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Message-ID: <20080919003509.GB21915@localdomain> Date: Thu, 18 Sep 2008 17:35:09 -0700 From: Ravikiran G Thirumalai <kiran@...lex86.org> To: Andrew Morton <akpm@...ux-foundation.org> Cc: linux-kernel@...r.kernel.org Subject: Re: [PATCH] printk: Print cpuid along with the timestamp with CONFIG_PRINTK_TIME On Thu, Sep 18, 2008 at 12:51:23PM -0700, Andrew Morton wrote: >On Thu, 18 Sep 2008 12:37:20 -0700 >Ravikiran G Thirumalai <kiran@...lex86.org> wrote: >> >> Signed-off-by: Ravikiran Thirumalai <kiran@...lex86.org> >> >> Index: linux-git/kernel/printk.c >> =================================================================== >> --- linux-git.orig/kernel/printk.c 2008-09-16 15:37:48.000000000 -0700 >> +++ linux-git/kernel/printk.c 2008-09-18 12:27:10.489662938 -0700 >> @@ -739,9 +739,10 @@ asmlinkage int vprintk(const char *fmt, >> >> t = cpu_clock(printk_cpu); >> nanosec_rem = do_div(t, 1000000000); >> - tlen = sprintf(tbuf, "[%5lu.%06lu] ", >> + tlen = sprintf(tbuf, "[%5lu.%06lu:%d] ", >> (unsigned long) t, >> - nanosec_rem / 1000); >> + nanosec_rem / 1000, >> + printk_cpu); >> >> for (tp = tbuf; tp < tbuf + tlen; tp++) >> emit_log_char(*tp); > > >Your patch illogically ties the cpu-id-printing feature to the >printk.time feature. I guess that's liveable with, but >Documentation/kernel-parameters.txt should be updated. > Didn't realize Documentation/kernel-parameters.txt had reference and even a runtime parameter to control this! I always enabled CONFIG_PRINTK_TIME to get timestamps. Here's an updated patch. As for the cpuid with the timestamp, the timestamp that is being is the printed the cpu's time stamp. --- Add cpuid information to printk if CONFIG_PRINTK_TIME is enabled. This information is useful to debug hangs and boot issues. Signed-off-by: Ravikiran Thirumalai <kiran@...lex86.org> Index: linux-git/kernel/printk.c =================================================================== --- linux-git.orig/kernel/printk.c 2008-09-16 15:37:48.000000000 -0700 +++ linux-git/kernel/printk.c 2008-09-18 12:27:10.489662938 -0700 @@ -739,9 +739,10 @@ asmlinkage int vprintk(const char *fmt, t = cpu_clock(printk_cpu); nanosec_rem = do_div(t, 1000000000); - tlen = sprintf(tbuf, "[%5lu.%06lu] ", + tlen = sprintf(tbuf, "[%5lu.%06lu:%d] ", (unsigned long) t, - nanosec_rem / 1000); + nanosec_rem / 1000, + printk_cpu); for (tp = tbuf; tp < tbuf + tlen; tp++) emit_log_char(*tp); Index: linux-git/Documentation/kernel-parameters.txt =================================================================== --- linux-git.orig/Documentation/kernel-parameters.txt 2008-09-16 11:30:13.000000000 -0700 +++ linux-git/Documentation/kernel-parameters.txt 2008-09-18 17:11:35.167079714 -0700 @@ -1687,7 +1687,10 @@ and is between 256 and 4096 characters. default: off. printk.time= Show timing data prefixed to each printk message line - Format: <bool> (1/Y/y=enable, 0/N/n=disable) + Format: <bool> (1/Y/y=enable, 0/N/n=disable). + Per-cpu timestamps are prefixed as + "[sssss.uuuuuu:cpuid]" on each and every line printed, + if this option is enabled. profile= [KNL] Enable kernel profiling via /proc/profile Format: [schedule,]<number> -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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