*ndo_set_vf_mac)(struct net_device *dev,int queue,u8 *mac); int (*ndo_set_vf_vlan)(struct net_device *dev,
include/linux/skbuff.h +6 -2
@@ -386,6 +386,7 @@ typedef unsigned char *sk_buff_data_t;* @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS * @dma_cookie: a cookie to one of several possible DMA operations * done by skb DMA functions +* @napi_id: id of the NAPI struct this skb came from * @secmark: security marking * @mark: Generic packet mark * @dropcount: total number of sk_receive_queue overflows
@@ -500,8 +501,11 @@ struct sk_buff {/* 7/9 bit hole (depending on ndisc_nodetype presence) */ kmemcheck_bitfield_end (flags2); -#ifdef CONFIG_NET_DMA -dma_cookie_t dma_cookie; +#if definedCONFIG_NET_DMA || definedCONFIG_NET_LL_RX_POLL +union { +unsigned int napi_id; +dma_cookie_t dma_cookie; + };#endif #ifdef CONFIG_NETWORK_SECMARK __u32 secmark;
include/net/ll_poll.h new file +126 -0
126 lines not on this page · raw message
include/net/sock.h +4 -0
@@ -229,6 +229,7 @@ struct cg_proto;* @sk_omem_alloc: "o" is "option" or "other" * @sk_wmem_queued: persistent queue size * @sk_forward_alloc: space allocated forward +* @sk_napi_id: id of the last napi context to receive data for sk * @sk_allocation: allocation mode * @sk_sndbuf: size of send buffer in bytes * @sk_flags: %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE,
@@ -325,6 +326,9 @@ struct sock {#ifdef CONFIG_RPS __u32 sk_rxhash;#endif +#ifdef CONFIG_NET_LL_RX_POLL +unsigned int sk_napi_id; +#endif atomic_t sk_drops;int sk_rcvbuf;
include/uapi/linux/snmp.h +1 -0
@@ -253,6 +253,7 @@ enumLINUX_MIB_TCPFASTOPENLISTENOVERFLOW ,/* TCPFastOpenListenOverflow */ LINUX_MIB_TCPFASTOPENCOOKIEREQD ,/* TCPFastOpenCookieReqd */ LINUX_MIB_TCPSPURIOUS_RTX_HOSTQUEUES ,/* TCPSpuriousRtxHostQueues */ +LINUX_MIB_LOWLATENCYRXPACKETS ,/* LowLatencyRxPackets */ __LINUX_MIB_MAX };
net/Kconfig +12 -0
@@ -243,6 +243,18 @@ config NETPRIO_CGROUP Cgroup subsystem for use in assigning processes to network priorities on a per-interface basis +config NET_LL_RX_POLL + bool "Low Latency Receive Poll" + depends on X86_TSC + default n + ---help--- + Support Low Latency Receive Queue Poll. + (For network card drivers which support this option.) + When waiting for data in read or poll call directly into the the device driver + to flush packets which may be pending on the device queues into the stack. + + If unsure, say N. + config BQL boolean depends on SYSFS
net/core/datagram.c +4 -0
@@ -56,6 +56,7 @@#include <net/sock.h> #include <net/tcp_states.h> #include <trace/events/skb.h> +#include <net/ll_poll.h> /* * Is a socket 'connection oriented' ?
@@ -207,6 +208,9 @@ struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned int flags, }spin_unlock_irqrestore (&queue->lock, cpu_flags); +if (sk_valid_ll (sk) &&sk_poll_ll (sk, flags &MSG_DONTWAIT )) +continue ; +/* User doesn't want to wait */ error = -EAGAIN ;if (!timeo)
net/core/skbuff.c +4 -0
@@ -739,6 +739,10 @@ static void __copy_skb_header(struct sk_buff *new, const struct sk_buff *old) new->vlan_tci = old->vlan_tci;skb_copy_secmark (new, old); + +#ifdef CONFIG_NET_LL_RX_POLL + new->napi_id = old->napi_id; +#endif }/*
net/core/sock.c +6 -0
@@ -139,6 +139,8 @@#include <net/tcp.h> #endif +#include <net/ll_poll.h> +static DEFINE_MUTEX (proto_list_mutex);static LIST_HEAD (proto_list);
@@ -2284,6 +2286,10 @@ void sock_init_data(struct socket *sock, struct sock *sk) sk->sk_stamp =ktime_set (-1L ,0 ); +#ifdef CONFIG_NET_LL_RX_POLL + sk->sk_napi_id =0 ; +#endif +/* * Before updating sk_refcnt, we must commit prior changes to memory * (Documentation/RCU/rculist_nulls.txt for details)
net/core/sysctl_net_core.c +10 -0
