search for: stop_cpu

...er dpm_suspend_noirq(). Specifically I have seen a deadlock between the callfunc IPI and the stop machine used by xen''s do_suspend() routine. If one CPU has already called dpm_suspend_noirq() then there is a window where it can be sent a callfunc IPI before all the other CPUs have entered stop_cpu(). If this happens then the first CPU ends up spinning in stop_cpu() waiting for the other to rendezvous in state STOPMACHINE_PREPARE while the other is spinning in csd_lock_wait(). Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: xen...

...;ffffffff810e831c>] ? kfree+0xc6/0xcb [69204.815336] [<ffffffff8100e63d>] ? xen_force_evtchn_callback+0x9/0xa [69204.815336] [<ffffffff8100ecf2>] ? check_events+0x12/0x20 [69204.815336] [<ffffffff811f3980>] ? xen_suspend+0xaf/0xc4 [69204.815336] [<ffffffff8108bd2a>] ? stop_cpu+0x83/0xc6 [69204.815336] [<ffffffff81062887>] ? worker_thread+0x188/0x21d [69204.815336] [<ffffffff8108bca7>] ? stop_cpu+0x0/0xc6 [69204.815336] [<ffffffff81065eb2>] ? autoremove_wake_function+0x0/0x2e [69204.815336] [<ffffffff810626ff>] ? worker_thread+0x0/0x21d [69204....

...ne_timeout = 200; /* msecs, arbitrary */ + static void set_state(enum stopmachine_state newstate) { /* Reset ack counter. */ - atomic_set(&thread_ack, num_threads); + atomic_set(&thread_ack, atomic_read(&num_threads)); smp_wmb(); state = newstate; } @@ -67,6 +70,8 @@ static int stop_cpu(struct stop_machine_data *smdata) enum stopmachine_state curstate = STOPMACHINE_NONE; int uninitialized_var(ret); + cpu_set(smp_processor_id(), prepared_cpus); + /* Simple state machine */ do { /* Chill out and ensure we re-read stopmachine_state. */ @@ -90,6 +95,7 @@ static int stop_c...

...ne_timeout = 200; /* msecs, arbitrary */ + static void set_state(enum stopmachine_state newstate) { /* Reset ack counter. */ - atomic_set(&thread_ack, num_threads); + atomic_set(&thread_ack, atomic_read(&num_threads)); smp_wmb(); state = newstate; } @@ -67,6 +70,8 @@ static int stop_cpu(struct stop_machine_data *smdata) enum stopmachine_state curstate = STOPMACHINE_NONE; int uninitialized_var(ret); + cpu_set(smp_processor_id(), prepared_cpus); + /* Simple state machine */ do { /* Chill out and ensure we re-read stopmachine_state. */ @@ -90,6 +95,7 @@ static int stop_c...

...ault is 0 = "never timeout" */ + static void set_state(enum stopmachine_state newstate) { /* Reset ack counter. */ - atomic_set(&thread_ack, num_threads); + atomic_set(&thread_ack, atomic_read(&num_threads)); smp_wmb(); state = newstate; } @@ -67,6 +70,8 @@ static int stop_cpu(struct stop_machine_data *smdata) enum stopmachine_state curstate = STOPMACHINE_NONE; int uninitialized_var(ret); + cpu_set(smp_processor_id(), prepared_cpus); + /* Simple state machine */ do { /* Chill out and ensure we re-read stopmachine_state. */ @@ -90,6 +95,7 @@ static int stop_c...

...ault is 0 = "never timeout" */ + static void set_state(enum stopmachine_state newstate) { /* Reset ack counter. */ - atomic_set(&thread_ack, num_threads); + atomic_set(&thread_ack, atomic_read(&num_threads)); smp_wmb(); state = newstate; } @@ -67,6 +70,8 @@ static int stop_cpu(struct stop_machine_data *smdata) enum stopmachine_state curstate = STOPMACHINE_NONE; int uninitialized_var(ret); + cpu_set(smp_processor_id(), prepared_cpus); + /* Simple state machine */ do { /* Chill out and ensure we re-read stopmachine_state. */ @@ -90,6 +95,7 @@ static int stop_c...

This patch series implements SMP boot for arch/arm, as far as getting all CPUs up and running the idle loop. Changes from v1: - moved barriers out of loop in udelay() - dropped broken GIC change in favour of explanatory comment - made the increment of ready_cpus atomic (I couldn''t move the increment to before signalling the next CPU because the PT switch has to happen between

First off, Apologies for the massive patch series... This series boots a 32-bit dom0 kernel to a command prompt on an ARMv8 (AArch64) model. The kernel is the same one as I am currently using with the 32 bit hypervisor I haven''t yet tried starting a guest or anything super advanced like that ;-). Also there is not real support for 64-bit domains at all, although in one or two places I

This round implements all of the review comments from V2 and all patches are now acked. Unless there are any objections I intend to apply later this morning. Ian.