/* * net busy poll support * Copyright(c) 2013 Intel Corporation. * * This program is free software; you can redistribute it and/or modify it * under the terms and conditions of the GNU General Public License, * version 2, as published by the Free Software Foundation. * * This program is distributed in the hope it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for * more details. * * You should have received a copy of the GNU General Public License along with * this program; if not, write to the Free Software Foundation, Inc., * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. * * Author: Eliezer Tamir * * Contact Information: * e1000-devel Mailing List */ #ifndef _LINUX_NET_BUSY_POLL_H #define _LINUX_NET_BUSY_POLL_H #include #include #ifdef CONFIG_NET_RX_BUSY_POLL struct napi_struct; extern unsigned int sysctl_net_busy_read __read_mostly; extern unsigned int sysctl_net_busy_poll __read_mostly; /* return values from ndo_ll_poll */ #define LL_FLUSH_FAILED -1 #define LL_FLUSH_BUSY -2 static inline bool net_busy_loop_on(void) { return sysctl_net_busy_poll; } static inline u64 busy_loop_us_clock(void) { return local_clock() >> 10; } static inline unsigned long sk_busy_loop_end_time(struct sock *sk) { return busy_loop_us_clock() + ACCESS_ONCE(sk->sk_ll_usec); } /* in poll/select we use the global sysctl_net_ll_poll value */ static inline unsigned long busy_loop_end_time(void) { return busy_loop_us_clock() + ACCESS_ONCE(sysctl_net_busy_poll); } static inline bool sk_can_busy_loop(const struct sock *sk) { return sk->sk_ll_usec && sk->sk_napi_id && !signal_pending(current); } static inline bool busy_loop_timeout(unsigned long end_time) { unsigned long now = busy_loop_us_clock(); return time_after(now, end_time); } bool sk_busy_loop(struct sock *sk, int nonblock); /* used in the NIC receive handler to mark the skb */ static inline void skb_mark_napi_id(struct sk_buff *skb, struct napi_struct *napi) { skb->napi_id = napi->napi_id; } #else /* CONFIG_NET_RX_BUSY_POLL */ static inline unsigned long net_busy_loop_on(void) { return 0; } static inline unsigned long busy_loop_end_time(void) { return 0; } static inline bool sk_can_busy_loop(struct sock *sk) { return false; } static inline void skb_mark_napi_id(struct sk_buff *skb, struct napi_struct *napi) { } static inline bool busy_loop_timeout(unsigned long end_time) { return true; } static inline bool sk_busy_loop(struct sock *sk, int nonblock) { return false; } #endif /* CONFIG_NET_RX_BUSY_POLL */ /* used in the protocol hanlder to propagate the napi_id to the socket */ static inline void sk_mark_napi_id(struct sock *sk, const struct sk_buff *skb) { #ifdef CONFIG_NET_RX_BUSY_POLL sk->sk_napi_id = skb->napi_id; #endif } /* variant used for unconnected sockets */ static inline void sk_mark_napi_id_once(struct sock *sk, const struct sk_buff *skb) { #ifdef CONFIG_NET_RX_BUSY_POLL if (!sk->sk_napi_id) sk->sk_napi_id = skb->napi_id; #endif } #endif /* _LINUX_NET_BUSY_POLL_H */ option value='3' selected='selected'>3space:mode:
authorThomas Gleixner <tglx@linutronix.de>2017-01-31 09:37:34 +0100
committerThomas Gleixner <tglx@linutronix.de>2017-01-31 21:47:58 +0100
commit0becc0ae5b42828785b589f686725ff5bc3b9b25 (patch)
treebe6d0e1f37c38ed0a7dd5da2d4b1e93f0fb43101 /net/ax25
parent24c2503255d35c269b67162c397a1a1c1e02f6ce (diff)
x86/mce: Make timer handling more robust
Erik reported that on a preproduction hardware a CMCI storm triggers the BUG_ON in add_timer_on(). The reason is that the per CPU MCE timer is started by the CMCI logic before the MCE CPU hotplug callback starts the timer with add_timer_on(). So the timer is already queued which triggers the BUG. Using add_timer_on() is pretty pointless in this code because the timer is strictlty per CPU, initialized as pinned and all operations which arm the timer happen on the CPU to which the timer belongs. Simplify the whole machinery by using mod_timer() instead of add_timer_on() which avoids the problem because mod_timer() can handle already queued timers. Use __start_timer() everywhere so the earliest armed expiry time is preserved. Reported-by: Erik Veijola <erik.veijola@intel.com> Tested-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Tony Luck <tony.luck@intel.com> Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1701310936080.3457@nanos Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'net/ax25')