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* printk: Add KERN_DEFAULT printk log-levelLinus Torvalds2009-06-16
| | | | | | | | | | | | | | | | | | | This adds a KERN_DEFAULT loglevel marker, for when you cannot decide which loglevel you want, and just want to keep an existing printk with the default loglevel. The difference between having KERN_DEFAULT and having no log-level marker at all is two-fold: - having the log-level marker will now force a new-line if the previous printout had not added one (perhaps because it forgot, but perhaps because it expected a continuation) - having a log-level marker is required if you are printing out a message that otherwise itself could perhaps otherwise be mistaken for a log-level. Signed-of-by: Linus Torvalds <torvalds@linux-foundation.org>
* printk: clean up handling of log-levels and newlinesLinus Torvalds2009-06-16
| | | | | | | | | | | | | | | | | It used to be that we would only look at the log-level in a printk() after explicit newlines, which can cause annoying problems when the previous printk() did not end with a '\n'. In that case, the log-level marker would be just printed out in the middle of the line, and be seen as just noise rather than change the logging level. This changes things to always look at the log-level in the first bytes of the printout. If a log level marker is found, it is always used as the log-level. Additionally, if no newline existed, one is added (unless the log-level is the explicit KERN_CONT marker, to explicitly show that it's a continuation of a previous line). Acked-by: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'printk-for-linus' of ↵Linus Torvalds2009-04-05
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'printk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: printk: correct the behavior of printk_timed_ratelimit() vsprintf: unify the format decoding layer for its 3 users, cleanup fix regression from "vsprintf: unify the format decoding layer for its 3 users" vsprintf: fix bug in negative value printing vsprintf: unify the format decoding layer for its 3 users vsprintf: add binary printf printk: introduce printk_once() Fix trivial conflicts (printk_once vs log_buf_kexec_setup() added near each other) in include/linux/kernel.h.
| * printk: correct the behavior of printk_timed_ratelimit()Guillaume Knispel2009-03-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: fix jiffies-comparison sign-wrap behavior The behavior provided by printk_timed_ratelimit() is, in some situations, probably not what a caller would reasonably expect: bool printk_timed_ratelimit(unsigned long *caller_jiffies, unsigned int interval_msecs) { if (*caller_jiffies == 0 || time_after(jiffies, *caller_jiffies)) { *caller_jiffies = jiffies + msecs_to_jiffies(interval_msecs); return true; } return false; } On a 32 bit computer, if printk_timed_ratelimit() is initially called at time jiffies == Ja, *caller_jiffies is set to Ja + msecs_to_jiffies(interval_msecs): let's say Ja + 42 for this example. If this caller then doesn't call printk_timed_ratelimit() until jiffies == Ja + (1 << 31) + 42 (which can happen as soon as ~ 25 days later on a 1000 HZ system), printk_timed_ratelimit() will then always return false to this caller until jiffies loops completely (1 << 31 more ticks). Ths change makes it only return false if jiffies is in the small time window starting at the previous call when true was returned and ending interval_msecs later. Note that if jiffies loops completely between two calls to printk_timed_ratelimit(), it will obviously still wrongly return false, but this is something with a low probability. If something completely reliable is needed I guess jiffies_64 must be used (which this change does not do). Signed-off-by: Guillaume Knispel <gknispel@proformatique.com> Cc: Ulrich Drepper <drepper@redhat.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Andrew Morton <akpm@osdl.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <20090317161842.0059096b@xilun.lan.proformatique.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | kexec: add dmesg log symbols to /proc/vmcoreinfo listsNeil Horman2009-04-02
