From: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
To: tglx@linutronix.de, peterz@infradead.org, tj@kernel.org,
oleg@redhat.com, paulmck@linux.vnet.ibm.com,
rusty@rustcorp.com.au, mingo@kernel.org,
akpm@linux-foundation.org, namhyung@kernel.org,
walken@google.com, vincent.guittot@linaro.org,
laijs@cn.fujitsu.com
Cc: linux-arch@vger.kernel.org,
Alexander Duyck <alexander.h.duyck@intel.com>,
nikunj@linux.vnet.ibm.com, zhong@linux.vnet.ibm.com,
linux-pm@vger.kernel.org, fweisbec@gmail.com,
linux-kernel@vger.kernel.org, rostedt@goodmis.org,
xiaoguangrong@linux.vnet.ibm.com, sbw@mit.edu,
Eric Dumazet <edumazet@google.com>,
wangyun@linux.vnet.ibm.com,
"Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>,
netdev@vger.kernel.org, Ben Hutchings <bhutchings@solarflare.com>,
Cong Wang <xiyou.wangcong@gmail.com>,
linuxppc-dev@lists.ozlabs.org,
"David S. Miller" <davem@davemloft.net>
Subject: [PATCH v2 20/45] net: Use get/put_online_cpus_atomic() to prevent CPU offline
Date: Wed, 26 Jun 2013 01:59:02 +0530 [thread overview]
Message-ID: <20130625202901.16593.4774.stgit@srivatsabhat.in.ibm.com> (raw)
In-Reply-To: <20130625202452.16593.22810.stgit@srivatsabhat.in.ibm.com>
Once stop_machine() is gone from the CPU offline path, we won't be able
to depend on disabling preemption to prevent CPUs from going offline
from under us.
Use the get/put_online_cpus_atomic() APIs to prevent CPUs from going
offline, while invoking from atomic context.
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Alexander Duyck <alexander.h.duyck@intel.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Ben Hutchings <bhutchings@solarflare.com>
Cc: netdev@vger.kernel.org
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
---
net/core/dev.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/net/core/dev.c b/net/core/dev.c
index fc1e289..90519e9 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3141,7 +3141,7 @@ int netif_rx(struct sk_buff *skb)
struct rps_dev_flow voidflow, *rflow = &voidflow;
int cpu;
- preempt_disable();
+ get_online_cpus_atomic();
rcu_read_lock();
cpu = get_rps_cpu(skb->dev, skb, &rflow);
@@ -3151,7 +3151,7 @@ int netif_rx(struct sk_buff *skb)
ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
rcu_read_unlock();
- preempt_enable();
+ put_online_cpus_atomic();
} else
#endif
{
@@ -3570,6 +3570,7 @@ int netif_receive_skb(struct sk_buff *skb)
struct rps_dev_flow voidflow, *rflow = &voidflow;
int cpu, ret;
+ get_online_cpus_atomic();
rcu_read_lock();
cpu = get_rps_cpu(skb->dev, skb, &rflow);
@@ -3577,9 +3578,11 @@ int netif_receive_skb(struct sk_buff *skb)
if (cpu >= 0) {
ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
rcu_read_unlock();
+ put_online_cpus_atomic();
return ret;
}
rcu_read_unlock();
+ put_online_cpus_atomic();
}
#endif
return __netif_receive_skb(skb);
@@ -3957,6 +3960,7 @@ static void net_rps_action_and_irq_enable(struct softnet_data *sd)
local_irq_enable();
/* Send pending IPI's to kick RPS processing on remote cpus. */
+ get_online_cpus_atomic();
while (remsd) {
struct softnet_data *next = remsd->rps_ipi_next;
@@ -3965,6 +3969,7 @@ static void net_rps_action_and_irq_enable(struct softnet_data *sd)
&remsd->csd, 0);
remsd = next;
}
+ put_online_cpus_atomic();
} else
#endif
local_irq_enable();
next prev parent reply other threads:[~2013-06-25 20:32 UTC|newest]
Thread overview: 72+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-25 20:25 [PATCH v2 00/45] CPU hotplug: stop_machine()-free CPU hotplug, part 1 Srivatsa S. Bhat
2013-06-25 20:25 ` [PATCH v2 01/45] CPU hotplug: Provide APIs to prevent CPU offline from atomic context Srivatsa S. Bhat
2013-06-25 20:26 ` [PATCH v2 02/45] CPU hotplug: Clarify the usage of different synchronization APIs Srivatsa S. Bhat
2013-06-25 20:26 ` [PATCH v2 03/45] Documentation, CPU hotplug: Recommend usage of get/put_online_cpus_atomic() Srivatsa S. Bhat
2013-06-25 20:26 ` [PATCH v2 04/45] CPU hotplug: Add infrastructure to check lacking hotplug synchronization Srivatsa S. Bhat
2013-06-25 20:26 ` [PATCH v2 05/45] CPU hotplug: Protect set_cpu_online() to avoid false-positives Srivatsa S. Bhat
