linux-kernel - [PATCH] printk: Print cpuid along with the timestamp with CONFIG_PRINTK

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20080918193720.GA21915@localdomain>
Date:	Thu, 18 Sep 2008 12:37:20 -0700
From:	Ravikiran G Thirumalai <kiran@...lex86.org>
To:	Andrew Morton <akpm@...ux-foundation.org>
Cc:	linux-kernel@...r.kernel.org
Subject: [PATCH] printk: Print cpuid along with the timestamp with
	CONFIG_PRINTK_TIME

I found it useful to have the cpuid of the printing cpu along with the
timestamp -- especially while debugging hangs during bootups.

I don't know why this hasn't been implemened in the kernel yet, and
cannot think of a strong reason not to have it.  Yes, the cpuid prefix will
take 5 more characters per line,  but having  the cpuid info is worth it,
I think.

Thanks,
Kiran

---


Add cpuid information to printk if CONFIG_PRINTK_TIME is enabled.
This information is useful to debug hangs and bootup 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);
--
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/