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author | Keir Fraser <keir.fraser@citrix.com> | 2010-05-06 11:59:55 +0100 |
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committer | Keir Fraser <keir.fraser@citrix.com> | 2010-05-06 11:59:55 +0100 |
commit | 81e0a49aeb24a77875dac3ecf6be7b998c6cf0f8 (patch) | |
tree | 2b17e106a1152a07a4911f5ac61eb15c31841256 /xen/common/keyhandler.c | |
parent | c931e4face0ab47ea749e3e32e7734e90c57d6ba (diff) | |
download | xen-81e0a49aeb24a77875dac3ecf6be7b998c6cf0f8.tar.gz xen-81e0a49aeb24a77875dac3ecf6be7b998c6cf0f8.tar.bz2 xen-81e0a49aeb24a77875dac3ecf6be7b998c6cf0f8.zip |
Reduce '0' debug key's global impact
On large systems, dumping state may cause time management to get
stalled for so long a period that it wouldn't recover. Therefore add
a tasklet-based alternative mechanism to handle Dom0 state dumps.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Diffstat (limited to 'xen/common/keyhandler.c')
-rw-r--r-- | xen/common/keyhandler.c | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/xen/common/keyhandler.c b/xen/common/keyhandler.c index 611724a645..88ddd88f28 100644 --- a/xen/common/keyhandler.c +++ b/xen/common/keyhandler.c @@ -19,6 +19,7 @@ static struct keyhandler *key_table[256]; static unsigned char keypress_key; +static bool_t alt_key_handling; char keyhandler_scratch[1024]; @@ -115,6 +116,26 @@ static struct keyhandler dump_registers_keyhandler = { .desc = "dump registers" }; +static DECLARE_TASKLET(dump_dom0_tasklet, NULL, 0); + +static void dump_dom0_action(unsigned long arg) +{ + struct vcpu *v = (void *)arg; + + for ( ; ; ) + { + vcpu_show_execution_state(v); + if ( (v = v->next_in_list) == NULL ) + break; + if ( softirq_pending(smp_processor_id()) ) + { + dump_dom0_tasklet.data = (unsigned long)v; + tasklet_schedule_on_cpu(&dump_dom0_tasklet, v->processor); + break; + } + } +} + static void dump_dom0_registers(unsigned char key) { struct vcpu *v; @@ -125,7 +146,17 @@ static void dump_dom0_registers(unsigned char key) printk("'%c' pressed -> dumping Dom0's registers\n", key); for_each_vcpu ( dom0, v ) + { + if ( alt_key_handling && softirq_pending(smp_processor_id()) ) + { + tasklet_kill(&dump_dom0_tasklet); + tasklet_init(&dump_dom0_tasklet, dump_dom0_action, + (unsigned long)v); + tasklet_schedule_on_cpu(&dump_dom0_tasklet, v->processor); + return; + } vcpu_show_execution_state(v); + } } static struct keyhandler dump_dom0_registers_keyhandler = { @@ -425,8 +456,28 @@ static struct keyhandler do_debug_key_keyhandler = { .desc = "trap to xendbg" }; +static void do_toggle_alt_key(unsigned char key, struct cpu_user_regs *regs) +{ + alt_key_handling = !alt_key_handling; + printk("'%c' pressed -> using %s key handling\n", key, + alt_key_handling ? "alternative" : "normal"); +} + +static struct keyhandler toggle_alt_keyhandler = { + .irq_callback = 1, + .u.irq_fn = do_toggle_alt_key, + .desc = "toggle alternative key handling" +}; + void __init initialize_keytable(void) { + if ( num_present_cpus() > 16 ) + { + alt_key_handling = 1; + printk(XENLOG_INFO "Defaulting to alternative key handling; " + "send 'A' to switch to normal mode.\n"); + } + register_keyhandler('A', &toggle_alt_keyhandler); register_keyhandler('d', &dump_registers_keyhandler); register_keyhandler('h', &show_handlers_keyhandler); register_keyhandler('q', &dump_domains_keyhandler); |