We have added *wdt in kdump initramfs, but to improve it more we can do below (1) load wdt drivers as early as possible so that we can save time before wdt timeout some drivers like iTCO_wdt can stop the watchdog while driver initialization, so it can give more chance for kdump. It can save time especially in case some drivers take long time to init, like some storage and networking cards. (2) add only used wdt drivers in kdump initrd instead of add *wdt wdt driver layer need a change so that we can get the proper driver name from /dev/watchdog. Question to this is are we sure 1st kernel use /dev/watchdog instead of /dev/watchdog1? It need more investigation. (3) in case a driver can not stop (nowayout?) during module_init, we need load it as early as possible and kick the watchdog. Likely we can use systemd default watchdog functionality.
This patch is about to address (1), and specially for iTCO_wdt, we only tested iTCO_wdt, thus in this patch only add this driver, need investigate on other drivers later to see if other drivers works in this way.
Signed-off-by: Dave Young dyoung@redhat.com Signed-off-by: Baoquan He bhe@redhat.com --- dracut-module-setup.sh | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- kexec-tools.orig/dracut-module-setup.sh +++ kexec-tools/dracut-module-setup.sh @@ -666,7 +666,8 @@ install() { installkernel() { wdt=$(lsmod|cut -f1 -d' '|grep "wdt$") if [ -n "$wdt" ]; then - [ "$wdt" = "iTCO_wdt" ] && instmods lpc_ich + [ "$wdt" = "iTCO_wdt" ] && instmods lpc_ich && + echo "rd.driver.pre=lpc_ich,iTCO_wdt " >> ${initdir}/etc/cmdline.d/00-wdt.conf instmods $wdt fi }
Baoquan/Minfei,
Can you review and ack the patch if it is good?
On 07/23/15 at 04:48pm, Dave Young wrote:
We have added *wdt in kdump initramfs, but to improve it more we can do below (1) load wdt drivers as early as possible so that we can save time before wdt timeout some drivers like iTCO_wdt can stop the watchdog while driver initialization, so it can give more chance for kdump. It can save time especially in case some drivers take long time to init, like some storage and networking cards. (2) add only used wdt drivers in kdump initrd instead of add *wdt wdt driver layer need a change so that we can get the proper driver name from /dev/watchdog. Question to this is are we sure 1st kernel use /dev/watchdog instead of /dev/watchdog1? It need more investigation. (3) in case a driver can not stop (nowayout?) during module_init, we need load it as early as possible and kick the watchdog. Likely we can use systemd default watchdog functionality.
This patch is about to address (1), and specially for iTCO_wdt, we only tested iTCO_wdt, thus in this patch only add this driver, need investigate on other drivers later to see if other drivers works in this way.
Signed-off-by: Dave Young dyoung@redhat.com Signed-off-by: Baoquan He bhe@redhat.com
dracut-module-setup.sh | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- kexec-tools.orig/dracut-module-setup.sh +++ kexec-tools/dracut-module-setup.sh @@ -666,7 +666,8 @@ install() { installkernel() { wdt=$(lsmod|cut -f1 -d' '|grep "wdt$") if [ -n "$wdt" ]; then
[ "$wdt" = "iTCO_wdt" ] && instmods lpc_ich
[ "$wdt" = "iTCO_wdt" ] && instmods lpc_ich &&echo "rd.driver.pre=lpc_ich,iTCO_wdt " >> ${initdir}/etc/cmdline.d/00-wdt.conf instmods $wdt} _______________________________________________ kexec mailing list kexec@lists.fedoraproject.org https://lists.fedoraproject.org/mailman/listinfo/kexec
On 07/23/15 at 04:48pm, Dave Young wrote:
We have added *wdt in kdump initramfs, but to improve it more we can do below (1) load wdt drivers as early as possible so that we can save time before wdt timeout some drivers like iTCO_wdt can stop the watchdog while driver initialization, so it can give more chance for kdump. It can save time especially in case some drivers take long time to init, like some storage and networking cards. (2) add only used wdt drivers in kdump initrd instead of add *wdt wdt driver layer need a change so that we can get the proper driver name from /dev/watchdog. Question to this is are we sure 1st kernel use /dev/watchdog instead of /dev/watchdog1? It need more investigation. (3) in case a driver can not stop (nowayout?) during module_init, we need load it as early as possible and kick the watchdog. Likely we can use systemd default watchdog functionality.
