[Intel-wired-lan] [RFC PATCH bpf-next v2 2/9] net: add SO_BUSY_POLL_BUDGET socket option
Björn Töpel
bjorn.topel at gmail.com
Thu Nov 5 10:28:05 UTC 2020
From: Björn Töpel <bjorn.topel at intel.com>
This option lets a user set a per socket NAPI budget for
busy-polling. If the options is not set, it will use the default of 8.
Signed-off-by: Björn Töpel <bjorn.topel at intel.com>
---
arch/alpha/include/uapi/asm/socket.h | 1 +
arch/mips/include/uapi/asm/socket.h | 1 +
arch/parisc/include/uapi/asm/socket.h | 1 +
arch/sparc/include/uapi/asm/socket.h | 1 +
fs/eventpoll.c | 3 ++-
include/net/busy_poll.h | 7 +++++--
include/net/sock.h | 1 +
include/uapi/asm-generic/socket.h | 1 +
net/core/dev.c | 21 ++++++++++-----------
net/core/sock.c | 10 ++++++++++
10 files changed, 33 insertions(+), 14 deletions(-)
diff --git a/arch/alpha/include/uapi/asm/socket.h b/arch/alpha/include/uapi/asm/socket.h
index 538359642554..57420356ce4c 100644
--- a/arch/alpha/include/uapi/asm/socket.h
+++ b/arch/alpha/include/uapi/asm/socket.h
@@ -125,6 +125,7 @@
#define SO_DETACH_REUSEPORT_BPF 68
#define SO_PREFER_BUSY_POLL 69
+#define SO_BUSY_POLL_BUDGET 70
#if !defined(__KERNEL__)
diff --git a/arch/mips/include/uapi/asm/socket.h b/arch/mips/include/uapi/asm/socket.h
index e406e73b5e6e..2d949969313b 100644
--- a/arch/mips/include/uapi/asm/socket.h
+++ b/arch/mips/include/uapi/asm/socket.h
@@ -136,6 +136,7 @@
#define SO_DETACH_REUSEPORT_BPF 68
#define SO_PREFER_BUSY_POLL 69
+#define SO_BUSY_POLL_BUDGET 70
#if !defined(__KERNEL__)
diff --git a/arch/parisc/include/uapi/asm/socket.h b/arch/parisc/include/uapi/asm/socket.h
index 1bc46200889d..f60904329bbc 100644
--- a/arch/parisc/include/uapi/asm/socket.h
+++ b/arch/parisc/include/uapi/asm/socket.h
@@ -117,6 +117,7 @@
#define SO_DETACH_REUSEPORT_BPF 0x4042
#define SO_PREFER_BUSY_POLL 0x4043
+#define SO_BUSY_POLL_BUDGET 0x4044
#if !defined(__KERNEL__)
diff --git a/arch/sparc/include/uapi/asm/socket.h b/arch/sparc/include/uapi/asm/socket.h
index 99688cf673a4..848a22fbac20 100644
--- a/arch/sparc/include/uapi/asm/socket.h
+++ b/arch/sparc/include/uapi/asm/socket.h
@@ -118,6 +118,7 @@
#define SO_DETACH_REUSEPORT_BPF 0x0047
#define SO_PREFER_BUSY_POLL 0x0048
+#define SO_BUSY_POLL_BUDGET 0x0049
#if !defined(__KERNEL__)
diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index e11fab3a0b9e..73c346e503d7 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -397,7 +397,8 @@ static void ep_busy_loop(struct eventpoll *ep, int nonblock)
unsigned int napi_id = READ_ONCE(ep->napi_id);
if ((napi_id >= MIN_NAPI_ID) && net_busy_loop_on())
- napi_busy_loop(napi_id, nonblock ? NULL : ep_busy_loop_end, ep, false);
+ napi_busy_loop(napi_id, nonblock ? NULL : ep_busy_loop_end, ep, false,
+ BUSY_POLL_BUDGET);
}
static inline void ep_reset_busy_poll_napi_id(struct eventpoll *ep)
diff --git a/include/net/busy_poll.h b/include/net/busy_poll.h
index 0292b8353d7e..b4f653cc15a7 100644
--- a/include/net/busy_poll.h
+++ b/include/net/busy_poll.h
@@ -23,6 +23,8 @@
*/
#define MIN_NAPI_ID ((unsigned int)(NR_CPUS + 1))
+#define BUSY_POLL_BUDGET 8
+
#ifdef CONFIG_NET_RX_BUSY_POLL
struct napi_struct;
@@ -43,7 +45,7 @@ bool sk_busy_loop_end(void *p, unsigned long start_time);
void napi_busy_loop(unsigned int napi_id,
bool (*loop_end)(void *, unsigned long),
- void *loop_end_arg, bool prefer_busy_poll);
+ void *loop_end_arg, bool prefer_busy_poll, u16 budget);
#else /* CONFIG_NET_RX_BUSY_POLL */
static inline unsigned long net_busy_loop_on(void)
@@ -106,7 +108,8 @@ static inline void sk_busy_loop(struct sock *sk, int nonblock)
if (napi_id >= MIN_NAPI_ID)
napi_busy_loop(napi_id, nonblock ? NULL : sk_busy_loop_end, sk,
- READ_ONCE(sk->sk_prefer_busy_poll));
+ READ_ONCE(sk->sk_prefer_busy_poll),
+ sk->sk_busy_poll_budget ?: BUSY_POLL_BUDGET);
#endif
}
diff --git a/include/net/sock.h b/include/net/sock.h