|/ | | | | | | | | | | | | | | | | | | | | It would be nice to be able to extract the dmesg log from a vmcore file without needing to keep the debug symbols for the running kernel handy all the time. We have a facility to do this in /proc/vmcore. This patch adds the log_buf and log_end symbols to the vmcoreinfo area so that tools (like makedumpfile) can easily extract the dmesg logs from a vmcore image. [akpm@linux-foundation.org: several fixes and cleanups] [akpm@linux-foundation.org: fix unused log_buf_kexec_setup()] [akpm@linux-foundation.org: build fix] Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Cc: Simon Horman <horms@verge.net.au> Acked-by: Vivek Goyal <vgoyal@redhat.com> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: Simon Horman <horms@verge.net.au> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* PM: Fix suspend_console and resume_console to use only one semaphoreArve Hjønnevåg2009-02-21
| | | | | | | | | | | | | | | | | | | | | | | This fixes a race where a thread acquires the console while the console is suspended, and the console is resumed before this thread releases it. In this case, the secondary console semaphore would be left locked, and the primary semaphore would be released twice. This in turn would cause the console switch on suspend or resume to hang forever. Note that suspend_console does not actually lock the console for clients that use acquire_console_sem, it only locks it for clients that use try_acquire_console_sem. If we change suspend_console to fully lock the console, then the kernel may deadlock on suspend. One client of try_acquire_console_sem is acquire_console_semaphore_for_printk, which uses it to prevent printk from using the console while it is suspended. Signed-off-by: Arve Hjønnevåg <arve@android.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Len Brown <lenb@kernel.org> Cc: Greg KH <gregkh@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [CVE-2009-0029] System call wrappers part 27Heiko Carstens2009-01-14
| | | | Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* [CVE-2009-0029] Make sys_syslog a conditional system callHeiko Carstens2009-01-14
| | | | | | | | Remove the -ENOSYS implementation for !CONFIG_PRINTK and use the cond_syscall infrastructure instead. Acked-by: Kyle McMartin <kyle@redhat.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* trivial: printk: fix indentation of new_text_line declarationJiri Kosina2009-01-06
| | | | | | | | Remove bogus indentation of new_text_line declaration introduced in commit ac60ad741. Acked-by: Nick Andrew <nick@nick-andrew.net> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* printk: fix discarding message when recursion_bugHiroshi Shimamoto2008-12-19
| | | | | | | | | | | | Impact: fix truncated recursion bug message printout When recursion_bug is true, kernel discards original message because printk_buf contains recursion_bug_msg with NULL terminator. The sizeof(recursion_bug_msg) makes this, use strlen() to get correct length without NULL terminator. Reported-by: Toshikazu Nakayama <nakayama.ts@ncos.nec.co.jp> Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* printk: remove unused code from kernel/printk.croel kluin2008-10-23
| | | | | | both log_buf_copy() and log_buf_len are unused. Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Merge branch 'core-v28-for-linus' of ↵Linus Torvalds2008-10-16
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-v28-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: do_generic_file_read: s/EINTR/EIO/ if lock_page_killable() fails softirq, warning fix: correct a format to avoid a warning softirqs, debug: preemption check x86, pci-hotplug, calgary / rio: fix EBDA ioremap() IO resources, x86: ioremap sanity check to catch mapping requests exceeding, fix IO resources, x86: ioremap sanity check to catch mapping requests exceeding the BAR sizes softlockup: Documentation/sysctl/kernel.txt: fix softlockup_thresh description dmi scan: warn about too early calls to dmi_check_system() generic: redefine resource_size_t as phys_addr_t generic: make PFN_PHYS explicitly return phys_addr_t generic: add phys_addr_t for holding physical addresses softirq: allocate less vectors IO resources: fix/remove printk printk: robustify printk, update comment printk: robustify printk, fix #2 printk: robustify printk, fix printk: robustify printk Fixed up conflicts in: arch/powerpc/include/asm/types.h arch/powerpc/platforms/Kconfig.cputype manually.