@@ -19,6 +19,7 @@#include <net/ip.h> #include <net/sock.h> #include <net/net_ratelimit.h> +#include <net/ll_poll.h> static int one =1 ;
@@ -284,6 +285,15 @@ static struct ctl_table net_core_table[] = { .proc_handler = flow_limit_table_len_sysctl }, #endif /* CONFIG_NET_FLOW_LIMIT */ +#ifdef CONFIG_NET_LL_RX_POLL + { + .procname = "low_latency_poll", + .data = &sysctl_net_ll_poll, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec + }, +#endif #endif /* CONFIG_NET */ { .procname = "netdev_budget",
net/ipv4/proc.c +1 -0
@@ -273,6 +273,7 @@ static const struct snmp_mib snmp4_net_list[] = {SNMP_MIB_ITEM ("TCPFastOpenListenOverflow" ,LINUX_MIB_TCPFASTOPENLISTENOVERFLOW ),SNMP_MIB_ITEM ("TCPFastOpenCookieReqd" ,LINUX_MIB_TCPFASTOPENCOOKIEREQD ),SNMP_MIB_ITEM ("TCPSpuriousRtxHostQueues" ,LINUX_MIB_TCPSPURIOUS_RTX_HOSTQUEUES ), +SNMP_MIB_ITEM ("LowLatencyRxPackets" ,LINUX_MIB_LOWLATENCYRXPACKETS ), SNMP_MIB_SENTINEL };
net/ipv4/udp.c +5 -1
@@ -109,6 +109,7 @@#include <trace/events/udp.h> #include <linux/static_key.h> #include <trace/events/skb.h> +#include <net/ll_poll.h> #include "udp_impl.h" struct udp_table udp_table__read_mostly ;
@@ -1709,7 +1710,10 @@ int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, sk =__udp4_lib_lookup_skb (skb, uh->source, uh->dest, udptable);if (sk !=NULL ) { -int ret =udp_queue_rcv_skb (sk, skb); +int ret; + +sk_mark_ll (sk, skb); + ret =udp_queue_rcv_skb (sk, skb);sock_put (sk);/* a return value > 0 means to resubmit the input, but
net/ipv6/udp.c +5 -1
@@ -46,6 +46,7 @@#include <net/ip6_checksum.h> #include <net/xfrm.h> #include <net/inet6_hashtables.h> +#include <net/ll_poll.h> #include <linux/proc_fs.h> #include <linux/seq_file.h>
@@ -841,7 +842,10 @@ int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,*/ sk =__udp6_lib_lookup_skb (skb, uh->source, uh->dest, udptable);if (sk !=NULL ) { -int ret =udpv6_queue_rcv_skb (sk, skb); +int ret; + +sk_mark_ll (sk, skb); + ret =udpv6_queue_rcv_skb (sk, skb);sock_put (sk);/* a return value > 0 means to resubmit the input, but
net/socket.c +15 -1
@@ -104,6 +104,12 @@#include <linux/route.h> #include <linux/sockios.h> #include <linux/atalk.h> +#include <net/ll_poll.h> + +#ifdef CONFIG_NET_LL_RX_POLL +int sysctl_net_ll_poll__read_mostly ; +EXPORT_SYMBOL_GPL (sysctl_net_ll_poll); +#endif static int sock_no_open (struct inode *irrelevant,struct file *dontcare); static ssize_t sock_aio_read(struct kiocb *iocb, const struct iovec *iov,
@@ -1142,13 +1148,21 @@ EXPORT_SYMBOL(sock_create_lite);/* No kernel lock held - perfect */ static unsigned int sock_poll (struct file *file,poll_table *wait) { +unsigned int poll_result;struct socket *sock;/* * We can't return errors to poll, so it's either yes or no. */ sock = file->private_data; -return sock->ops->poll (file, sock, wait); + + poll_result = sock->ops->poll (file, sock, wait); + +if (!(poll_result & (POLLRDNORM |POLLERR |POLLRDHUP |POLLHUP )) && +sk_valid_ll (sock->sk) &&sk_poll_ll (sock->sk,1 )) + poll_result = sock->ops->poll (file, sock,NULL ); + +return poll_result; }static int sock_mmap (struct file *file,struct vm_area_struct *vma)
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Re: [PATCH v6 net-next 2/5] net: implement support for low latency socket polling
include/net/ll_poll.h line 36
Quoted 10 lines · Eliezer Tamir
include/net/ll_poll.h new file +10
-0+/* we don't mind a ~2.5% imprecision */ +#define TSC_MHZ (tsc_khz >> 10) + +static inline unsigned long ll_end_time (void ) +{ +return TSC_MHZ *ACCESS_ONCE (sysctl_net_ll_poll) +get_cycles (); +}static inline unsigned long ll_end_time (void ) +{ +return TSC_MHZ *ACCESS_ONCE (sysctl_net_ll_poll) +get_cycles (); +}
This can overflow.
