[v3] printk: add option to print cpu id

Message ID	1344013004-32211-1-git-send-email-vikram.pandita@ti.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-omap-owner@vger.kernel.org> From: Vikram Pandita <vikram.pandita@ti.com> To: <gregkh@linuxfoundation.org>, <kay@vrfy.org> CC: <linux-kernel@vger.kernel.org>, <linux-omap@vger.kernel.org>, <linux-arm-kernel@lists.infradead.org>, Vikram Pandita <vikram.pandita@ti.com>, Mike Turquette <mturquette@linaro.org>, Vimarsh Zutshi <vimarsh.zutshi@gmail.com> Subject: [PATCH v3] printk: add option to print cpu id Date: Fri, 3 Aug 2012 09:56:44 -0700 Message-ID: <1344013004-32211-1-git-send-email-vikram.pandita@ti.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-omap-owner@vger.kernel.org Precedence: bulk

diff --git a/kernel/printk.c b/kernel/printk.c index 6a76ab9..90d49b2 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -208,6 +208,7 @@ struct log { u8 facility; /* syslog facility */ u8 flags:5; /* internal record flags */ u8 level:3; /* syslog level */ + u16 cpuid; /* cpu invoking the log */ }; /* @@ -305,7 +306,8 @@ static u32 log_next(u32 idx) static void log_store(int facility, int level, enum log_flags flags, u64 ts_nsec, const char *dict, u16 dict_len, - const char *text, u16 text_len) + const char *text, u16 text_len, + const u16 cpuid) { struct log *msg; u32 size, pad_len; @@ -356,6 +358,7 @@ static void log_store(int facility, int level, msg->ts_nsec = local_clock(); memset(log_dict(msg) + dict_len, 0, pad_len); msg->len = sizeof(struct log) + text_len + dict_len + pad_len; + msg->cpuid = cpuid; /* insert message */ log_next_idx += msg->len; @@ -855,6 +858,25 @@ static size_t print_time(u64 ts, char *buf) (unsigned long)ts, rem_nsec / 1000); } +#if defined(CONFIG_PRINTK_CPUID) +static bool printk_cpuid = 1; +#else +static bool printk_cpuid; +#endif +module_param_named(cpuid, printk_cpuid, bool, S_IRUGO | S_IWUSR); + +static size_t print_cpuid(u16 cpuid, char *buf) +{ + + if (!printk_cpuid) + return 0; + + if (!buf) + return 7; + + return sprintf(buf, "[%4d] ", cpuid); +} + static size_t print_prefix(const struct log *msg, bool syslog, char *buf) { size_t len = 0; @@ -874,6 +896,7 @@ static size_t print_prefix(const struct log *msg, bool syslog, char *buf) } } + len += print_cpuid(msg->cpuid, buf ? buf + len : NULL); len += print_time(msg->ts_nsec, buf ? buf + len : NULL); return len; } @@ -1387,6 +1410,7 @@ static struct cont { u64 ts_nsec; /* time of first print */ u8 level; /* log level of first message */ u8 facility; /* log level of first message */ + u16 cpuid; /* cpu invoking the logging request */ enum log_flags flags; /* prefix, newline flags */ bool flushed:1; /* buffer sealed and committed */ } cont; @@ -1405,7 +1429,8 @@ static void cont_flush(enum log_flags flags) * line. LOG_NOCONS suppresses a duplicated output. */ log_store(cont.facility, cont.level, flags | LOG_NOCONS, - cont.ts_nsec, NULL, 0, cont.buf, cont.len); + cont.ts_nsec, NULL, 0, cont.buf, cont.len, + cont.cpuid); cont.flags = flags; cont.flushed = true; } else { @@ -1414,12 +1439,14 @@ static void cont_flush(enum log_flags flags) * just submit it to the store and free the buffer. */ log_store(cont.facility, cont.level, flags, 0, - NULL, 0, cont.buf, cont.len); + NULL, 0, cont.buf, cont.len, + cont.cpuid); cont.len = 0; } } -static bool cont_add(int facility, int level, const char *text, size_t len) +static bool cont_add(int facility, int level, const char *text, size_t len, + const u16 cpuid) { if (cont.len && cont.flushed) return false; @@ -1442,6 +1469,7 @@ static bool cont_add(int facility, int level, const char *text, size_t len) memcpy(cont.buf + cont.len, text, len); cont.len += len; + cont.cpuid = cpuid; if (cont.len > (sizeof(cont.buf) * 80) / 100) cont_flush(LOG_CONT); @@ -1455,7 +1483,8 @@ static size_t cont_print_text(char *text, size_t size) size_t len; if (cont.cons == 0 && (console_prev & LOG_NEWLINE)) { - textlen += print_time(cont.ts_nsec, text); + textlen += print_cpuid(cont.cpuid, text); + textlen += print_time(cont.ts_nsec, text + textlen); size -= textlen; } @@ -1527,7 +1556,7 @@ asmlinkage int vprintk_emit(int facility, int level, printed_len += strlen(recursion_msg); /* emit KERN_CRIT message */ log_store(0, 2, LOG_PREFIX|LOG_NEWLINE, 0, - NULL, 0, recursion_msg, printed_len); + NULL, 0, recursion_msg, printed_len, this_cpu); } /* @@ -1577,9 +1606,9 @@ asmlinkage int vprintk_emit(int facility, int level, cont_flush(LOG_NEWLINE); /* buffer line if possible, otherwise store it right away */ - if (!cont_add(facility, level, text, text_len)) + if (!cont_add(facility, level, text, text_len, this_cpu)) log_store(facility, level, lflags | LOG_CONT, 0, - dict, dictlen, text, text_len); + dict, dictlen, text, text_len, this_cpu); } else { bool stored = false; @@ -1591,13 +1620,15 @@ asmlinkage int vprintk_emit(int facility, int level, */ if (cont.len && cont.owner == current) { if (!(lflags & LOG_PREFIX)) - stored = cont_add(facility, level, text, text_len); + stored = cont_add(facility, level, text, text_len, + this_cpu); cont_flush(LOG_NEWLINE); } if (!stored) log_store(facility, level, lflags, 0, - dict, dictlen, text, text_len); + dict, dictlen, text, text_len, + this_cpu); } printed_len += text_len; diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 2403a63..139b2b1 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -14,6 +14,19 @@ config PRINTK_TIME The behavior is also controlled by the kernel command line parameter printk.time=1. See Documentation/kernel-parameters.txt +config PRINTK_CPUID + bool "Show cpu id information on printks" + depends on PRINTK + help + Selecting this option causes cpu identifier to be added to the + output of the syslog() system call and at the console. + + This flag just specifies if the cpu-id should + be included. + + The behavior is also controlled by the kernel command line + parameter printk.cpuid=1. + config DEFAULT_MESSAGE_LOGLEVEL int "Default message log level (1-7)" range 1 7

[v3] printk: add option to print cpu id

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