kexec May 2017

kexec@lists.fedoraproject.org

11 participants
20 discussions

[PATCH v2] kdumpctl: eliminate redundant lsinitrd in dracut
by Ziyue Yang 09 May '17

09 May '17

Currently in Fedora/RedHat dracut installs its fedora.conf.example as the default config file, in which sysloglvl is set 5. This leads to maxloglvl=5 in dracut calls, making unnecessary lsinitrd calls during initramfs builds. This patch makes use of --conf and --confdir arguments of dracut, creates temp config directory before mkdumprd(dracut) calls. It appends sysloglvl=0 option by creating a 99-kdumpctl.conf file in the temp config directory. 1) Before this patch $ kdumpctl stop; touch /etc/kdump.conf; time kdumpctl start kexec: unloaded kdump kernel Stopping kdump: [OK] Detected change(s) in the following file(s): /etc/kdump.conf Rebuilding /boot/initramfs-4.10.10-200.fc25.x86_64kdump.img 4.10.10-200.fc25_x86_64 kexec: loaded kdump kernel Starting kdump: [OK] real 0m18.716s user 0m13.863s sys 0m3.269s 2) After this patch $ kdumpctl stop; touch /etc/kdump.conf; time kdumpctl start kexec: unloaded kdump kernel Stopping kdump: [OK] Detected change(s) in the following file(s): /etc/kdump.conf Rebuilding /boot/initramfs-4.10.10-200.fc25.x86_64kdump.img 4.10.10-200.fc25_x86_64 kexec: loaded kdump kernel Starting kdump: [OK] real 0m13.665s user 0m10.945s sys 0m2.907s Signed-off-by: Ziyue Yang <ziyang(a)redhat.com> --- kdumpctl | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/kdumpctl b/kdumpctl index 4d6b3e8..a37db01 100755 --- a/kdumpctl +++ b/kdumpctl @@ -5,7 +5,6 @@ KDUMP_KERNELVER="" KDUMP_COMMANDLINE="" KEXEC_ARGS="" KDUMP_CONFIG_FILE="/etc/kdump.conf" -MKDUMPRD="/sbin/mkdumprd -f" SAVE_PATH=/var/crash SSH_KEY_LOCATION="/root/.ssh/kdump_id_rsa" INITRD_CHECKSUM_LOCATION="/boot/.fadump_initrd_checksum" @@ -20,6 +19,18 @@ DEFAULT_DUMP_MODE="kdump" image_time=0 [[ $dracutbasedir ]] || dracutbasedir=/usr/lib/dracut + +# lower dracut's default sysloglvl to speedup initramfs build +DRACUT_SYSLOGLVL="3" +# make temp dir for dracut conf files +[[ $dracutconfdir ]] || dracutconfdir=/tmp/kdumpctl.dracut.conf +mkdir -p $dracutconfdir/dracut.conf.d +[[ -e $dracutbasedir/dracut.conf.d ]] && cp -rf $dracutbasedir/dracut.conf.d $dracutconfdir/ +[[ -e $dracutbasedir/dracut.conf ]] && cp -rf $dracutbasedir/dracut.conf $dracutconfdir/ +echo "sysloglvl=$DRACUT_SYSLOGLVL" > $dracutconfdir/dracut.conf.d/99-kdumpctl.conf + +MKDUMPRD="/sbin/mkdumprd --conf $dracutconfdir/dracut.conf --confdir $dracutconfdir/dracut.conf.d -f" + . $dracutbasedir/dracut-functions.sh . /lib/kdump/kdump-lib.sh @@ -284,6 +295,9 @@ rebuild_initrd() rebuild_kdump_initrd fi + # delete tmp conf folder for dracut + rm -rf /tmp/kdumpctl.dracut.conf + return $? } -- 2.9.3

2 2

[PATCH v2] kdumpctl: eliminate redundant lsinitrd in dracut
by Ziyue Yang 09 May '17

09 May '17

1 0

[PATCH v2] kdumpctl: eliminate redundant lsinitrd in dracut
by Ziyue Yang 09 May '17