| *-. Merge branches 'core/softlockup', 'core/softirq', 'core/resources', ↵Ingo Molnar2008-10-15
| |\ \ | | | | | | | | | | | | 'core/printk' and 'core/misc' into core-v28-for-linus
| | | * printk: robustify printk, update commentJiri Kosina2008-08-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove the comment describing the possibility of printk() deadlocking on runqueue lock. Signed-off-by: Jiri Kosina <jkosina@suse.cz> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | | * printk: robustify printk, fix #2Peter Zijlstra2008-08-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Dmitry Adamushko reported: > [*] btw., with DEBUG being enabled, pr_debug() generates [1] when > debug_smp_processor_id() is used (CONFIG_DEBUG_PREEMPT). > > the problem seems to be caused by the following commit: > commit b845b517b5e3706a3729f6ea83b88ab85f0725b0 > Author: Peter Zijlstra <a.p.zijlstra@chello.nl> > Date: Fri Aug 8 21:47:09 2008 +0200 > > printk: robustify printk > > > wake_up_klogd() -> __get_cpu_var() -> smp_processor_id() > > and that's being called from release_console_sem() which is, in turn, > said to be "may be called from any context" [2] > > and in this case, it seems to be called from some non-preemptible > context (although, it can't be printk()... > although, I haven't looked carefully yet). > > Provided [2], __get_cpu_var() is perhaps not the right solution there. > > > [1] > > [ 7697.942005] BUG: using smp_processor_id() in preemptible [00000000] code: syslogd/3542 > [ 7697.942005] caller is wake_up_klogd+0x1b/0x50 > [ 7697.942005] Pid: 3542, comm: syslogd Not tainted 2.6.27-rc3-tip-git #2 > [ 7697.942005] Call Trace: > [ 7697.942005] [<ffffffff8036b398>] debug_smp_processor_id+0xe8/0xf0 > [ 7697.942005] [<ffffffff80239d3b>] wake_up_klogd+0x1b/0x50 > [ 7697.942005] [<ffffffff8023a047>] release_console_sem+0x1e7/0x200 > [ 7697.942005] [<ffffffff803c0f17>] do_con_write+0xb7/0x1f30 > [ 7697.942005] [<ffffffff8020d920>] ? show_trace+0x10/0x20 > [ 7697.942005] [<ffffffff8020dc42>] ? dump_stack+0x72/0x80 > [ 7697.942005] [<ffffffff8036392d>] ? __ratelimit+0xbd/0xe0 > [ 7697.942005] [<ffffffff8036b398>] ? debug_smp_processor_id+0xe8/0xf0 > [ 7697.942005] [<ffffffff80239d3b>] ? wake_up_klogd+0x1b/0x50 > [ 7697.942005] [<ffffffff8023a047>] ? release_console_sem+0x1e7/0x200 > [ 7697.942005] [<ffffffff803c2de9>] con_write+0x19/0x30 > [ 7697.942005] [<ffffffff803b37b6>] write_chan+0x276/0x3c0 > [ 7697.942005] [<ffffffff80232b20>] ? default_wake_function+0x0/0x10 > [ 7697.942005] [<ffffffff804cb872>] ? _spin_lock_irqsave+0x22/0x50 > [ 7697.942005] [<ffffffff803b1334>] tty_write+0x194/0x260 > [ 7697.942005] [<ffffffff803b3540>] ? write_chan+0x0/0x3c0 > [ 7697.942005] [<ffffffff803b14a4>] redirected_tty_write+0xa4/0xb0 > [ 7697.942005] [<ffffffff803b1400>] ? redirected_tty_write+0x0/0xb0 > [ 7697.942005] [<ffffffff802a88c2>] do_loop_readv_writev+0x52/0x80 > [ 7697.942005] [<ffffffff802a939d>] do_readv_writev+0x1bd/0x1d0 > [ 7697.942005] [<ffffffff802a93e9>] vfs_writev+0x39/0x60 > [ 7697.942005] [<ffffffff802a9870>] sys_writev+0x50/0x90 > [ 7697.942005] [<ffffffff8020bb3b>] system_call_fastpath+0x16/0x1b Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reported-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | | * printk: robustify printkPeter Zijlstra2008-08-11
| | |/ | | | | | | | | | | | | | | | | | | | | | Avoid deadlocks against rq->lock and xtime_lock by deferring the klogd wakeup by polling from the timer tick. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | Add kerneldoc documentation for new printk format extensionsAndi Kleen2008-10-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add documentation in kerneldoc for new printk format extensions This patch documents the new %pS/%pF options in printk in kernel doc. Hope I didn't miss any other extension. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | Remove Andrew Morton's old email accountsFrancois Cami2008-10-16
|/ / | | | | | | | | | | | | | | | | People can use the real name an an index into MAINTAINERS to find the current email address. Signed-off-by: Francois Cami <francois.cami@free.fr> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* / tty: Move tty_write_message out of kernel/printkAlan Cox2008-10-13