This patch is about to address (1), and specially for iTCO_wdt, we only tested iTCO_wdt, thus in this patch only add this driver, need investigate on other drivers later to see if other drivers works in this way.
Once we load the iTCO_wdt and lpc_ich module as earlier as possible, do they have side effect for the 2nd kernel?
Thanks Minfei
Signed-off-by: Dave Young dyoung@redhat.com Signed-off-by: Baoquan He bhe@redhat.com
dracut-module-setup.sh | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- kexec-tools.orig/dracut-module-setup.sh +++ kexec-tools/dracut-module-setup.sh @@ -666,7 +666,8 @@ install() { installkernel() { wdt=$(lsmod|cut -f1 -d' '|grep "wdt$") if [ -n "$wdt" ]; then
[ "$wdt" = "iTCO_wdt" ] && instmods lpc_ich
[ "$wdt" = "iTCO_wdt" ] && instmods lpc_ich &&echo "rd.driver.pre=lpc_ich,iTCO_wdt " >> ${initdir}/etc/cmdline.d/00-wdt.conf instmods $wdt} _______________________________________________ kexec mailing list kexec@lists.fedoraproject.org https://lists.fedoraproject.org/mailman/listinfo/kexec
On 07/25/15 at 01:43pm, Minfei Huang wrote:
On 07/23/15 at 04:48pm, Dave Young wrote:
We have added *wdt in kdump initramfs, but to improve it more we can do below (1) load wdt drivers as early as possible so that we can save time before wdt timeout some drivers like iTCO_wdt can stop the watchdog while driver initialization, so it can give more chance for kdump. It can save time especially in case some drivers take long time to init, like some storage and networking cards. (2) add only used wdt drivers in kdump initrd instead of add *wdt wdt driver layer need a change so that we can get the proper driver name from /dev/watchdog. Question to this is are we sure 1st kernel use /dev/watchdog instead of /dev/watchdog1? It need more investigation. (3) in case a driver can not stop (nowayout?) during module_init, we need load it as early as possible and kick the watchdog. Likely we can use systemd default watchdog functionality.
This patch is about to address (1), and specially for iTCO_wdt, we only tested iTCO_wdt, thus in this patch only add this driver, need investigate on other drivers later to see if other drivers works in this way.
Once we load the iTCO_wdt and lpc_ich module as earlier as possible, do they have side effect for the 2nd kernel?
There's no side effect. Actually moving wdt other than iTCO to early phase is also safe, just only tested iTCO.
Thanks Dave
Thanks Dave.
Acked-by: Minfei Huang mhuang@redhat.com
Thanks Minfei
On 07/27/15 at 08:46am, Dave Young wrote:
On 07/25/15 at 01:43pm, Minfei Huang wrote:
On 07/23/15 at 04:48pm, Dave Young wrote:
We have added *wdt in kdump initramfs, but to improve it more we can do below (1) load wdt drivers as early as possible so that we can save time before wdt timeout some drivers like iTCO_wdt can stop the watchdog while driver initialization, so it can give more chance for kdump. It can save time especially in case some drivers take long time to init, like some storage and networking cards. (2) add only used wdt drivers in kdump initrd instead of add *wdt wdt driver layer need a change so that we can get the proper driver name from /dev/watchdog. Question to this is are we sure 1st kernel use /dev/watchdog instead of /dev/watchdog1? It need more investigation. (3) in case a driver can not stop (nowayout?) during module_init, we need load it as early as possible and kick the watchdog. Likely we can use systemd default watchdog functionality.
This patch is about to address (1), and specially for iTCO_wdt, we only tested iTCO_wdt, thus in this patch only add this driver, need investigate on other drivers later to see if other drivers works in this way.
Once we load the iTCO_wdt and lpc_ich module as earlier as possible, do they have side effect for the 2nd kernel?
There's no side effect. Actually moving wdt other than iTCO to early phase is also safe, just only tested iTCO.
Thanks Dave
-
Dave Young -
Minfei Huang