Multiply is giving 32bits, as tsc_khz is an int, and sysctl_net_ll_poll is an int.
unsigned long sysctl_net_ll_poll ?
Also, if we want this to work on i386, the correct type to use for ll_end_time(void) would be cycles_t
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RE: [PATCH v6 net-next 2/5] net: implement support for low latency socket polling
Quoted 2 lines
include/net/ll_poll.h line 25
Quoted 2 lines
include/net/ll_poll.h new file +2
-0+/* we don't mind a ~2.5% imprecision */ +#define TSC_MHZ (tsc_khz >> 10)
Wouldn't (tsc_khz << 10) be better?
David
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RE: [PATCH v6 net-next 2/5] net: implement support for low latency socket polling
Quoted 4 lines · David Laight
Quoted 2 lines
include/net/ll_poll.h line 25
Quoted 2 lines
include/net/ll_poll.h new file +2
-0+/* we don't mind a ~2.5% imprecision */ +#define TSC_MHZ (tsc_khz >> 10)Wouldn't (
tsc_khz<< 10) be better?
We want number of cycles per usec.
Your formula gives number of cycles per 1.024 second.
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Re: [PATCH v6 net-next 2/5] net: implement support for low latency socket polling
In reply to Eric DumazetQuoted 9 lines · Eric Dumazet
include/net/ll_poll.h line 30
Quoted 4 lines · Eliezer Tamir
include/net/ll_poll.h new file +4
-0+static inline unsigned long ll_end_time (void ) +{ +return TSC_MHZ *ACCESS_ONCE (sysctl_net_ll_poll) +get_cycles (); +}This can overflow.
Quoted 4 lines
Multiply is giving 32bits, as
tsc_khzis an int, andsysctl_net_ll_pollis an int.unsigned long
sysctl_net_ll_poll?
OK
Quoted 2 lines
Also, if we want this to work on i386, the correct type to use for
ll_end_time(void)would becycles_t
OK
I would be really surprised if someone uses this on an i386, but I guess you never know.
Thanks!
-Eliezer
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Re: [PATCH v6 net-next 2/5] net: implement support for low latency socket polling
Hi Eliezer,
(If I'm too late then a future note...)
Why make polling a system-wide configuration?
Wouldn't it make more sense to implement a sock option?
An even better solution might be aggregation/combination of both types of configurations.
-- Yaniv Sa'ar
Quoted 30 lines · Eliezer Tamir
Quoted 2 lines · Eric Dumazet
On Wed, 2013-05-29 at 09:39 +0300, Eliezer Tamir wrote:
+static inline unsigned long
ll_end_time(void)Quoted 8 lines
Quoted 5 lines
(quoted diff) +2
-0+{ + return TSC_MHZ * ACCESS_ONCE(sysctl_net_ll_**poll) +
get_cycles();
+}This can overflow.
Quoted 5 lines
Multiply is giving 32bits, as
tsc_khzis an int, andsysctl_net_ll_pollis an int.unsigned long
sysctl_net_ll_poll?OK
Also, if we want this to work on i386, the correct type to use for
Quoted 2 lines
ll_end_time(void)would becycles_tOK
I would be really surprised if someone uses this on an i386, but I guess you never know.
Quoted 9 lines
Thanks!
-Eliezer--
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Re: [PATCH v6 net-next 2/5] net: implement support for low latency socket polling
Quoted 9 lines · yaniv saar
Hi Eliezer,
(If I'm too late then a future note...)
Why make polling a system-wide configuration?
Wouldn't it make more sense to implement a sock option?
An even better solution might be aggregation/combination of both types of configurations.-- Yaniv Sa'ar
We plan on adding a socket option in the future.
-Eliezer
Re: [PATCH v6 net-next 2/5] net: implement support for low latency socket polling
In reply to Eliezer TamirQuoted 4 lines · Eliezer Tamir
Adds a new
ndo_ll_pollmethod and the code that supports and uses it. This method can be used by low latency applications to busy poll Ethernet device queues directly from the socket code. The value ofsysctl_net_ll_pollcontrols how many microseconds to poll. Set to zero to disable.
Unlike with TCP sockets, UDP sockets may receive packets from multiple sources and hence the receiving context may be steered to be executed on different cores through RSS or other Flow-Steering HW mechanisms which could mean different napi contexts for the same socket, is that a problem here? what's the severity?
Or.
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Re: [PATCH v6 net-next 2/5] net: implement support for low latency socket polling
Hi Eliezer,
(If I'm too late then a future note...)
