![]() | |||||||||||||
Messages in this thread
Patch in this message |
* Daniel Walker <dwalker@mvista.com> wrote: > I found this latency ~5 minutes after boot up, no load . It looks like > vgacon_scroll() has a memset like operation which can grow. do you have PRINTK_IGNORE_LOGLEVEL enabled? If yes then much of the printk code will run with interrupts disabled - hence non-preemptable. PRINTK_IGNORE_LOGLEVEL is a debugging feature for developers. I have added an extra explanation to the Kconfig, see below. Ingo Index: linux/lib/Kconfig.debug =================================================================== --- linux.orig/lib/Kconfig.debug +++ linux/lib/Kconfig.debug @@ -18,6 +18,11 @@ config PRINTK_IGNORE_LOGLEVEL distributions disable kernel log messages during certain phases of system startup.) + NOTE: this option also makes printk non-preemptible, + which might improve the output of debugging info or + crash info, but it might also cause latencies if your + kernel is printk-ing alot. + Normally you dont need or want this option. config DEBUG_KERNEL - 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/ | ||||||||||||
| Last update: 2005-10-18 08:45 [from the cache] ©2003-2008 | |||||||||||||