From: Christian Borntraeger Under load the following bug message appeared while using sysrq-t: BUG: scheduling while atomic: bash/3662/0x00000004 0000000000105b74 000000003ba17740 0000000000000002 0000000000000000 000000003ba177e0 000000003ba17758 000000003ba17758 0000000000105bfe 0000000000817ba8 000000003f2a5350 0000000000000000 0000000000000000 000000003ba17740 000000000000000c 000000003ba17740 000000003ba177b0 0000000000568630 0000000000105bfe 000000003ba17740 000000003ba17790 Call Trace: ([<0000000000105b74>] show_trace+0x13c/0x158) [<0000000000105c58>] show_stack+0xc8/0xfc [<0000000000105cbc>] dump_stack+0x30/0x40 [<000000000012a0c8>] __schedule_bug+0x84/0x94 [<000000000056234e>] schedule+0x5ea/0x970 [<0000000000477cd2>] __sclp_vt220_write+0x1f6/0x3ec [<0000000000477f00>] sclp_vt220_con_write+0x38/0x48 [<0000000000130b4a>] __call_console_drivers+0xbe/0xd8 [<0000000000130bf0>] _call_console_drivers+0x8c/0xd0 [<0000000000130eea>] release_console_sem+0x1a6/0x2fc [<0000000000131786>] vprintk+0x262/0x480 [<00000000001319fa>] printk+0x56/0x68 [<0000000000125aaa>] print_cfs_rq+0x45e/0x4a4 [<000000000012614e>] sched_debug_show+0x65e/0xee8 [<000000000012a8fc>] show_state_filter+0x1cc/0x1f0 [<000000000044d39c>] sysrq_handle_showstate+0x2c/0x3c [<000000000044d1fe>] __handle_sysrq+0xae/0x18c [<00000000002001f2>] write_sysrq_trigger+0x8a/0x90 [<00000000001f7862>] proc_reg_write+0x9a/0xc4 [<00000000001a83d4>] vfs_write+0xb8/0x174 [<00000000001a8b88>] sys_write+0x58/0x8c [<0000000000112e7c>] sysc_noemu+0x10/0x16 [<0000020000116f68>] 0x20000116f68 The problem seems to be, that with a full console buffer, release_console_sem disables interrupts with spin_lock_irqsave and then calls the console function without enabling interrupts. __sclp_vt220_write checks for in_interrupt, to decide if it can schedule. It should check for in_atomic instead. The same is true for sclp_tty.c. Signed-off-by: Christian Borntraeger Signed-off-by: Martin Schwidefsky --- drivers/s390/char/sclp_tty.c | 2 +- drivers/s390/char/sclp_vt220.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) Index: quilt-2.6/drivers/s390/char/sclp_tty.c =================================================================== --- quilt-2.6.orig/drivers/s390/char/sclp_tty.c +++ quilt-2.6/drivers/s390/char/sclp_tty.c @@ -332,7 +332,7 @@ sclp_tty_write_string(const unsigned cha if (sclp_ttybuf == NULL) { while (list_empty(&sclp_tty_pages)) { spin_unlock_irqrestore(&sclp_tty_lock, flags); - if (in_interrupt()) + if (in_atomic()) sclp_sync_wait(); else wait_event(sclp_tty_waitq, Index: quilt-2.6/drivers/s390/char/sclp_vt220.c =================================================================== --- quilt-2.6.orig/drivers/s390/char/sclp_vt220.c +++ quilt-2.6/drivers/s390/char/sclp_vt220.c @@ -400,7 +400,7 @@ __sclp_vt220_write(const unsigned char * while (list_empty(&sclp_vt220_empty)) { spin_unlock_irqrestore(&sclp_vt220_lock, flags); - if (in_interrupt()) + if (in_atomic()) sclp_sync_wait(); else wait_event(sclp_vt220_waitq, -- blue skies, Martin. "Reality continues to ruin my life." - Calvin. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/