Why make polling a system-wide configuration?
Wouldn't it make more sense to implement a sock option?
An even better solution might be aggregation/combination of both types of configurations.
-- Yaniv Sa'ar
Quoted 19 lines · Or Gerlitz
Quoted 4 lines · Eliezer Tamir
Adds a new
ndo_ll_pollmethod and the code that supports and uses it. This method can be used by low latency applications to busy poll Ethernet device queues directly from the socket code. The value ofsysctl_net_ll_pollcontrols how many microseconds to poll. Set to zero to disable.Unlike with TCP sockets, UDP sockets may receive packets from multiple sources and hence the receiving context may be steered to be executed on different cores through RSS or other Flow-Steering HW mechanisms which could mean different napi contexts for the same socket, is that a problem here? what's the severity?
Or.
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Re: [PATCH v6 net-next 2/5] net: implement support for low latency socket polling
In reply to Or GerlitzQuoted 7 lines · Or Gerlitz
Quoted 4 lines · Eliezer Tamir
Adds a new
ndo_ll_pollmethod and the code that supports and uses it. This method can be used by low latency applications to busy poll Ethernet device queues directly from the socket code. The value ofsysctl_net_ll_pollcontrols how many microseconds to poll. Set to zero to disable.
Quoted 5 lines
Unlike with TCP sockets, UDP sockets may receive packets from multiple sources and hence the receiving context may be steered to be executed on different cores through RSS or other Flow-Steering HW mechanisms which could mean different napi contexts for the same socket, is that a problem here? what's the severity?
Nothing will break if you poll on the wrong queue.
Your data will come through normal NAPI processing of the right queue.
One of the things we plan on adding in the next version is a more fine grained control over which sockets get to busy poll.
-Eliezer
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Re: [PATCH v6 net-next 2/5] net: implement support for low latency socket polling
Quoted 10 lines · Eliezer Tamir
Quoted 5 lines · Or Gerlitz
Unlike with TCP sockets, UDP sockets may receive packets from multiple sources and hence the receiving context may be steered to be executed on different cores through RSS or other Flow-Steering HW mechanisms which could mean different napi contexts for the same socket, is that a problem here? what's the severity?
Nothing will break if you poll on the wrong queue.
Your data will come through normal NAPI processing of the right queue.
Can you elaborate a little further, why you call this "wrong" and "right"?
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Re: [PATCH v6 net-next 2/5] net: implement support for low latency socket polling
Quoted 9 lines · Or Gerlitz
Quoted 7 lines · Eliezer Tamir
Quoted 5 lines · Or Gerlitz
Unlike with TCP sockets, UDP sockets may receive packets from multiple sources and hence the receiving context may be steered to be executed on different cores through RSS or other Flow-Steering HW mechanisms which could mean different napi contexts for the same socket, is that a problem here? what's the severity?
Quoted 5 lines
Quoted 2 lines
Nothing will break if you poll on the wrong queue.
Your data will come through normal NAPI processing of the right queue.Can you elaborate a little further, why you call this "wrong" and "right"? --
This definitely need some documentation, because before llpoll, device RX path was serviced by the cpu receiving the harwdare interrupt.
So the "wrong" queue could add false sharing, and wrong NUMA allocations.
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Re: [PATCH v6 net-next 2/5] net: implement support for low latency socket polling
Quoted 13 lines · Eric Dumazet
Quoted 12 lines · Or Gerlitz
Quoted 10 lines · Eliezer Tamir
Quoted 5 lines · Or Gerlitz
Unlike with TCP sockets, UDP sockets may receive packets from multiple sources and hence the receiving context may be steered to be executed on different cores through RSS or other Flow-Steering HW mechanisms which could mean different napi contexts for the same socket, is that a problem here? what's the severity?
Nothing will break if you poll on the wrong queue.
Your data will come through normal NAPI processing of the right queue.
Quoted 8 lines
Quoted 2 lines
Can you elaborate a little further, why you call this "wrong" and "right"? --
This definitely need some documentation, because before llpoll, device RX path was serviced by the cpu receiving the harwdare interrupt.
So the "wrong" queue could add false sharing, and wrong NUMA allocations.
Yes,
To work properly when you have more than one NUMA node, you have to have packet steering set up, either by your NIC or by HW accelerated RFS.
I would like to add a short writeup of the design and suggested configuration. Where should it go?
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Re: [PATCH v6 net-next 2/5] net: implement support for low latency socket polling
In reply to Or GerlitzQuoted 9 lines · Or Gerlitz
Quoted 7 lines · Eliezer Tamir
Quoted 5 lines · Or Gerlitz
Unlike with TCP sockets, UDP sockets may receive packets from multiple sources and hence the receiving context may be steered to be executed on different cores through RSS or other Flow-Steering HW mechanisms which could mean different napi contexts for the same socket, is that a problem here? what's the severity?