|/ | | | | | | | This is pure tty code so put it in the tty layer where it can be with the locking relevant material it uses Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* printk: fix comment for printk ratelimitingUwe Kleine-König2008-07-30
| | | | | | | | | | The comment assumed the burst to be one and the ratelimit used to be named printk_ratelimit_jiffies. Signed-off-by: Uwe Kleine-König <Uwe.Kleine-Koenig@digi.com> Cc: Dave Young <hidave.darkstar@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* printk ratelimiting rewriteDave Young2008-07-25
| | | | | | | | | | | | | | | | | | | | | | | | | | All ratelimit user use same jiffies and burst params, so some messages (callbacks) will be lost. For example: a call printk_ratelimit(5 * HZ, 1) b call printk_ratelimit(5 * HZ, 1) before the 5*HZ timeout of a, then b will will be supressed. - rewrite __ratelimit, and use a ratelimit_state as parameter. Thanks for hints from andrew. - Add WARN_ON_RATELIMIT, update rcupreempt.h - remove __printk_ratelimit - use __ratelimit in net_ratelimit Signed-off-by: Dave Young <hidave.darkstar@gmail.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Cc: Dave Young <hidave.darkstar@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* swsusp: provide users with a hint about the no_console_suspend optionPavel Machek2008-07-24
| | | | | | | | | | | Tell the user about the no_console_suspend option, so that we don't have to tell each bug reporter personally. [akpm@linux-foundation.org: clarify the text a little] Signed-off-by: Pavel Machek <pavel@suse.cz> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'core/printk' of ↵Linus Torvalds2008-07-14
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core/printk' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86, generic: mark early_printk as asmlinkage printk: export console_drivers printk: remember the message level for multi-line output printk: refactor processing of line severity tokens printk: don't prefer unsuited consoles on registration printk: clean up recursion check related static variables namespacecheck: more kernel/printk.c fixes namespacecheck: fix kernel printk.c
| * x86, generic: mark early_printk as asmlinkageJiri Slaby2008-06-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | It's not explicitly marked as asmlinkage, but invoked from x86_32 startup code with parameters on stack. No other architectures define early_printk and none of them are affected by this change, since defines asmlinkage as empty token. Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * printk: export console_driversIngo Molnar2008-06-16
| | | | | | | | | | | | this symbol is needed by drivers/video/xen-fbfront.ko. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * printk: remember the message level for multi-line outputNick Andrew2008-05-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | printk(KERN_ALERT "Danger Will Robinson!\nAlien Approaching!\n"); At present this will result in one message at ALERT level and one at the current default message loglevel (e.g. WARNING). This is non-intuitive. Modify vprintk() to remember the message loglevel each time it is specified and use it for subsequent lines of output which do not specify one, within the same call to printk. Signed-off-by: Nick Andrew <nick@nick-andrew.net> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * printk: refactor processing of line severity tokensNick Andrew2008-05-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Restructure the logic of vprintk() so the processing of the leading 3 characters of each input line is in one place, regardless whether printk_time is enabled. This makes the code smaller and easier to understand. size reduction in kernel/printk.o: text data bss dec hex filename 6157 397 1049804 1056358 101e66 printk.o.before 6117 397 1049804 1056318 101e3e printk.o.after and some style uncleanlinesses removed as well as a side-effect: Before: total: 19 errors, 22 warnings, 1340 lines checked After: total: 17 errors, 22 warnings, 1333 lines checked Signed-off-by: Nick Andrew <nick@nick-andrew.net> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * printk: don't prefer unsuited consoles on registrationJan Kiszka2008-05-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | console election: If some console happens to be registered first which does not provide a tty binding (!console->device), it prevents that more suited consoles which are registered later on can enter the candidate pool for console_device(). This is observable with KGDB's console which may already be registered (and exploited!) during early debugger connections, that is before any regular console registration. This patch fixes the issue by postponing the final, automated preferred_console selection until someone with a non-NULL device handler comes around. Signed-off-by: Jan Kiszka <jan.kiszka@web.de> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Gerd Hoffmann <kraxel@suse.de> Cc: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * printk: clean up recursion check related static variablesTejun Heo2008-05-24
| | | | | | | | | | | | | | | | | | Make printk_recursion_bug_msg static and drop printk prefix from recursion variables. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * namespacecheck: more kernel/printk.c fixesThomas Gleixner2008-05-24
| | | | | | | | | | | | | | [ Stephen Rothwell <sfr@canb.auug.org.au>: build fix ] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * namespacecheck: fix kernel printk.cThomas Gleixner2008-05-24
| | | | | | | | | | Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | Merge branch 'auto-ftrace-next' into tracing/for-linusIngo Molnar2008-07-14
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: arch/x86/kernel/entry_32.S arch/x86/kernel/process_32.c arch/x86/kernel/process_64.c arch/x86/lib/Makefile include/asm-x86/irqflags.h kernel/Makefile kernel/sched.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * \ Merge branch 'tracing/ftrace' into auto-ftrace-nextIngo Molnar2008-07-10
| |\ \
| | * | ftrace: trace irq disabled critical timingsSteven Rostedt2008-05-23
| | |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds latency tracing for critical timings (how long interrupts are disabled for). "irqsoff" is added to /debugfs/tracing/available_tracers Note: tracing_max_latency also holds the max latency for irqsoff (in usecs). (default to large number so one must start latency tracing) tracing_thresh threshold (in usecs) to always print out if irqs off is detected to be longer than stated here. If irq_thresh is non-zero, then max_irq_latency is ignored. Here's an example of a trace with ftrace_enabled = 0 ======= preemption latency trace v1.1.5 on 2.6.24-rc7 Signed-off-by: Ingo Molnar <mingo@elte.hu> -------------------------------------------------------------------- latency: 100 us, #3/3, CPU#1 | (M:rt VP:0, KP:0, SP:0 HP:0 #P:2) ----------------- | task: swapper-0 (uid:0 nice:0 policy:0 rt_prio:0) ----------------- => started at: _spin_lock_irqsave+0x2a/0xb7 => ended at: _spin_unlock_irqrestore+0x32/0x5f _------=> CPU# / _-----=> irqs-off | / _----=> need-resched || / _---=> hardirq/softirq ||| / _--=> preempt-depth |||| / ||||| delay cmd pid ||||| time | caller \ / ||||| \ | / swapper-0 1d.s3 0us+: _spin_lock_irqsave+0x2a/0xb7 (e1000_update_stats+0x47/0x64c [e1000]) swapper-0 1d.s3 100us : _spin_unlock_irqrestore+0x32/0x5f (e1000_update_stats+0x641/0x64c [e1000]) swapper-0 1d.s3 100us : trace_hardirqs_on_caller+0x75/0x89 (_spin_unlock_irqrestore+0x32/0x5f) vim:ft=help ======= And this is a trace with ftrace_enabled == 1 ======= preemption latency trace v1.1.5 on 2.6.24-rc7 -------------------------------------------------------------------- latency: 102 us, #12/12, CPU#1 | (M:rt VP:0, KP:0, SP:0 HP:0 #P:2) ----------------- | task: swapper-0 (uid:0 nice:0 policy:0 rt_prio:0) ----------------- => started at: _spin_lock_irqsave+0x2a/0xb7 => ended at: _spin_unlock_irqrestore+0x32/0x5f _------=> CPU# / _-----=> irqs-off | / _----=> need-resched || / _---=> hardirq/softirq ||| / _--=> preempt-depth |||| / ||||| delay cmd pid ||||| time | caller \ / ||||| \ | / swapper-0 1dNs3 0us+: _spin_lock_irqsave+0x2a/0xb7 (e1000_update_stats+0x47/0x64c [e1000]) swapper-0 1dNs3 46us : e1000_read_phy_reg+0x16/0x225 [e1000] (e1000_update_stats+0x5e2/0x64c [e1000]) swapper-0 1dNs3 46us : e1000_swfw_sync_acquire+0x10/0x99 [e1000] (e1000_read_phy_reg+0x49/0x225 [e1000]) swapper-0 1dNs3 46us : e1000_get_hw_eeprom_semaphore+0x12/0xa6 [e1000] (e1000_swfw_sync_acquire+0x36/0x99 [e1000]) swapper-0 1dNs3 47us : __const_udelay+0x9/0x47 (e1000_read_phy_reg+0x116/0x225 [e1000]) swapper-0 1dNs3 47us+: __delay+0x9/0x50 (__const_udelay+0x45/0x47) swapper-0 1dNs3 97us : preempt_schedule+0xc/0x84 (__delay+0x4e/0x50) swapper-0 1dNs3 98us : e1000_swfw_sync_release+0xc/0x55 [e1000] (e1000_read_phy_reg+0x211/0x225 [e1000]) swapper-0 1dNs3 99us+: e1000_put_hw_eeprom_semaphore+0x9/0x35 [e1000] (e1000_swfw_sync_release+0x50/0x55 [e1000]) swapper-0 1dNs3 101us : _spin_unlock_irqrestore+0xe/0x5f (e1000_update_stats+0x641/0x64c [e1000]) swapper-0 1dNs3 102us : _spin_unlock_irqrestore+0x32/0x5f (e1000_update_stats+0x641/0x64c [e1000]) swapper-0 1dNs3 102us : trace_hardirqs_on_caller+0x75/0x89 (_spin_unlock_irqrestore+0x32/0x5f) vim:ft=help ======= Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | | Merge branch 'linus' into x86/coreIngo Molnar2008-07-12
|\| | | | | | | | | | | | | | | | | | | | | | | Conflicts: arch/x86/mm/ioremap.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | kernel/printk.c: Made printk_recursion_bug_msg static.Daniel Guilak2008-07-08
| |/ | | | | | | | | | | Signed-off-by: Daniel Guilak <daniel@danielguilak.com> Acked-by: Josh Triplett <josh@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | printk: export console_driversIngo Molnar2008-07-08
| | | | | | | | | | | | | | | | this symbol is needed by drivers/video/xen-fbfront.ko. [ cherry-picked from tip/core/printk ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | xen: Enable console tty by default in domU if it's not a dummyMarkus Armbruster2008-05-27
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Without console= arguments on the kernel command line, the first console to register becomes enabled and the preferred console (the one behind /dev/console). This is normally tty (assuming CONFIG_VT_CONSOLE is enabled, which it commonly is). This is okay as long tty is a useful console. But unless we have the PV framebuffer, and it is enabled for this domain, tty0 in domU is merely a dummy. In that case, we want the preferred console to be the Xen console hvc0, and we want it without having to fiddle with the kernel command line. Commit b8c2d3dfbc117dff26058fbac316b8acfc2cb5f7 did that for us. Since we now have the PV framebuffer, we want to enable and prefer tty again, but only when PVFB is enabled. But even then we still want to enable the Xen console as well. Problem: when tty registers, we can't yet know whether the PVFB is enabled. By the time we can know (xenstore is up), the console setup game is over. Solution: enable console tty by default, but keep hvc as the preferred console. Change the preferred console to tty when PVFB probes successfully, unless we've been given console kernel parameters. Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* printk: don't read beyond string arguments' terminating zeroMarkus Armbruster2008-04-30
| | | | | | | | | Fix update_console_cmdline() not to to read beyond the terminating zero of its name argument. Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Basic braille screen reader supportSamuel Thibault2008-04-30
| | | | | | | | | | | | | | | This adds a minimalistic braille screen reader support. This is meant to be used by blind people e.g. on boot failures or when / cannot be mounted etc and thus the userland screen readers can not work. [akpm@linux-foundation.org: fix exports] Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org> Cc: Jiri Kosina <jikos@jikos.cz> Cc: Dmitry Torokhov <dtor@mail.ru> Acked-by: Alan Cox <alan@redhat.