2013-06-25 20:26 ` [PATCH v2 06/45] CPU hotplug: Sprinkle debugging checks to catch locking bugs Srivatsa S. Bhat
2013-06-25 20:26 ` [PATCH v2 07/45] CPU hotplug: Expose the new debug config option Srivatsa S. Bhat
2013-06-25 20:26 ` [PATCH v2 08/45] CPU hotplug: Convert preprocessor macros to static inline functions Srivatsa S. Bhat
2013-06-25 20:27 ` [PATCH v2 09/45] smp: Use get/put_online_cpus_atomic() to prevent CPU offline Srivatsa S. Bhat
2013-06-25 20:27 ` [PATCH v2 10/45] sched/core: " Srivatsa S. Bhat
2013-06-25 20:27 ` [PATCH v2 11/45] migration: Use raw_spin_lock/unlock since interrupts are already disabled Srivatsa S. Bhat
2013-06-25 20:27 ` [PATCH v2 12/45] sched/fair: Use get/put_online_cpus_atomic() to prevent CPU offline Srivatsa S. Bhat
2013-06-25 20:27 ` [PATCH v2 13/45] timer: " Srivatsa S. Bhat
2013-06-25 20:27 ` [PATCH v2 14/45] sched/rt: " Srivatsa S. Bhat
2013-06-25 20:27 ` [PATCH v2 15/45] rcu: " Srivatsa S. Bhat
2013-06-25 22:00 ` Paul E. McKenney
2013-06-26 14:09 ` Srivatsa S. Bhat
2013-06-26 14:29 ` David Laight
2013-06-26 14:34 ` Paul E. McKenney
2013-06-26 14:51 ` Steven Rostedt
2013-06-26 15:21 ` Tejun Heo
2013-06-26 15:33 ` Steven Rostedt
2013-06-26 17:29 ` Tejun Heo
2013-06-26 18:28 ` Srivatsa S. Bhat
2013-06-26 21:34 ` Tejun Heo
2013-06-27 6:53 ` Srivatsa S. Bhat
2013-06-26 18:22 ` Srivatsa S. Bhat
2013-06-27 8:54 ` David Laight
2013-06-27 10:06 ` Srivatsa S. Bhat
2013-06-26 14:45 ` Paul E. McKenney
2013-06-26 18:18 ` Srivatsa S. Bhat
2013-06-26 14:33 ` Paul E. McKenney
2013-06-25 20:28 ` [PATCH v2 16/45] tick-broadcast: " Srivatsa S. Bhat
2013-06-25 20:28 ` [PATCH v2 17/45] time/clocksource: " Srivatsa S. Bhat
2013-06-25 20:28 ` [PATCH v2 18/45] softirq: " Srivatsa S. Bhat
2013-06-25 20:28 ` [PATCH v2 19/45] irq: " Srivatsa S. Bhat
2013-06-25 20:29 ` Srivatsa S. Bhat [this message]
2013-06-25 20:29 ` [PATCH v2 21/45] block: " Srivatsa S. Bhat
2013-06-25 20:29 ` [PATCH v2 22/45] percpu_counter: " Srivatsa S. Bhat
2013-06-25 20:29 ` [PATCH v2 23/45] infiniband: ehca: " Srivatsa S. Bhat
2013-06-25 20:29 ` [PATCH v2 24/45] [SCSI] fcoe: " Srivatsa S. Bhat
2013-06-25 20:30 ` [PATCH v2 25/45] staging/octeon: " Srivatsa S. Bhat
2013-06-25 20:45 ` Greg Kroah-Hartman
2013-06-25 20:30 ` [PATCH v2 26/45] x86: " Srivatsa S. Bhat
2013-06-25 20:30 ` [PATCH v2 27/45] perf/x86: " Srivatsa S. Bhat
2013-06-25 20:30 ` [PATCH v2 28/45] KVM: " Srivatsa S. Bhat
2013-06-26 8:20 ` Paolo Bonzini
2013-06-25 20:30 ` [PATCH v2 29/45] kvm/vmx: " Srivatsa S. Bhat
2013-06-26 7:46 ` Paolo Bonzini
2013-06-26 8:06 ` Srivatsa S. Bhat
2013-06-26 8:23 ` Paolo Bonzini
2013-06-26 8:41 ` Srivatsa S. Bhat
2013-06-26 8:57 ` Paolo Bonzini
2013-06-25 20:30 ` [PATCH v2 30/45] x86/xen: " Srivatsa S. Bhat
2013-06-25 20:31 ` [PATCH v2 31/45] alpha/smp: " Srivatsa S. Bhat
2013-06-25 20:31 ` [PATCH v2 32/45] blackfin/smp: " Srivatsa S. Bhat
2013-06-25 20:31 ` [PATCH v2 33/45] cris/smp: " Srivatsa S. Bhat
2013-06-25 20:32 ` [PATCH v2 34/45] hexagon/smp: " Srivatsa S. Bhat
2013-06-25 20:32 ` [PATCH v2 35/45] ia64: irq, perfmon: " Srivatsa S. Bhat
2013-06-25 20:32 ` [PATCH v2 36/45] ia64: smp, tlb: " Srivatsa S. Bhat
2013-06-25 20:32 ` [PATCH v2 37/45] m32r: " Srivatsa S. Bhat
2013-06-25 20:32 ` [PATCH v2 38/45] MIPS: " Srivatsa S. Bhat
2013-06-26 13:39 ` Ralf Baechle
2013-06-27 7:08 ` Srivatsa S. Bhat
2013-06-25 20:33 ` [PATCH v2 39/45] mn10300: " Srivatsa S. Bhat
2013-06-25 20:33 ` [PATCH v2 40/45] powerpc, irq: Use GFP_ATOMIC allocations in atomic context Srivatsa S. Bhat
2013-06-25 20:33 ` [PATCH v2 41/45] powerpc: Use get/put_online_cpus_atomic() to prevent CPU offline Srivatsa S. Bhat
2013-06-25 20:33 ` [PATCH v2 42/45] powerpc: Use get/put_online_cpus_atomic() to avoid false-positive warning Srivatsa S. Bhat
2013-06-25 20:33 ` [PATCH v2 43/45] sh: Use get/put_online_cpus_atomic() to prevent CPU offline Srivatsa S. Bhat
2013-06-25 20:33 ` [PATCH v2 44/45] sparc: " Srivatsa S. Bhat
2013-06-25 20:34 ` [PATCH v2 45/45] tile: " Srivatsa S. Bhat
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