Quoted 4 lines
Quoted 2 lines
Nothing will break if you poll on the wrong queue.
Your data will come through normal NAPI processing of the right queue.Can you elaborate a little further, why you call this "wrong" and "right"?
Right == the queue the packets arrive on.
Wrong == any other queue.
BTW, if you have an application that receives UDP data to an unbound socket, wouldn't it be better in any case to steer all of the incoming packets for this UDP socket to a single queue disregarding the source address? (Can't your hardware do that?)
The general approach is that userspace needs to make sure that threads, connections and IRQs are bound to the right CPUs.
-Eliezer
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Re: [PATCH v6 net-next 2/5] net: implement support for low latency socket polling
In reply to Or GerlitzQuoted 7 lines · Or Gerlitz
Quoted 4 lines · Eliezer Tamir
Adds a new
ndo_ll_pollmethod and the code that supports and uses it. This method can be used by low latency applications to busy poll Ethernet device queues directly from the socket code. The value ofsysctl_net_ll_pollcontrols how many microseconds to poll. Set to zero to disable.
Quoted 5 lines
Unlike with TCP sockets, UDP sockets may receive packets from multiple sources and hence the receiving context may be steered to be executed on different cores through RSS or other Flow-Steering HW mechanisms which could mean different napi contexts for the same socket, is that a problem here? what's the severity?
Maybe ARFS could be extended so the driver can tell whether a UDP socket it's steering for is connected or not. Then for disconnected sockets the driver can use a filter that only matches destination address. (Though that's probably undesirable if the socket has SO_REUSEPORT set.)
Ben.
Signature · 16 lines
Ben Hutchings, Staff Engineer, Solarflare Not speaking for my employer; that's the marketing department's job. They asked us to note that Solarflare product names are trademarked. ------------------------------------------------------------------------------ Introducing AppDynamics Lite, a free troubleshooting tool for Java/.NET Get 100% visibility into your production application - at no cost. Code-level diagnostics for performance bottlenecks with <2% overhead Download for free and get started troubleshooting in minutes. http://p.sf.net/sfu/appdyn_d2d_ap1 _______________________________________________ E1000-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/e1000-devel To learn more about Intel® Ethernet, visit http://communities.intel.com/community/wired
PATCH v6 3/5 tcp: add TCP support for low latency receive poll.
In reply to Eliezer TamirAdds busy-poll support for TCP.
Copy the napi_id from an incomming skb to the sk in tcp_v[46]_rcv(). when there is no data in the socket we busy-poll in tcp_recvmsg(). This is a good example of how to add busy-poll support to new protocols.
---
net/ipv4/tcp.c | 5 +++++ net/ipv4/tcp_ipv4.c | 2 ++ net/ipv6/tcp_ipv6.c | 2 ++ 3 files changed, 9 insertions(+), 0 deletions(-)
net/ipv4/tcp.c +5 -0
@@ -279,6 +279,7 @@#include <asm/uaccess.h> #include <asm/ioctls.h> +#include <net/ll_poll.h> int sysctl_tcp_fin_timeout__read_mostly =TCP_FIN_TIMEOUT ;
@@ -1551,6 +1552,10 @@ int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,struct sk_buff *skb;u32 urg_hole =0 ; +if (sk_valid_ll (sk) &&skb_queue_empty (&sk->sk_receive_queue) + && (sk->sk_state ==TCP_ESTABLISHED )) +sk_poll_ll (sk, nonblock); +lock_sock (sk); err = -ENOTCONN ;
net/ipv4/tcp_ipv4.c +2 -0
@@ -75,6 +75,7 @@#include <net/netdma.h> #include <net/secure_seq.h> #include <net/tcp_memcontrol.h> +#include <net/ll_poll.h> #include <linux/inet.h> #include <linux/ipv6.h>
@@ -2011,6 +2012,7 @@ process:if (sk_filter (sk, skb)) goto discard_and_relse; +sk_mark_ll (sk, skb); skb->dev =NULL ;bh_lock_sock_nested (sk);
net/ipv6/tcp_ipv6.c +2 -0
@@ -63,6 +63,7 @@#include <net/inet_common.h> #include <net/secure_seq.h> #include <net/tcp_memcontrol.h> +#include <net/ll_poll.h> #include <asm/uaccess.h>
@@ -1498,6 +1499,7 @@ process:if (sk_filter (sk, skb)) goto discard_and_relse; +sk_mark_ll (sk, skb); skb->dev =NULL ;bh_lock_sock_nested (sk);
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Re: [PATCH v6 net-next 3/5] tcp: add TCP support for low latency receive poll.
