From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: David Miller <davem@davemloft.net>,
bpf@vger.kernel.org, netdev@vger.kernel.org,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Sebastian Sewior <bigeasy@linutronix.de>,
Peter Zijlstra <peterz@infradead.org>,
Clark Williams <williams@redhat.com>,
Steven Rostedt <rostedt@goodmis.org>,
Juri Lelli <juri.lelli@redhat.com>,
Ingo Molnar <mingo@kernel.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Vinicius Costa Gomes <vinicius.gomes@intel.com>,
Jakub Kicinski <kuba@kernel.org>
Subject: [patch V3 11/22] bpf: Replace cant_sleep() with cant_migrate()
Date: Mon, 24 Feb 2020 15:01:42 +0100 [thread overview]
Message-ID: <20200224145643.583038889@linutronix.de> (raw)
In-Reply-To: 20200224140131.461979697@linutronix.de
As already discussed in the previous change which introduced
BPF_RUN_PROG_PIN_ON_CPU() BPF only requires to disable migration to
guarantee per CPUness.
If RT substitutes the preempt disable based migration protection then the
cant_sleep() check will obviously trigger as preemption is not disabled.
Replace it by cant_migrate() which maps to cant_sleep() on a non RT kernel
and will verify that migration is disabled on a full RT kernel.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
include/linux/filter.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -561,7 +561,7 @@ DECLARE_STATIC_KEY_FALSE(bpf_stats_enabl
#define __BPF_PROG_RUN(prog, ctx, dfunc) ({ \
u32 ret; \
- cant_sleep(); \
+ cant_migrate(); \
if (static_branch_unlikely(&bpf_stats_enabled_key)) { \
struct bpf_prog_stats *stats; \
u64 start = sched_clock(); \
next prev parent reply other threads:[~2020-02-24 15:03 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-24 14:01 [patch V3 00/22] bpf: Make BPF and PREEMPT_RT co-exist Thomas Gleixner
2020-02-24 14:01 ` [patch V3 01/22] bpf: Tighten the requirements for preallocated hash maps Thomas Gleixner
2020-02-24 14:01 ` [patch V3 02/22] bpf: Enforce preallocation for instrumentation programs on RT Thomas Gleixner
2020-02-24 14:01 ` [patch V3 03/22] bpf: Update locking comment in hashtab code Thomas Gleixner
2020-02-24 14:01 ` [patch V3 04/22] bpf/tracing: Remove redundant preempt_disable() in __bpf_trace_run() Thomas Gleixner
2020-02-24 14:01 ` [patch V3 05/22] bpf/trace: Remove EXPORT from trace_call_bpf() Thomas Gleixner
2020-02-24 18:16 ` Alexei Starovoitov
2020-02-24 14:01 ` [patch V3 06/22] bpf/trace: Remove redundant preempt_disable " Thomas Gleixner
2020-02-24 19:40 ` Alexei Starovoitov
2020-02-24 20:42 ` Thomas Gleixner
2020-02-25 0:33 ` Alexei Starovoitov
2020-02-25 12:36 ` Thomas Gleixner
2020-02-24 14:01 ` [patch V3 07/22] perf/bpf: Remove preempt disable around BPF invocation Thomas Gleixner
2020-02-24 14:01 ` [patch V3 08/22] bpf: Remove recursion prevention from rcu free callback Thomas Gleixner
2020-02-24 14:01 ` [patch V3 09/22] bpf: Dont iterate over possible CPUs with interrupts disabled Thomas Gleixner
2020-02-24 14:01 ` [patch V3 10/22] bpf: Provide bpf_prog_run_pin_on_cpu() helper Thomas Gleixner
2020-02-24 18:14 ` Thomas Gleixner
2020-02-24 18:41 ` [patch V4 " Thomas Gleixner
2020-02-24 14:01 ` Thomas Gleixner [this message]
2020-02-24 14:01 ` [patch V3 12/22] bpf: Use bpf_prog_run_pin_on_cpu() at simple call sites Thomas Gleixner
2020-02-24 14:01 ` [patch V3 13/22] bpf/tests: Use migrate disable instead of preempt disable Thomas Gleixner
2020-02-24 14:01 ` [patch V3 14/22] bpf: Use migrate_disable/enabe() in trampoline code Thomas Gleixner
2020-02-24 14:01 ` [patch V3 15/22] bpf: Use migrate_disable/enable in array macros and cgroup/lirc code Thomas Gleixner
2020-02-24 14:01 ` [patch V3 16/22] bpf: Provide recursion prevention helpers Thomas Gleixner
2020-02-24 14:01 ` [patch V3 17/22] bpf: Use recursion prevention helpers in hashtab code Thomas Gleixner
2020-02-24 14:01 ` [patch V3 18/22] bpf: Replace open coded recursion prevention in sys_bpf() Thomas Gleixner
2020-02-24 14:01 ` [patch V3 19/22] bpf: Factor out hashtab bucket lock operations Thomas Gleixner
2020-02-24 14:01 ` [patch V3 20/22] bpf: Prepare hashtab locking for PREEMPT_RT Thomas Gleixner
2020-02-24 14:01 ` [patch V3 21/22] bpf, lpm: Make locking RT friendly Thomas Gleixner
2020-02-24 14:01 ` [patch V3 22/22] bpf/stackmap: Dont trylock mmap_sem with PREEMPT_RT and interrupts disabled Thomas Gleixner
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