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: The big operations reworkAlan Cox2008-04-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Operations are now a shared const function block as with most other Linux objects - Introduce wrappers for some optional functions to get consistent behaviour - Wrap put_char which used to be patched by the tty layer - Document which functions are needed/optional - Make put_char report success/fail - Cache the driver->ops pointer in the tty as tty->ops - Remove various surplus lock calls we no longer need - Remove proc_write method as noted by Alexey Dobriyan - Introduce some missing sanity checks where certain driver/ldisc combinations would oops as they didn't check needed methods were present [akpm@linux-foundation.org: fix fs/compat_ioctl.c build] [akpm@linux-foundation.org: fix isicom] [akpm@linux-foundation.org: fix arch/ia64/hp/sim/simserial.c build] [akpm@linux-foundation.org: fix kgdb] Signed-off-by: Alan Cox <alan@redhat.com> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Cc: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* isolate ratelimit from printk.c for other useDave Young2008-04-29
| | | | | | | | | | | | Due to the rcupreempt.h WARN_ON trigged, I got 2G syslog file. For some serious complaining of kernel, we need repeat the warnings, so here I isolate the ratelimit part of printk.c to a standalone file. Signed-off-by: Dave Young <hidave.darkstar@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Fix locking bug in "acquire_console_semaphore_for_printk()"Linus Torvalds2008-04-15
| | | | | | | | | | | | | | | | | | | When I cleaned up printk() and split up the printk locking logic in commit 266c2e0abeca649fa6667a1a427ad1da507c6375 ("Make printk() console semaphore accesses sensible") I had incorrectly moved the call to have_callable_console() outside of the console semaphore. That was buggy. The console semaphore protects the console_drivers list that is used by have_callable_console(). Thanks go to Bongani Hlope who saw this as a hang on shutdown and reboot and bisected the bug to the right commit, and tested this patch. See http://lkml.org/lkml/2008/4/11/315 Bisected-and-tested-by: Bongani Hlope <bonganilinux@mweb.co.za> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Make printk() console semaphore accesses sensibleLinus Torvalds2008-03-24
| | | | | | | | The printk() logic on when/how to get the console semaphore was unreadable, this splits the code up into a few helper functions and makes it easier to follow what is going on. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* printk: fix possible printk overrunTejun Heo2008-02-26
| | | | | | | | | | | | | | | | | | | | | printk recursion detection prepends message to printk_buf and offsets printk_buf when actual message is printed but it forgets to trim buffer length accordingly. This can result in overrun in extreme cases. Fix it. [ mingo@elte.hu: bug was introduced by me via: commit 32a76006683f7b28ae3cc491da37716e002f198e Author: Ingo Molnar <mingo@elte.hu> Date: Fri Jan 25 21:07:58 2008 +0100 printk: make printk more robust by not allowing recursion ] Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* printk_ratelimit() functions should use CONFIG_PRINTKJoe Perches2008-02-08
| | | | | | | | Makes an embedded image a bit smaller. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* The scheduled 'time' option removalAdrian Bunk2008-02-08
| | | | | | | | | The scheduled removal of the 'time' option. Signed-off-by: Adrian Bunk <bunk@kernel.org> Acked-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Nuke duplicate include from printk.cJesper Juhl2008-02-08
| | | | | | | | Remove the duplicate inclusion of linux/jiffies.h from kernel/printk.c Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* printk.c: use unsigned ints instead of longs for logbuf indexDenys Vlasenko2008-02-06
| | | | | | | | | | | | | | | | Stop using unsigned _longs_ for printk buffer indexes. Log buffer is way smaller than 2 gigabytes and unsigned ints will work too . Indeed, they do work nicely on all 32-bit platforms where longs and ints are the same. With this patch, we have following size savings on amd64: text data bss dec hex filename 5997 313 17736 24046 5dee 2.6.23.1.t64/kernel/printk.o 5858 313 17700 23871 5d3f 2.6.23.1.printk.t64/kernel/printk.o Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* debug: turn ignore_loglevel into an early paramIngo Molnar2008-01-31
| | | | | | | i was debugging early crashes and wondered where all the printks went. The reason: ignore_loglevel_setup() was not called yet ... Signed-off-by: Ingo Molnar <mingo@elte.hu>
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