Quoted 9 lines · Eliezer Tamir
Adds busy-poll support for TCP.
Copy thenapi_idfrom an incomming skb to the sk in tcp_v[46]_rcv(). when there is no data in the socket we busy-poll intcp_recvmsg(). This is a good example of how to add busy-poll support to new protocols.Signed-off-by Alexander Duyck <[email protected]>Signed-off-by Jesse Brandeburg <[email protected]>Tested-by Willem de Bruijn <[email protected]>Signed-off-by Eliezer Tamir <[email protected]>
Quoted 6 lines
---
net/ipv4/tcp.c | 5 +++++ net/ipv4/tcp_ipv4.c | 2 ++ net/ipv6/tcp_ipv6.c | 2 ++ 3 files changed, 9 insertions(+), 0 deletions(-)
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PATCH v6 4/5 ixgbe: Add support for ndo_ll_poll
In reply to Eliezer TamirAdd the ixgbe driver code implementing ndo_ll_poll. It should be easy for other drivers to do something similar in order to enable support for CONFIG_NET_LL_RX_POLL
---
drivers/net/ethernet/intel/ixgbe/ixgbe.h | 120 +++++++++++++++++++++++++ drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c | 2 drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 63 +++++++++++-- 3 files changed, 177 insertions(+), 8 deletions(-)
drivers/net/ethernet/intel/ixgbe/ixgbe.h +120 -0
@@ -52,6 +52,8 @@#include <linux/dca.h> #endif +#include <net/ll_poll.h> +/* common prefix used by pr_<> macros */ #undef pr_fmt#define pr_fmt (fmt) KBUILD_MODNAME ": " fmt
@@ -356,9 +358,127 @@ struct ixgbe_q_vector {struct rcu_head rcu;/* to avoid race with update stats on free */ char name[IFNAMSIZ +9 ]; +#ifdef CONFIG_NET_LL_RX_POLL +unsigned int state; +#define IXGBE_QV_STATE_IDLE 0 +#define IXGBE_QV_STATE_NAPI 1/* NAPI owns this QV */ +#define IXGBE_QV_STATE_POLL 2/* poll owns this QV */ +#define IXGBE_QV_LOCKED (IXGBE_QV_STATE_NAPI | IXGBE_QV_STATE_POLL) +#define IXGBE_QV_STATE_NAPI_YIELD 4/* NAPI yielded this QV */ +#define IXGBE_QV_STATE_POLL_YIELD 8/* poll yielded this QV */ +#define IXGBE_QV_YIELD (IXGBE_QV_STATE_NAPI_YIELD | IXGBE_QV_STATE_POLL_YIELD) +#define IXGBE_QV_USER_PEND (IXGBE_QV_STATE_POLL | IXGBE_QV_STATE_POLL_YIELD) +spinlock_t lock; +#endif /* CONFIG_NET_LL_RX_POLL */ +/* for dynamic allocation of rings associated with this q_vector */ struct ixgbe_ring ring[0 ]____cacheline_internodealigned_in_smp ; }; +#ifdef CONFIG_NET_LL_RX_POLL +static inline void ixgbe_qv_init_lock (struct ixgbe_q_vector *q_vector) +{ + +spin_lock_init (&q_vector->lock); + q_vector->state =IXGBE_QV_STATE_IDLE ; +} + +/* called from the device poll rutine to get ownership of a q_vector */ +static inline int ixgbe_qv_lock_napi (struct ixgbe_q_vector *q_vector) +{ +int rc = true; +spin_lock (&q_vector->lock); +if (q_vector->state &IXGBE_QV_LOCKED ) { +WARN_ON (q_vector->state &IXGBE_QV_STATE_NAPI ); + q_vector->state |=IXGBE_QV_STATE_NAPI_YIELD ; + rc = false; + }else +/* we don't care if someone yielded */ + q_vector->state =IXGBE_QV_STATE_NAPI ; +spin_unlock (&q_vector->lock); +return rc; +} + +/* returns true is someone tried to get the qv while napi had it */ +static inline int ixgbe_qv_unlock_napi (struct ixgbe_q_vector *q_vector) +{ +int rc = false; +spin_lock (&q_vector->lock); +WARN_ON (q_vector->state & (IXGBE_QV_STATE_POLL | +IXGBE_QV_STATE_NAPI_YIELD )); + +if (q_vector->state &IXGBE_QV_STATE_POLL_YIELD ) + rc = true; + q_vector->state =IXGBE_QV_STATE_IDLE ; +spin_unlock (&q_vector->lock); +return rc; +} + +/* called from ixgbe_low_latency_poll() */ +static inline int ixgbe_qv_lock_poll (struct ixgbe_q_vector *q_vector) +{ +int rc = true; +spin_lock_bh (&q_vector->lock); +if ((q_vector->state &IXGBE_QV_LOCKED )) { + q_vector->state |=IXGBE_QV_STATE_POLL_YIELD ; + rc = false; + }else +/* preserve yield marks */ + q_vector->state |=IXGBE_QV_STATE_POLL ; +spin_unlock_bh (&q_vector->lock); +return rc; +} + +/* returns true if someone tried to get the qv while it was locked */ +static inline int ixgbe_qv_unlock_poll (struct ixgbe_q_vector *q_vector) +{ +int rc = false; +spin_lock_bh (&q_vector->lock); +WARN_ON (q_vector->state & (IXGBE_QV_STATE_NAPI )); + +if (q_vector->state &IXGBE_QV_STATE_POLL_YIELD ) + rc = true; + q_vector->state =IXGBE_QV_STATE_IDLE ; +spin_unlock_bh (&q_vector->lock); +return rc; +} + +/* true if a socket is polling, even if it did not get the lock */ +static inline int ixgbe_qv_ll_polling (struct ixgbe_q_vector *q_vector) +{ +WARN_ON (!(q_vector->state &IXGBE_QV_LOCKED )); +return q_vector->state &IXGBE_QV_USER_PEND ; +} +#else /* CONFIG_NET_LL_RX_POLL */ +static inline void ixgbe_qv_init_lock (struct ixgbe_q_vector *q_vector) +{ +} + +static inline int ixgbe_qv_lock_napi (struct ixgbe_q_vector *q_vector) +{ +return true; +} + +static inline int ixgbe_qv_unlock_napi (struct ixgbe_q_vector *q_vector) +{ +return false; +} + +static inline int ixgbe_qv_lock_poll (struct ixgbe_q_vector *q_vector) +{ +return false; +} + +static inline int ixgbe_qv_unlock_poll (struct ixgbe_q_vector *q_vector) +{ +return false; +} + +static inline int ixgbe_qv_ll_polling (struct ixgbe_q_vector *q_vector) +{ +return false; +} +#endif /* CONFIG_NET_LL_RX_POLL */ +#ifdef CONFIG_IXGBE_HWMON #define IXGBE_HWMON_TYPE_LOC 0
drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c +2 -0
@@ -811,6 +811,7 @@ static int ixgbe_alloc_q_vector(struct ixgbe_adapter *adapter,/* initialize NAPI */ netif_napi_add (adapter->netdev, &q_vector->napi, ixgbe_poll,64 ); +napi_hash_add (&q_vector->napi);/* tie q_vector and adapter together */ adapter->q_vector[v_idx] = q_vector;
@@ -931,6 +932,7 @@ static void ixgbe_free_q_vector(struct ixgbe_adapter *adapter, int v_idx) adapter->rx_ring[ring->queue_index] =NULL ; adapter->q_vector[v_idx] =NULL ; +napi_hash_del (&q_vector->napi);netif_napi_del (&q_vector->napi);/*
drivers/net/ethernet/intel/ixgbe/ixgbe_main.c +55 -8
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PATCH v6 5/5 ixgbe: add extra stats for ndo_ll_poll
In reply to Eliezer TamirAdd additional statistics to the ixgbe driver for ndo_ll_poll Defined under LL_EXTENDED_STATS
---
drivers/net/ethernet/intel/ixgbe/ixgbe.h | 14 ++++++++ drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c | 40 ++++++++++++++++++++++ drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 6 +++ 3 files changed, 60 insertions(+), 0 deletions(-)
drivers/net/ethernet/intel/ixgbe/ixgbe.h +14 -0
@@ -54,6 +54,9 @@#include <net/ll_poll.h> +#ifdef CONFIG_NET_LL_RX_POLL +#define LL_EXTENDED_STATS +#endif /* common prefix used by pr_<> macros */ #undef pr_fmt#define pr_fmt (fmt) KBUILD_MODNAME ": " fmt
@@ -184,6 +187,11 @@ struct ixgbe_rx_buffer {struct ixgbe_queue_stats {u64 packets;u64 bytes; +#ifdef LL_EXTENDED_STATS +u64 yields; +u64 misses; +u64 cleaned; +#endif /* LL_EXTENDED_STATS */ };struct ixgbe_tx_queue_stats {
