File kdump-treat-KDUMP_CPUS-0-as-all-available-CPUs.patch of Package kdump.21349
From: Petr Tesarik <ptesarik@suse.com>
Date: Fri Jun 23 13:43:15 2017 +0200
Subject: Treat KDUMP_CPUS=0 as "all available CPUs"
References: bsc#1036223
Upstream: v0.8.17
Git-commit: 34192abe9a0f5ddbcd580fa52b7fa4400533b9a4
Since SMP after crash is now considered stable, remove the warnings and
make the feature more useful by not requiring a fixed number of CPUs.
Signed-off-by: Petr Tesarik <ptesarik@suse.com>
---
doc/man/kdump.5.txt.in | 7 +++----
init/load.sh | 7 +++++--
kdumptool/calibrate.cc | 6 +++---
kdumptool/savedump.cc | 23 ++++++++++++++---------
kdumptool/savedump.h | 2 +-
sysconfig.kdump.in | 7 +------
6 files changed, 27 insertions(+), 25 deletions(-)
--- a/doc/man/kdump.5.txt.in
+++ b/doc/man/kdump.5.txt.in
@@ -136,13 +136,12 @@ the number of CPUs in your system.
This parameter modifies the _maxcpus_ parameter of the kdump kernel and
the number of *makedumpfile*(8) processes created.
+If the value is zero, all available CPUs are used, i.e. the _maxcpus_
+parameter is not added to the kdump kernel command line.
+
*Note:* This parameter does not work properly for the _ELF_ format,
because *makedumpfile*(8) does not support split _ELF_ dump files.
-*WARNING:* SETTING THIS NUMBER TO A NUMBER HIGHER THAN 1 IS EXPERIMENTAL!
-SOME MACHINES ARE KNOWN TO HANG OR REBOOT RANDOMLY DURING INITIALISATION
-OF THE DUMP KERNEL IF KDUMP_CPUS > 1.
-
Default is 1.
--- a/init/load.sh
+++ b/init/load.sh
@@ -63,14 +63,17 @@ function build_kdump_commandline()
local commandline="$KDUMP_COMMANDLINE"
if [ -z "$commandline" ] ; then
- local nr_cpus=$(cpus_param "$kdump_kernel")
+ local nr_cpus
commandline=$(
remove_from_commandline \
'root|resume|crashkernel|splash|mem|BOOT_IMAGE|showopts|zfcp\.allow_lun_scan|hugepages|acpi_no_memhotplug|cgroup_disable|unknown_nmi_panic|rd\.udev\.children-max' \
< /proc/cmdline)
+ if [ ${KDUMP_CPUS:-1} -ne 0 ] ; then
+ nr_cpus=$(cpus_param "$kdump_kernel")=${KDUMP_CPUS:-1}
+ fi
# Use deadline for saving the memory footprint
commandline="$commandline elevator=deadline sysrq=yes reset_devices acpi_no_memhotplug cgroup_disable=memory"
- commandline="$commandline irqpoll ${nr_cpus}=${KDUMP_CPUS:-1}"
+ commandline="$commandline irqpoll ${nr_cpus}"
commandline="$commandline root=kdump rootflags=bind rd.udev.children-max=8"
case $(uname -i) in
i?86|x86_64)
--- a/kdumptool/calibrate.cc
+++ b/kdumptool/calibrate.cc
@@ -905,10 +905,10 @@ void Calibrate::execute()
}
// Add memory based on CPU count
- unsigned long cpus;
- if (CAN_REDUCE_CPUS) {
+ unsigned long cpus = 0;
+ if (CAN_REDUCE_CPUS)
cpus = config->KDUMP_CPUS.value();
- } else {
+ if (!cpus) {
SystemCPU syscpu;
unsigned long online = syscpu.numOnline();
unsigned long offline = syscpu.numOffline();
--- a/kdumptool/savedump.cc
+++ b/kdumptool/savedump.cc
@@ -41,6 +41,7 @@
#include "identifykernel.h"
#include "email.h"
