Currently kdump service is restarted even when any new file is added in cpu subsystem. So, it can be restarted multiple times in the cases like loading of acpi_cpufreq module or online/offline of any cpu.
However, we should see kdump service restart only once in case a new CPU is added or removed. cpu crash notes buffer is created when a new CPU is added. It's location does not change when a CPU is onlined/offlined or acpi_cpufreq driver is loaded. Therefore, no need to restart kdump service in such cases.
IMO, there is only one processor driver (drivers/acpi/processor_core.c) which can enumerate a hot added cpu. An `udevadm info` enquiry to acpi device created by this driver gives: # udevadm info -a -p /sys/bus/acpi/devices/LNXCPU:00/ looking at device '/devices/LNXSYSTM:00/LNXSYBUS:00/ACPI0010:00/LNXCPU:00': KERNEL=="LNXCPU:00" SUBSYSTEM=="acpi"
Therefore, this patch modifies the rule to filter such devices.
Signed-off-by: Pratyush Anand panand@redhat.com --- 98-kexec.rules | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/98-kexec.rules b/98-kexec.rules index e32ee13cb2e8..d43760e38f8f 100644 --- a/98-kexec.rules +++ b/98-kexec.rules @@ -1,4 +1,4 @@ -SUBSYSTEM=="cpu", ACTION=="add", PROGRAM="/bin/systemctl try-restart kdump.service" -SUBSYSTEM=="cpu", ACTION=="remove", PROGRAM="/bin/systemctl try-restart kdump.service" +SUBSYSTEM=="acpi", ACTION=="add", KERNEL=="LNXCPU*", PROGRAM="/etc/init.d/kdump condrestart" +SUBSYSTEM=="acpi", ACTION=="remove", KERNEL=="LNXCPU*", PROGRAM="/etc/init.d/kdump condrestart" SUBSYSTEM=="memory", ACTION=="online", PROGRAM="/bin/systemctl try-restart kdump.service" SUBSYSTEM=="memory", ACTION=="offline", PROGRAM="/bin/systemctl try-restart kdump.service"
On Monday 17 July 2017 09:37 AM, Pratyush Anand wrote:
Currently kdump service is restarted even when any new file is added in cpu subsystem. So, it can be restarted multiple times in the cases like loading of acpi_cpufreq module or online/offline of any cpu.
However, we should see kdump service restart only once in case a new CPU is added or removed. cpu crash notes buffer is created when a new CPU is added. It's location does not change when a CPU is onlined/offlined or acpi_cpufreq driver is loaded. Therefore, no need to restart kdump service in such cases.
IMO, there is only one processor driver (drivers/acpi/processor_core.c) which can enumerate a hot added cpu. An `udevadm info` enquiry to acpi device created by this driver gives: # udevadm info -a -p /sys/bus/acpi/devices/LNXCPU:00/ looking at device '/devices/LNXSYSTM:00/LNXSYBUS:00/ACPI0010:00/LNXCPU:00': KERNEL=="LNXCPU:00" SUBSYSTEM=="acpi"
Therefore, this patch modifies the rule to filter such devices.
Signed-off-by: Pratyush Anand panand@redhat.com
98-kexec.rules | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/98-kexec.rules b/98-kexec.rules index e32ee13cb2e8..d43760e38f8f 100644 --- a/98-kexec.rules +++ b/98-kexec.rules @@ -1,4 +1,4 @@ -SUBSYSTEM=="cpu", ACTION=="add", PROGRAM="/bin/systemctl try-restart kdump.service" -SUBSYSTEM=="cpu", ACTION=="remove", PROGRAM="/bin/systemctl try-restart kdump.service" +SUBSYSTEM=="acpi", ACTION=="add", KERNEL=="LNXCPU*", PROGRAM="/etc/init.d/kdump condrestart" +SUBSYSTEM=="acpi", ACTION=="remove", KERNEL=="LNXCPU*", PROGRAM="/etc/init.d/kdump condrestart"
It looks like that following works as well, not sure why we did not see any kdump restart earlier with these rules.
SUBSYSTEM=="cpu", ACTION=="add", KERNEL=="cpu[0-9]*", PROGRAM="/etc/init.d/kdump condrestart" SUBSYSTEM=="cpu", ACTION=="remove", KERNEL=="cpu[0-9]*", PROGRAM="/etc/init.d/kdump condrestart"
So, IMO these should be a better choice for rule which should work on none-acpi platform as well.
SUBSYSTEM=="memory", ACTION=="online", PROGRAM="/bin/systemctl try-restart kdump.service" SUBSYSTEM=="memory", ACTION=="offline", PROGRAM="/bin/systemctl try-restart kdump.service"
On 07/17/2017 at 07:50 PM, Pratyush Anand wrote:
On Monday 17 July 2017 09:37 AM, Pratyush Anand wrote:
Currently kdump service is restarted even when any new file is added in cpu subsystem. So, it can be restarted multiple times in the cases like loading of acpi_cpufreq module or online/offline of any cpu.
However, we should see kdump service restart only once in case a new CPU is added or removed. cpu crash notes buffer is created when a new CPU is added. It's location does not change when a CPU is onlined/offlined or acpi_cpufreq driver is loaded. Therefore, no need to restart kdump service in such cases.