@@ -391,6 +399,9 @@ static inline int ixgbe_qv_lock_napi(struct ixgbe_q_vector *q_vector)WARN_ON (q_vector->state &IXGBE_QV_STATE_NAPI ); q_vector->state |=IXGBE_QV_STATE_NAPI_YIELD ; rc = false; +#ifdef LL_EXTENDED_STATS + q_vector->tx.ring->stats.yields++; +#endif }else /* we don't care if someone yielded */ q_vector->state =IXGBE_QV_STATE_NAPI ;
@@ -421,6 +432,9 @@ static inline int ixgbe_qv_lock_poll(struct ixgbe_q_vector *q_vector)if ((q_vector->state &IXGBE_QV_LOCKED )) { q_vector->state |=IXGBE_QV_STATE_POLL_YIELD ; rc = false; +#ifdef LL_EXTENDED_STATS + q_vector->rx.ring->stats.yields++; +#endif }else /* preserve yield marks */ q_vector->state |=IXGBE_QV_STATE_POLL ;
drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c +40 -0
@@ -1054,6 +1054,12 @@ static void ixgbe_get_ethtool_stats(struct net_device *netdev, data[i] =0 ; data[i+1 ] =0 ; i +=2 ; +#ifdef LL_EXTENDED_STATS + data[i] =0 ; + data[i+1 ] =0 ; + data[i+2 ] =0 ; + i +=3 ; +#endif continue ; }
@@ -1063,6 +1069,12 @@ static void ixgbe_get_ethtool_stats(struct net_device *netdev, data[i+1 ] = ring->stats.bytes; }while (u64_stats_fetch_retry_bh (&ring->syncp, start)); i +=2 ; +#ifdef LL_EXTENDED_STATS + data[i] = ring->stats.yields; + data[i+1 ] = ring->stats.misses; + data[i+2 ] = ring->stats.cleaned; + i +=3 ; +#endif }for (j =0 ; j <IXGBE_NUM_RX_QUEUES ; j++) { ring = adapter->rx_ring[j];
@@ -1070,6 +1082,12 @@ static void ixgbe_get_ethtool_stats(struct net_device *netdev, data[i] =0 ; data[i+1 ] =0 ; i +=2 ; +#ifdef LL_EXTENDED_STATS + data[i] =0 ; + data[i+1 ] =0 ; + data[i+2 ] =0 ; + i +=3 ; +#endif continue ; }
@@ -1079,6 +1097,12 @@ static void ixgbe_get_ethtool_stats(struct net_device *netdev, data[i+1 ] = ring->stats.bytes; }while (u64_stats_fetch_retry_bh (&ring->syncp, start)); i +=2 ; +#ifdef LL_EXTENDED_STATS + data[i] = ring->stats.yields; + data[i+1 ] = ring->stats.misses; + data[i+2 ] = ring->stats.cleaned; + i +=3 ; +#endif }for (j =0 ; j <IXGBE_MAX_PACKET_BUFFERS ; j++) {
@@ -1115,12 +1139,28 @@ static void ixgbe_get_strings(struct net_device *netdev, u32 stringset, p +=ETH_GSTRING_LEN ;sprintf (p,"tx_queue_%u_bytes" , i); p +=ETH_GSTRING_LEN ; +#ifdef LL_EXTENDED_STATS +sprintf (p,"tx_q_%u_napi_yield" , i); + p +=ETH_GSTRING_LEN ; +sprintf (p,"tx_q_%u_misses" , i); + p +=ETH_GSTRING_LEN ; +sprintf (p,"tx_q_%u_cleaned" , i); + p +=ETH_GSTRING_LEN ; +#endif /* LL_EXTENDED_STATS */ }for (i =0 ; i <IXGBE_NUM_RX_QUEUES ; i++) {sprintf (p,"rx_queue_%u_packets" , i); p +=ETH_GSTRING_LEN ;sprintf (p,"rx_queue_%u_bytes" , i); p +=ETH_GSTRING_LEN ; +#ifdef LL_EXTENDED_STATS +sprintf (p,"rx_q_%u_ll_poll_yield" , i); + p +=ETH_GSTRING_LEN ; +sprintf (p,"rx_q_%u_misses" , i); + p +=ETH_GSTRING_LEN ; +sprintf (p,"rx_q_%u_cleaned" , i); + p +=ETH_GSTRING_LEN ; +#endif /* LL_EXTENDED_STATS */ }for (i =0 ; i <IXGBE_MAX_PACKET_BUFFERS ; i++) {sprintf (p,"tx_pb_%u_pxon" , i);
drivers/net/ethernet/intel/ixgbe/ixgbe_main.c +6 -0
@@ -2016,6 +2016,12 @@ static int ixgbe_low_latency_recv(struct napi_struct *napi)ixgbe_for_each_ring (ring, q_vector->rx) { found =ixgbe_clean_rx_irq (q_vector, ring,4 ); +#ifdef LL_EXTENDED_STATS +if (found) + ring->stats.cleaned += found; +else + ring->stats.misses++; +#endif if (found)break ; }
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