#include "routable.h"
+#include "calibrate.h"
using std::string;
using std::list;
@@ -60,7 +61,7 @@ using std::ifstream;
SaveDump::SaveDump()
throw ()
: m_dump(DEFAULT_DUMP), m_transfer(NULL), m_usedDirectSave(false),
- m_useMakedumpfile(false), m_useSplit(false), m_nomail(false)
+ m_useMakedumpfile(false), m_split(0), m_nomail(false)
{
Debug::debug()->trace("SaveDump::SaveDump()");
@@ -284,10 +285,15 @@ void SaveDump::saveDump(const RootDirURL
if (noDump)
return; // nothing to be done
+ unsigned long cpus = config->KDUMP_CPUS.value();
+ if (cpus) {
+ SystemCPU syscpu;
+ cpus = syscpu.numOnline();
+ }
if (!config->kdumptoolContainsFlag("NOSPLIT") &&
- config->KDUMP_CPUS.value() > 1) {
+ cpus > 1) {
if (!useElf)
- m_useSplit = true;
+ m_split = cpus;
else
cerr << "Splitting ELF dumps is not supported." << endl;
}
@@ -305,7 +311,7 @@ void SaveDump::saveDump(const RootDirURL
// use makedumpfile
ostringstream cmdline;
cmdline << "makedumpfile ";
- if (m_useSplit)
+ if (m_split)
cmdline << "--split ";
cmdline << config->MAKEDUMPFILE_OPTIONS.value() << " ";
cmdline << "-d " << config->KDUMP_DUMPLEVEL.value() << " ";
@@ -340,10 +346,9 @@ void SaveDump::saveDump(const RootDirURL
provider->setProgress(&progress);
else
cout << "Saving dump ..." << endl;
- if (m_useSplit) {
+ if (m_split) {
StringVector targets;
- const int cpus = config->KDUMP_CPUS.value();
- for (int i = 1; i <= cpus; ++i) {
+ for (unsigned long i = 1; i <= m_split; ++i) {
ostringstream ss;
ss << "vmcore" << i;
targets.push_back(ss.str());
@@ -482,8 +487,8 @@ void SaveDump::generateInfo()
ss << "Dump level : "
<< Stringutil::number2string(config->KDUMP_DUMPLEVEL.value()) << endl;
ss << "Dump format : " << config->KDUMP_DUMPFORMAT.value() << endl;
- if (m_useSplit && m_usedDirectSave)
- ss << "Split parts : " << config->KDUMP_CPUS.value() << endl;
+ if (m_split && m_usedDirectSave)
+ ss << "Split parts : " << m_split << endl;
ss << endl;
--- a/kdumptool/savedump.h
+++ b/kdumptool/savedump.h
@@ -112,7 +112,7 @@ class SaveDump : public Subcommand {
Transfer *m_transfer;
bool m_usedDirectSave;
bool m_useMakedumpfile;
- bool m_useSplit;
+ unsigned long m_split;
std::string m_crashtime;
std::string m_crashrelease;
std::string m_rootdir;
--- a/sysconfig.kdump.in
+++ b/sysconfig.kdump.in
@@ -18,13 +18,8 @@ KDUMP_KERNELVER=""
#
# Number of CPUs to be used in the kdump environment. You may want to
# increase the number if computing power is the bottleneck in your setup.
-# This value is used as the maxcpus parameter of the secondary kernel, so
-# DON'T CHANGE IT unless your system can reliably re-initialize SMP after
-# a kernel crash.
#
-# WARNING: SETTING THIS NUMBER TO A NUMBER HIGHER THAN 1 IS EXPERIMENTAL!
-# SOME MACHINES ARE KNOWN TO HANG OR REBOOT RANDOMLY DURING INITIALISATION
-# OF THE DUMP KERNEL IF KDUMP_CPUS > 1.
+# If the value is zero, use all available CPUs.
#
# See also: kdump(5).
#