IMO, there is only one processor driver (drivers/acpi/processor_core.c) which can enumerate a hot added cpu. An `udevadm info` enquiry to acpi device created by this driver gives: # udevadm info -a -p /sys/bus/acpi/devices/LNXCPU:00/ looking at device '/devices/LNXSYSTM:00/LNXSYBUS:00/ACPI0010:00/LNXCPU:00': KERNEL=="LNXCPU:00" SUBSYSTEM=="acpi"
Therefore, this patch modifies the rule to filter such devices.
Signed-off-by: Pratyush Anand panand@redhat.com
98-kexec.rules | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/98-kexec.rules b/98-kexec.rules index e32ee13cb2e8..d43760e38f8f 100644 --- a/98-kexec.rules +++ b/98-kexec.rules @@ -1,4 +1,4 @@ -SUBSYSTEM=="cpu", ACTION=="add", PROGRAM="/bin/systemctl try-restart kdump.service" -SUBSYSTEM=="cpu", ACTION=="remove", PROGRAM="/bin/systemctl try-restart kdump.service" +SUBSYSTEM=="acpi", ACTION=="add", KERNEL=="LNXCPU*", PROGRAM="/etc/init.d/kdump condrestart" +SUBSYSTEM=="acpi", ACTION=="remove", KERNEL=="LNXCPU*", PROGRAM="/etc/init.d/kdump condrestart"
It looks like that following works as well, not sure why we did not see any kdump restart earlier with these rules.
SUBSYSTEM=="cpu", ACTION=="add", KERNEL=="cpu[0-9]*", PROGRAM="/etc/init.d/kdump condrestart" SUBSYSTEM=="cpu", ACTION=="remove", KERNEL=="cpu[0-9]*", PROGRAM="/etc/init.d/kdump condrestart"
Seeing "/etc/init.d/kdump condrestart", I guess it's for RHEL6, right? If so, I think no need to send to Fedora first.
Regards, Xunlei
So, IMO these should be a better choice for rule which should work on none-acpi platform as well.
SUBSYSTEM=="memory", ACTION=="online", PROGRAM="/bin/systemctl try-restart kdump.service" SUBSYSTEM=="memory", ACTION=="offline", PROGRAM="/bin/systemctl try-restart kdump.service"
On Wednesday 19 July 2017 08:12 AM, Xunlei Pang wrote:
On 07/17/2017 at 07:50 PM, Pratyush Anand wrote:
On Monday 17 July 2017 09:37 AM, Pratyush Anand wrote:
Currently kdump service is restarted even when any new file is added in cpu subsystem. So, it can be restarted multiple times in the cases like loading of acpi_cpufreq module or online/offline of any cpu.
However, we should see kdump service restart only once in case a new CPU is added or removed. cpu crash notes buffer is created when a new CPU is added. It's location does not change when a CPU is onlined/offlined or acpi_cpufreq driver is loaded. Therefore, no need to restart kdump service in such cases.
IMO, there is only one processor driver (drivers/acpi/processor_core.c) which can enumerate a hot added cpu. An `udevadm info` enquiry to acpi device created by this driver gives: # udevadm info -a -p /sys/bus/acpi/devices/LNXCPU:00/ looking at device '/devices/LNXSYSTM:00/LNXSYBUS:00/ACPI0010:00/LNXCPU:00': KERNEL=="LNXCPU:00" SUBSYSTEM=="acpi"
Therefore, this patch modifies the rule to filter such devices.
Signed-off-by: Pratyush Anand panand@redhat.com
98-kexec.rules | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/98-kexec.rules b/98-kexec.rules index e32ee13cb2e8..d43760e38f8f 100644 --- a/98-kexec.rules +++ b/98-kexec.rules @@ -1,4 +1,4 @@ -SUBSYSTEM=="cpu", ACTION=="add", PROGRAM="/bin/systemctl try-restart kdump.service" -SUBSYSTEM=="cpu", ACTION=="remove", PROGRAM="/bin/systemctl try-restart kdump.service" +SUBSYSTEM=="acpi", ACTION=="add", KERNEL=="LNXCPU*", PROGRAM="/etc/init.d/kdump condrestart" +SUBSYSTEM=="acpi", ACTION=="remove", KERNEL=="LNXCPU*", PROGRAM="/etc/init.d/kdump condrestart"
It looks like that following works as well, not sure why we did not see any kdump restart earlier with these rules.
SUBSYSTEM=="cpu", ACTION=="add", KERNEL=="cpu[0-9]*", PROGRAM="/etc/init.d/kdump condrestart" SUBSYSTEM=="cpu", ACTION=="remove", KERNEL=="cpu[0-9]*", PROGRAM="/etc/init.d/kdump condrestart"
Seeing "/etc/init.d/kdump condrestart", I guess it's for RHEL6, right?
Yes, it was for RHEL6.
If so, I think no need to send to Fedora first.
I think, We should have for fedora as well, but following..
SUBSYSTEM=="cpu", ACTION=="add", KERNEL=="cpu[0-9]*", PROGRAM="/bin/systemctl try-restart kdump.service" SUBSYSTEM=="cpu", ACTION=="remove", KERNEL=="cpu[0-9]*", PROGRAM="/bin/systemctl try-restart kdump.service"
Regards
-
Pratyush Anand -
Xunlei Pang