Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753134AbaLTWwU (ORCPT ); Sat, 20 Dec 2014 17:52:20 -0500 Received: from ec2-54-201-57-178.us-west-2.compute.amazonaws.com ([54.201.57.178]:41355 "EHLO ip-172-31-12-36.us-west-2.compute.internal" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752898AbaLTWwT (ORCPT ); Sat, 20 Dec 2014 17:52:19 -0500 Date: Sat, 20 Dec 2014 22:49:08 +0000 From: dwalker@fifo99.com To: Andrew Morton Cc: linux-kernel@vger.kernel.org Subject: [PATCH] printk: add per console loglevel Message-ID: <20141220224908.GB4466@fifo99.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This adds to to the console= command line options allowing the addition of a per console log level setting. examples, console=ttyS0,ll4 console=tty0,ll6 This can be used on systems which have multiple serial consoles, but it's desired for logging to be light on one and heavy on another. Signed-off-by: Daniel Walker --- Documentation/kernel-parameters.txt | 24 ++++++++++++++++++------ include/linux/console.h | 1 + kernel/printk/console_cmdline.h | 9 +++++---- kernel/printk/printk.c | 37 ++++++++++++++++++++++++++++++++++++- 4 files changed, 60 insertions(+), 11 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 4df73da..7e65d5b 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -696,30 +696,42 @@ bytes respectively. Such letter suffixes can also be entirely omitted. console= [KNL] Output console device and options. - tty Use the virtual console device . + tty[,llX] Use the virtual console device . - ttyS[,options] - ttyUSB0[,options] + ttyS[,options][,llX] + ttyUSB0[,options][,llX] Use the specified serial port. The options are of the form "bbbbpnf", where "bbbb" is the baud rate, "p" is parity ("n", "o", or "e"), "n" is number of bits, and "f" is flow control ("r" for RTS or omit it). Default is "9600n8". + "llX" explained below, + See Documentation/serial-console.txt for more information. See Documentation/networking/netconsole.txt for an alternative. - uart[8250],io,[,options] - uart[8250],mmio,[,options] + uart[8250],io,[,options][,llX] + uart[8250],mmio,[,options][,llX] Start an early, polled-mode console on the 8250/16550 UART at the specified I/O port or MMIO address, switching to the matching ttyS device later. The options are the same as for ttyS, above. - hvc Use the hypervisor console device . This is for + + "llX" explained below, + + hvc[,llX] + Use the hypervisor console device . This is for both Xen and PowerPC hypervisors. + "llX" is used to define the loglevel per console. The "X" + defines the loglevel number for this console. The usage + is similar to the "loglevel=" option, and the effect is + the same only per console. The "loglevel=" option takes + precedence of this option. + If the device connected to the port is not a TTY but a braille device, prepend "brl," before the device type, for instance console=brl,ttyS0 diff --git a/include/linux/console.h b/include/linux/console.h index 7571a16..99020d5 100644 --- a/include/linux/console.h +++ b/include/linux/console.h @@ -118,6 +118,7 @@ static inline int con_debug_leave(void) struct console { char name[16]; + int loglevel; void (*write)(struct console *, const char *, unsigned); int (*read)(struct console *, char *, unsigned); struct tty_driver *(*device)(struct console *, int *); diff --git a/kernel/printk/console_cmdline.h b/kernel/printk/console_cmdline.h index cbd69d8..6f6f98f 100644 --- a/kernel/printk/console_cmdline.h +++ b/kernel/printk/console_cmdline.h @@ -3,11 +3,12 @@ struct console_cmdline { - char name[8]; /* Name of the driver */ - int index; /* Minor dev. to use */ - char *options; /* Options for the driver */ + char name[8]; /* Name of the driver */ + int index; /* Minor dev. to use */ + int loglevel; /* Log level for this console */ + char *options; /* Options for the driver */ #ifdef CONFIG_A11Y_BRAILLE_CONSOLE - char *brl_options; /* Options for braille driver */ + char *brl_options; /* Options for braille driver */ #endif }; diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 02d6b6d..218d94d 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -1414,6 +1414,9 @@ static void call_console_drivers(int level, const char *text, size_t len) if (!cpu_online(smp_processor_id()) && !(con->flags & CON_ANYTIME)) continue; + if (con->loglevel && !ignore_loglevel && + level >= con->loglevel) + continue; con->write(con, text, len); } } @@ -1925,6 +1928,33 @@ asmlinkage __visible void early_printk(const char *fmt, ...) } #endif + +char *setup_per_console_loglevel(struct console_cmdline *con, char *options) +{ + int size = options ? strlen(options) : 0; + + if (size >= 3 && + options[size - 3] == 'l' && + options[size - 2] == 'l' && + options[size - 1] >= '1' && options[size - 1] <= '9') { + con->loglevel = options[size - 1] - '0'; + + /* Catch if the user added a comma after some serial console + * options, + * i.e. console=ttyS0,9600n8,ll3 + * the first comma is gone at this point, but we need to delete + * the second one. + */ + if (size > 3 && options[size - 4] == ',') + options[size - 4] = 0; + else + options[size - 3] = 0; + } else + con->loglevel = 0; + + return options; +} + static int __add_preferred_console(char *name, int idx, char *options, char *brl_options) { @@ -1949,12 +1979,15 @@ static int __add_preferred_console(char *name, int idx, char *options, if (!brl_options) selected_console = i; strlcpy(c->name, name, sizeof(c->name)); - c->options = options; + + c->options = setup_per_console_loglevel(c, options); + braille_set_options(c, brl_options); c->index = idx; return 0; } + /* * Set up a console. Called via do_early_param() in init/main.c * for each "console=" parameter in the boot command line. @@ -2478,6 +2511,8 @@ void register_console(struct console *newcon) if (newcon->setup && newcon->setup(newcon, console_cmdline[i].options) != 0) break; + + newcon->loglevel = c->loglevel; newcon->flags |= CON_ENABLED; newcon->index = c->index; if (i == selected_console) { -- 1.9.1 -- 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/