index 716960a15e83..1ddfb4a2dac2 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -481,6 +481,7 @@ struct sock {
kuid_t sk_uid;
#ifdef CONFIG_NET_RX_BUSY_POLL
u8 sk_prefer_busy_poll;
+ u16 sk_busy_poll_budget;
#endif
struct pid *sk_peer_pid;
const struct cred *sk_peer_cred;
diff --git a/include/uapi/asm-generic/socket.h b/include/uapi/asm-generic/socket.h
index 7dd02408b7ce..4dcd13d097a9 100644
--- a/include/uapi/asm-generic/socket.h
+++ b/include/uapi/asm-generic/socket.h
@@ -120,6 +120,7 @@
#define SO_DETACH_REUSEPORT_BPF 68
#define SO_PREFER_BUSY_POLL 69
+#define SO_BUSY_POLL_BUDGET 70
#if !defined(__KERNEL__)
diff --git a/net/core/dev.c b/net/core/dev.c
index 49015b059549..33c67004f2ad 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6492,8 +6492,6 @@ static struct napi_struct *napi_by_id(unsigned int napi_id)
#if defined(CONFIG_NET_RX_BUSY_POLL)
-#define BUSY_POLL_BUDGET 8
-
static void __busy_poll_stop(struct napi_struct *napi, bool skip_schedule)
{
if (!skip_schedule) {
@@ -6513,7 +6511,8 @@ static void __busy_poll_stop(struct napi_struct *napi, bool skip_schedule)
clear_bit(NAPI_STATE_SCHED, &napi->state);
}
-static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock, bool prefer_busy_poll)
+static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock, bool prefer_busy_poll,
+ u16 budget)
{
bool skip_schedule = false;
unsigned long timeout;
@@ -6545,21 +6544,21 @@ static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock, bool
/* All we really want here is to re-enable device interrupts.
* Ideally, a new ndo_busy_poll_stop() could avoid another round.
*/
- rc = napi->poll(napi, BUSY_POLL_BUDGET);
+ rc = napi->poll(napi, budget);
/* We can't gro_normal_list() here, because napi->poll() might have
* rearmed the napi (napi_complete_done()) in which case it could
* already be running on another CPU.
*/
- trace_napi_poll(napi, rc, BUSY_POLL_BUDGET);
+ trace_napi_poll(napi, rc, budget);
netpoll_poll_unlock(have_poll_lock);
- if (rc == BUSY_POLL_BUDGET)
+ if (rc == budget)
__busy_poll_stop(napi, skip_schedule);
local_bh_enable();
}
void napi_busy_loop(unsigned int napi_id,
bool (*loop_end)(void *, unsigned long),
- void *loop_end_arg, bool prefer_busy_poll)
+ void *loop_end_arg, bool prefer_busy_poll, u16 budget)
{
unsigned long start_time = loop_end ? busy_loop_current_time() : 0;
int (*napi_poll)(struct napi_struct *napi, int budget);
@@ -6602,8 +6601,8 @@ void napi_busy_loop(unsigned int napi_id,
have_poll_lock = netpoll_poll_lock(napi);
napi_poll = napi->poll;
}
- work = napi_poll(napi, BUSY_POLL_BUDGET);
- trace_napi_poll(napi, work, BUSY_POLL_BUDGET);
+ work = napi_poll(napi, budget);
+ trace_napi_poll(napi, work, budget);
gro_normal_list(napi);
count:
if (work > 0)
@@ -6616,7 +6615,7 @@ void napi_busy_loop(unsigned int napi_id,
if (unlikely(need_resched())) {
if (napi_poll)
- busy_poll_stop(napi, have_poll_lock, prefer_busy_poll);
+ busy_poll_stop(napi, have_poll_lock, prefer_busy_poll, budget);
preempt_enable();
rcu_read_unlock();
cond_resched();
@@ -6627,7 +6626,7 @@ void napi_busy_loop(unsigned int napi_id,
cpu_relax();
}
if (napi_poll)
- busy_poll_stop(napi, have_poll_lock, prefer_busy_poll);
+ busy_poll_stop(napi, have_poll_lock, prefer_busy_poll, budget);
preempt_enable();
out:
rcu_read_unlock();
diff --git a/net/core/sock.c b/net/core/sock.c
index 248f6a763661..e08d5a6ae9d4 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1165,6 +1165,16 @@ int sock_setsockopt(struct socket *sock, int level, int optname,
else
sk->sk_prefer_busy_poll = valbool;
break;
+ case SO_BUSY_POLL_BUDGET:
+ if (val > sk->sk_busy_poll_budget && !capable(CAP_NET_ADMIN)) {
+ ret = -EPERM;
+ } else {
+ if (val < 0)
+ ret = -EINVAL;
+ else
+ sk->sk_busy_poll_budget = val;
+ }
+ break;
#endif
case SO_MAX_PACING_RATE:
--
2.27.0
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