https://github.com/torvalds/linux
Revision 783e391b7b5b273cd20856d8f6f4878da8ec31b3 authored by Venki Pallipadi on 10 April 2008, 16:49:58 UTC, committed by Linus Torvalds on 10 April 2008, 22:38:29 UTC
This patch also resolves hangs on boot:
	http://lkml.org/lkml/2008/2/23/263
	http://bugzilla.kernel.org/show_bug.cgi?id=10093

The bug was causing once-in-few-reboots 10-15 sec wait during boot on
certain laptops.

Earlier commit 40d6a146629b98d8e322b6f9332b182c7cbff3df added
smp_call_function in cpu_idle_wait() to kick cpus that are in tickless
idle.  Looking at cpu_idle_wait code at that time, code seemed to be
over-engineered for a case which is rarely used (while changing idle
handler).

Below is a simplified version of cpu_idle_wait, which just makes a dummy
smp_call_function to all cpus, to make them come out of old idle handler
and start using the new idle handler.  It eliminates code in the idle
loop to handle cpu_idle_wait.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent a1e58bb
Raw File
Tip revision: 783e391b7b5b273cd20856d8f6f4878da8ec31b3 authored by Venki Pallipadi on 10 April 2008, 16:49:58 UTC
x86: Simplify cpu_idle_wait
Tip revision: 783e391
REPORTING-BUGS
[Some of this is taken from Frohwalt Egerer's original linux-kernel FAQ]

     What follows is a suggested procedure for reporting Linux bugs. You
aren't obliged to use the bug reporting format, it is provided as a guide
to the kind of information that can be useful to developers - no more.

     If the failure includes an "OOPS:" type message in your log or on
screen please read "Documentation/oops-tracing.txt" before posting your
bug report. This explains what you should do with the "Oops" information
to make it useful to the recipient.

      Send the output to the maintainer of the kernel area that seems to
be involved with the problem, and cc the relevant mailing list. Don't
worry too much about getting the wrong person. If you are unsure send it
to the person responsible for the code relevant to what you were doing.
If it occurs repeatably try and describe how to recreate it. That is
worth even more than the oops itself.  The list of maintainers and
mailing lists is in the MAINTAINERS file in this directory.

      If it is a security bug, please copy the Security Contact listed
in the MAINTAINERS file.  They can help coordinate bugfix and disclosure.
See Documentation/SecurityBugs for more information.

      If you are totally stumped as to whom to send the report, send it to
linux-kernel@vger.kernel.org. (For more information on the linux-kernel
mailing list see http://www.tux.org/lkml/).

This is a suggested format for a bug report sent to the Linux kernel mailing
list. Having a standardized bug report form makes it easier for you not to
overlook things, and easier for the developers to find the pieces of
information they're really interested in. Don't feel you have to follow it.

      First run the ver_linux script included as scripts/ver_linux, which
reports the version of some important subsystems.  Run this script with
the command "sh scripts/ver_linux".

Use that information to fill in all fields of the bug report form, and
post it to the mailing list with a subject of "PROBLEM: <one line
summary from [1.]>" for easy identification by the developers.

[1.] One line summary of the problem:
[2.] Full description of the problem/report:
[3.] Keywords (i.e., modules, networking, kernel):
[4.] Kernel information
[4.1.] Kernel version (from /proc/version):
[4.2.] Kernel .config file:
[5.] Most recent kernel version which did not have the bug:
[6.] Output of Oops.. message (if applicable) with symbolic information
     resolved (see Documentation/oops-tracing.txt)
[7.] A small shell script or example program which triggers the
     problem (if possible)
[8.] Environment
[8.1.] Software (add the output of the ver_linux script here)
[8.2.] Processor information (from /proc/cpuinfo):
[8.3.] Module information (from /proc/modules):
[8.4.] Loaded driver and hardware information (/proc/ioports, /proc/iomem)
[8.5.] PCI information ('lspci -vvv' as root)
[8.6.] SCSI information (from /proc/scsi/scsi)
[8.7.] Other information that might be relevant to the problem
       (please look in /proc and include all information that you
       think to be relevant):
[X.] Other notes, patches, fixes, workarounds:


Thank you
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