Overloading of page fault notification with the notify_die() has performance
issues(since the only interested components for page fault is kprobes and/or
kdb) and hence this patch introduces the new notifier call chain exclusively
for page fault notifications their by avoiding notifying unnecessary
components in the do_page_fault() code path.
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Overloading of page fault notification with the notify_die() has performance
issues(since the only interested components for page fault is kprobes and/or
kdb) and hence this patch introduces the new notifier call chain exclusively
for page fault notifications their by avoiding notifying unnecessary
components in the do_page_fault() code path.
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Overloading of page fault notification with the notify_die() has performance
issues(since the only interested components for page fault is kprobes and/or
kdb) and hence this patch introduces the new notifier call chain exclusively
for page fault notifications their by avoiding notifying unnecessary
components in the do_page_fault() code path.
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Overloading of page fault notification with the notify_die() has performance
issues(since the only interested components for page fault is kprobes and/or
kdb) and hence this patch introduces the new notifier call chain exclusively
for page fault notifications their by avoiding notifying unnecessary
components in the do_page_fault() code path.
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Currently in the do_page_fault() code path, we call notify_die(DIE_PAGE_FAULT,
...) to notify the page fault. Since notify_die() is highly overloaded, this
page fault notification is currently being sent to all the components
registered with register_die_notification() which uses the same die_chain to
loop for all the registered components which is unnecessary.
In order to optimize the do_page_fault() code path, this critical page fault
notification is now moved to different call chain and the test results showed
great improvements.
And the kprobes which is interested in this notifications, now registers onto
this new call chain only when it need to, i.e Kprobes now registers for page
fault notification only when their are an active probes and unregisters from
this page fault notification when no probes are active.
I have incorporated all the feedback given by Ananth and Keith and everyone,
and thanks for all the review feedback.
This patch:
Overloading of page fault notification with the notify_die() has performance
issues(since the only interested components for page fault is kprobes and/or
kdb) and hence this patch introduces the new notifier call chain exclusively
for page fault notifications their by avoiding notifying unnecessary
components in the do_page_fault() code path.
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
If there are multi kprobes on the same probepoint, there will be one extra
aggr_kprobe on the head of kprobe list. The aggr_kprobe has
aggr_post_handler/aggr_break_handler whether the other kprobe
post_hander/break_handler is NULL or not. This patch modifies this, only
when there is one or more kprobe in the list whose post_handler is not
NULL, post_handler of aggr_kprobe will be set as aggr_post_handler.
[soshima@redhat.com: !CONFIG_PREEMPT fix]
Signed-off-by: bibo, mao <bibo.mao@intel.com>
Cc: Masami Hiramatsu <hiramatu@sdl.hitachi.co.jp>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: "Keshavamurthy, Anil S" <anil.s.keshavamurthy@intel.com>
Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Yumiko Sugita <sugita@sdl.hitachi.co.jp>
Cc: Hideo Aoki <haoki@redhat.com>
Signed-off-by: Satoshi Oshima <soshima@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This fixes the clock source updates in update_wall_time() to correctly
track the time coming in via current_tick_length(). Optimize the fast
paths to be as short as possible to keep the overhead low.
Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Acked-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Here is the PIT fix against the TOD patches that Tim pointed out. Many
thanks to Tim for hunting this down.
Cc: Tim Mann <mann@vmware.com>
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add a CLOCKSOURCE_MASK macro to simplify initializing the mask for a struct
clocksource, and use it to replace literal mask constants in the various
clocksource drivers.
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Acked-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
- written on init only, accessed for every timer read --> __read_mostly
- fix broken sentence
Signed-off-by: Andreas Mohr <andi@lisas.de>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
As suggested by Roman Zippel, change clocksource functions to use
clocksource_xyz rather then xyz_clocksource to avoid polluting the
namespace.
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Implement the time sources for i386 (acpi_pm, cyclone, hpet, pit, and tsc).
With this patch, the conversion of the i386 arch to the generic timekeeping
code should be complete.
The patch should be fairly straight forward, only adding the new clocksources.
[hirofumi@mail.parknet.co.jp: acpi_pm cleanup]
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Remove the old timers/timer_opts infrastructure which has been disabled. It
is a fairly straightforward set of deletions
Note that this does not provide any i386 clocksources, so you will only have
the jiffies clocksource. To get full replacements for the code being removed
here, the timeofday-clocks-i386 patch will be needed.
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This converts the i386 arch to use the generic timeofday subsystem. It
enabled the GENERIC_TIME option, disables the timer_opts code and other arch
specific timekeeping code and reworks the delay code.
While this patch enables the generic timekeeping, please note that this patch
does not provide any i386 clocksource. Thus only the jiffies clocksource will
be available. To get full replacements for the code being disabled here, the
timeofday-clocks-i386 patch will needed.
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
As part of the i386 conversion to the generic timekeeping infrastructure, this
introduces a new tsc.c file. The code in this file replaces the TSC
initialization, management and access code currently in timer_tsc.c (which
will be removed) that we want to preserve.
The code also introduces the following functionality:
o tsc_khz: like cpu_khz but stores the TSC frequency on systems that do not
change TSC frequency w/ CPU frequency
o check/mark_tsc_unstable: accessor/modifier flag for TSC timekeeping
usability
o minor cleanups to calibration math.
This patch also includes a one line __cpuinitdata fix from Zwane Mwaikambo.
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
A simple cleanup for the i386 arch in preparation of moving to the generic
timeofday infrastructure. It simply moves the PIT initialization code, locks,
and other code we want to keep from some code from timer_pit.c (which will be
removed) to i8253.c.
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Change the current_tick_length() function so it takes an argument which
specifies how much precision to return in shifted nanoseconds. This provides
a simple way to convert between NTPs internal nanoseconds shifted by
(SHIFT_SCALE - 10) to other shifted nanosecond units that are used by the
clocksource abstraction.
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
nmi_create_files() in arch/i386/oprofile/nmi_int.c depends on
model->num_counters (number of performance counters) being less than 10.
While this is currently the case, it's too clever by half.
Other archs aren't quite as clever: they assume 100. I suggest to
normalize them all to 1000.
Cc: Philippe Elie <phil.el@wanadoo.fr>
Cc: John Levon <levon@movementarian.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Here is a patch to the system call handling for 5307/5272/etc to:
- fix the strace support (one tested the wrong bit)
- make all system calls a little bit faster by inlining set_esp0 and
supporting ENOSYS out of the critical path.
- remove extraneous spaces
Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Remove list of fixed clock frequency options used for configuring master
clock, and make field an int. Much more flexible this way, no need to add
more options for every new used freqency.
Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
