From: Frank Rowand Reverse preempt-rt-allow-immediate-magic-sysrq-output-for-preempt_rt_full.patch The problem addressed by that patch does not exist after applying console-make-rt-friendly-update.patch Signed-off-by: Frank Rowand Link: http://lkml.kernel.org/r/4FB44EF1.9050809@am.sony.com Signed-off-by: Steven Rostedt --- drivers/tty/serial/cpm_uart/cpm_uart_core.c | 2 +- drivers/tty/sysrq.c | 23 ----------------------- include/linux/sysrq.h | 5 ----- kernel/printk.c | 5 ++--- lib/Kconfig.debug | 22 ---------------------- 5 files changed, 3 insertions(+), 54 deletions(-) diff --git a/drivers/tty/serial/cpm_uart/cpm_uart_core.c b/drivers/tty/serial/cpm_uart/cpm_uart_core.c index a8b0559..b418947 100644 --- a/drivers/tty/serial/cpm_uart/cpm_uart_core.c +++ b/drivers/tty/serial/cpm_uart/cpm_uart_core.c @@ -1226,7 +1226,7 @@ static void cpm_uart_console_write(struct console *co, const char *s, { struct uart_cpm_port *pinfo = &cpm_uart_ports[co->index]; unsigned long flags; - int nolock = oops_in_progress || sysrq_in_progress; + int nolock = oops_in_progress; if (unlikely(nolock)) { local_irq_save(flags); diff --git a/drivers/tty/sysrq.c b/drivers/tty/sysrq.c index 5219738..43db715 100644 --- a/drivers/tty/sysrq.c +++ b/drivers/tty/sysrq.c @@ -492,23 +492,6 @@ static void __sysrq_put_key_op(int key, struct sysrq_key_op *op_p) sysrq_key_table[i] = op_p; } -#ifdef CONFIG_MAGIC_SYSRQ_FORCE_PRINTK - -int sysrq_in_progress; - -static void set_sysrq_in_progress(int value) -{ - sysrq_in_progress = value; -} - -#else - -static void set_sysrq_in_progress(int value) -{ -} - -#endif - void __handle_sysrq(int key, bool check_mask) { struct sysrq_key_op *op_p; @@ -517,9 +500,6 @@ void __handle_sysrq(int key, bool check_mask) unsigned long flags; spin_lock_irqsave(&sysrq_key_table_lock, flags); - - set_sysrq_in_progress(1); - /* * Raise the apparent loglevel to maximum so that the sysrq header * is shown to provide the user with positive feedback. We do not @@ -561,9 +541,6 @@ void __handle_sysrq(int key, bool check_mask) printk("\n"); console_loglevel = orig_log_level; } - - set_sysrq_in_progress(0); - spin_unlock_irqrestore(&sysrq_key_table_lock, flags); } diff --git a/include/linux/sysrq.h b/include/linux/sysrq.h index d224c0b..7faf933 100644 --- a/include/linux/sysrq.h +++ b/include/linux/sysrq.h @@ -38,11 +38,6 @@ struct sysrq_key_op { int enable_mask; }; -#ifdef CONFIG_MAGIC_SYSRQ_FORCE_PRINTK -extern int sysrq_in_progress; -#else -#define sysrq_in_progress 0 -#endif #ifdef CONFIG_MAGIC_SYSRQ /* Generic SysRq interface -- you may call it from any device driver, supplying diff --git a/kernel/printk.c b/kernel/printk.c index 66e83e5..85d8795 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -21,7 +21,6 @@ #include #include #include -#include #include #include #include @@ -835,8 +834,8 @@ static int console_trylock_for_printk(unsigned int cpu, unsigned long flags) { int retval = 0, wake = 0; #ifdef CONFIG_PREEMPT_RT_FULL - int lock = (!early_boot_irqs_disabled && !irqs_disabled_flags(flags) && - (preempt_count() <= 1)) || sysrq_in_progress; + int lock = !early_boot_irqs_disabled && !irqs_disabled_flags(flags) && + (preempt_count() <= 1); #else int lock = 1; #endif diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 13a937b..c347db3 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -62,28 +62,6 @@ config MAGIC_SYSRQ keys are documented in . Don't say Y unless you really know what this hack does. -config MAGIC_SYSRQ_FORCE_PRINTK - bool "Force printk from Magic SysRq" - depends on MAGIC_SYSRQ && PREEMPT_RT_FULL - default n - help - Allow the output from Magic SysRq to be output immediately, even if - this causes large latencies. This can cause performance problems - for real-time processes. - - If PREEMPT_RT_FULL, printk() will not try to acquire the console lock - when interrupts or preemption are disabled. If the console lock is - not acquired the printk() output will be buffered, but will not be - output immediately. Some drivers call into the Magic SysRq code - with interrupts or preemption disabled, so the output of Magic SysRq - will be buffered instead of printing immediately if this option is - not selected. - - Even with this option selected, Magic SysRq output will be delayed - if the attempt to acquire the console lock fails. - - Don't say Y unless you really know what this hack does. - config STRIP_ASM_SYMS bool "Strip assembler-generated symbols during link" default n -- 1.7.10.4 -- 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/