From 372579427a5040a26dfee78464b50e2bdf27ef26 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Alex=20Benn=C3=A9e?= Date: Thu, 23 Feb 2017 18:29:14 +0000 Subject: tcg: enable thread-per-vCPU MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit There are a couple of changes that occur at the same time here: - introduce a single vCPU qemu_tcg_cpu_thread_fn One of these is spawned per vCPU with its own Thread and Condition variables. qemu_tcg_rr_cpu_thread_fn is the new name for the old single threaded function. - the TLS current_cpu variable is now live for the lifetime of MTTCG vCPU threads. This is for future work where async jobs need to know the vCPU context they are operating in. The user to switch on multi-thread behaviour and spawn a thread per-vCPU. For a simple test kvm-unit-test like: ./arm/run ./arm/locking-test.flat -smp 4 -accel tcg,thread=multi Will now use 4 vCPU threads and have an expected FAIL (instead of the unexpected PASS) as the default mode of the test has no protection when incrementing a shared variable. We enable the parallel_cpus flag to ensure we generate correct barrier and atomic code if supported by the front and backends. This doesn't automatically enable MTTCG until default_mttcg_enabled() is updated to check the configuration is supported. Signed-off-by: KONRAD Frederic Signed-off-by: Paolo Bonzini [AJB: Some fixes, conditionally, commit rewording] Signed-off-by: Alex Bennée Reviewed-by: Richard Henderson --- cpu-exec.c | 4 ---- 1 file changed, 4 deletions(-) (limited to 'cpu-exec.c') diff --git a/cpu-exec.c b/cpu-exec.c index 85f14d4..2edd26e 100644 --- a/cpu-exec.c +++ b/cpu-exec.c @@ -396,7 +396,6 @@ static inline bool cpu_handle_halt(CPUState *cpu) } #endif if (!cpu_has_work(cpu)) { - current_cpu = NULL; return true; } @@ -675,8 +674,5 @@ int cpu_exec(CPUState *cpu) cc->cpu_exec_exit(cpu); rcu_read_unlock(); - /* fail safe : never use current_cpu outside cpu_exec() */ - current_cpu = NULL; - return ret; } -- cgit v1.1