Messages in this thread Patch in this message |  | | | From | Richard Weinberger <> | | Subject | [PATCH -rt] printk: Disable migration instead of preemption | | Date | Mon, 12 Dec 2011 14:35:56 +0100 |
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There is no need do disable preemption in vprintk(), disable_migrate() is sufficient. This fixes also a the following bug in -rt:
[ 14.759233] BUG: sleeping function called from invalid context at /home/rw/linux-rt/kernel/rtmutex.c:645 [ 14.759235] in_atomic(): 1, irqs_disabled(): 0, pid: 547, name: bash [ 14.759244] Pid: 547, comm: bash Not tainted 3.0.12-rt29+ #3 [ 14.759246] Call Trace: [ 14.759301] [<ffffffff8106fade>] __might_sleep+0xeb/0xf0 [ 14.759318] [<ffffffff810ad784>] rt_spin_lock_fastlock.constprop.9+0x21/0x43 [ 14.759336] [<ffffffff8161fef0>] rt_spin_lock+0xe/0x10 [ 14.759354] [<ffffffff81347ad1>] serial8250_console_write+0x81/0x121 [ 14.759366] [<ffffffff8107ecd3>] __call_console_drivers+0x7c/0x93 [ 14.759369] [<ffffffff8107ef31>] _call_console_drivers+0x5c/0x60 [ 14.759372] [<ffffffff8107f7e5>] console_unlock+0x147/0x1a2 [ 14.759374] [<ffffffff8107fd33>] vprintk+0x3ea/0x462 [ 14.759383] [<ffffffff816160e0>] printk+0x51/0x53 [ 14.759399] [<ffffffff811974e4>] ? proc_reg_poll+0x9a/0x9a [ 14.759403] [<ffffffff81335b42>] __handle_sysrq+0x50/0x14d [ 14.759406] [<ffffffff81335c8a>] write_sysrq_trigger+0x4b/0x53 [ 14.759408] [<ffffffff81335c3f>] ? __handle_sysrq+0x14d/0x14d [ 14.759410] [<ffffffff81197583>] proc_reg_write+0x9f/0xbe [ 14.759426] [<ffffffff811497ec>] vfs_write+0xac/0xf3 [ 14.759429] [<ffffffff8114a9b3>] ? fget_light+0x3a/0x9b [ 14.759431] [<ffffffff811499db>] sys_write+0x4a/0x6e [ 14.759438] [<ffffffff81625d52>] system_call_fastpath+0x16/0x1b Signed-off-by: Richard Weinberger <rw@linutronix.de> --- kernel/printk.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/printk.c b/kernel/printk.c index a50af4e..13d0825 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -898,7 +898,7 @@ asmlinkage int vprintk(const char *fmt, va_list args) boot_delay_msec(); printk_delay(); - preempt_disable(); + migrate_disable(); /* This stops the holder of console_sem just where we want him */ raw_local_irq_save(flags); this_cpu = smp_processor_id(); @@ -1029,7 +1029,7 @@ asmlinkage int vprintk(const char *fmt, va_list args) out_restore_irqs: raw_local_irq_restore(flags); - preempt_enable(); + migrate_enable(); return printed_len; } EXPORT_SYMBOL(printk); -- 1.7.7
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