09 May '17

Currently in Fedora/RedHat dracut installs its fedora.conf.example as the default config file, in which sysloglvl is set 5. This leads to maxloglvl=5 in dracut calls, making unnecessary lsinitrd calls during initramfs builds. This patch makes use of --conf and --confdir arguments of dracut, creates temp config directory before mkdumprd(dracut) calls. It appends sysloglvl=0 option by creating a 99-kdumpctl.conf file in the temp config directory. 1) Before this patch $ kdumpctl stop; touch /etc/kdump.conf; time kdumpctl start kexec: unloaded kdump kernel Stopping kdump: [OK] Detected change(s) in the following file(s): /etc/kdump.conf Rebuilding /boot/initramfs-4.10.10-200.fc25.x86_64kdump.img 4.10.10-200.fc25_x86_64 kexec: loaded kdump kernel Starting kdump: [OK] real 0m18.716s user 0m13.863s sys 0m3.269s 2) After this patch $ kdumpctl stop; touch /etc/kdump.conf; time kdumpctl start kexec: unloaded kdump kernel Stopping kdump: [OK] Detected change(s) in the following file(s): /etc/kdump.conf Rebuilding /boot/initramfs-4.10.10-200.fc25.x86_64kdump.img 4.10.10-200.fc25_x86_64 kexec: loaded kdump kernel Starting kdump: [OK] real 0m13.665s user 0m10.945s sys 0m2.907s Signed-off-by: Ziyue Yang <ziyang(a)redhat.com> --- kdumpctl | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/kdumpctl b/kdumpctl index 4d6b3e8..defd57e 100755 --- a/kdumpctl +++ b/kdumpctl @@ -5,7 +5,6 @@ KDUMP_KERNELVER="" KDUMP_COMMANDLINE="" KEXEC_ARGS="" KDUMP_CONFIG_FILE="/etc/kdump.conf" -MKDUMPRD="/sbin/mkdumprd -f" SAVE_PATH=/var/crash SSH_KEY_LOCATION="/root/.ssh/kdump_id_rsa" INITRD_CHECKSUM_LOCATION="/boot/.fadump_initrd_checksum" @@ -20,6 +19,18 @@ DEFAULT_DUMP_MODE="kdump" image_time=0 [[ $dracutbasedir ]] || dracutbasedir=/usr/lib/dracut + +# lower dracut's default sysloglvl to speedup initramfs build +DRACUT_SYSLOGLVL="2" +# make temp dir for dracut conf files +[[ $dracutconfdir ]] || dracutconfdir=/tmp/kdumpctl.dracut.conf +mkdir -p $dracutconfdir/dracut.conf.d +[[ -e $dracutbasedir/dracut.conf.d ]] && cp -rf $dracutbasedir/dracut.conf.d $dracutconfdir/ +[[ -e $dracutbasedir/dracut.conf ]] && cp -rf $dracutbasedir/dracut.conf $dracutconfdir/ +echo "sysloglvl=$DRACUT_SYSLOGLVL" > $dracutconfdir/dracut.conf.d/99-kdumpctl.conf + +MKDUMPRD="/sbin/mkdumprd --conf $dracutconfdir/dracut.conf --confdir $dracutconfdir/dracut.conf.d -f" + . $dracutbasedir/dracut-functions.sh . /lib/kdump/kdump-lib.sh @@ -284,6 +295,9 @@ rebuild_initrd() rebuild_kdump_initrd fi + # delete tmp conf folder for dracut + rm -rf /tmp/kdumpctl.dracut.conf + return $? } -- 2.9.3

1 0

[PATCH] kdumpctl: eliminate redundant lsinitrd in dracut
by Ziyue Yang 09 May '17

09 May '17

Currently in Fedora/RedHat dracut installs its fedora.conf.example as the default config file, in which sysloglvl is set 5. This leads to maxloglvl=5 in dracut calls, making unnecessary lsinitrd calls during initramfs builds. This patch makes use of --conf and --confdir arguments of dracut, creates temp config directory before mkdumprd(dracut) calls. It appends sysloglvl=0 option by creating a 99-kdumpctl.conf file in the temp config directory. 1) Before this patch $ kdumpctl stop; touch /etc/kdump.conf; time kdumpctl start kexec: unloaded kdump kernel Stopping kdump: [OK] Detected change(s) in the following file(s): /etc/kdump.conf Rebuilding /boot/initramfs-4.10.10-200.fc25.x86_64kdump.img 4.10.10-200.fc25_x86_64 kexec: loaded kdump kernel Starting kdump: [OK] real 0m18.716s user 0m13.863s sys 0m3.269s 2) After this patch $ kdumpctl stop; touch /etc/kdump.conf; time kdumpctl start kexec: unloaded kdump kernel Stopping kdump: [OK] Detected change(s) in the following file(s): /etc/kdump.conf Rebuilding /boot/initramfs-4.10.10-200.fc25.x86_64kdump.img 4.10.10-200.fc25_x86_64 kexec: loaded kdump kernel Starting kdump: [OK] real 0m13.665s user 0m10.945s sys 0m2.907s Signed-off-by: Ziyue Yang <ziyang(a)redhat.com> --- kdumpctl | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/kdumpctl b/kdumpctl index 4d6b3e8..0612294 100755 --- a/kdumpctl +++ b/kdumpctl @@ -5,7 +5,6 @@ KDUMP_KERNELVER="" KDUMP_COMMANDLINE="" KEXEC_ARGS="" KDUMP_CONFIG_FILE="/etc/kdump.conf" -MKDUMPRD="/sbin/mkdumprd -f" SAVE_PATH=/var/crash SSH_KEY_LOCATION="/root/.ssh/kdump_id_rsa" INITRD_CHECKSUM_LOCATION="/boot/.fadump_initrd_checksum" @@ -20,6 +19,18 @@ DEFAULT_DUMP_MODE="kdump" image_time=0 [[ $dracutbasedir ]] || dracutbasedir=/usr/lib/dracut + +# lower dracut's default sysloglvl to speedup initramfs build +DRACUT_SYSLOGLVL="0" +# make temp dir for dracut conf files +[[ $dracutconfdir ]] || dracutconfdir=/tmp/kdumpctl.dracut.conf +mkdir -p $dracutconfdir/dracut.conf.d +[[ -e $dracutbasedir/dracut.conf.d ]] && cp -rf $dracutbasedir/dracut.conf.d $dracutconfdir/ +[[ -e $dracutbasedir/dracut.conf ]] && cp -rf $dracutbasedir/dracut.conf $dracutconfdir/ +echo "sysloglvl=$DRACUT_SYSLOGLVL" > $dracutconfdir/dracut.conf.d/99-kdumpctl.conf + +MKDUMPRD="/sbin/mkdumprd --conf $dracutconfdir/dracut.conf --confdir $dracutconfdir/dracut.conf.d -f" + . $dracutbasedir/dracut-functions.sh . /lib/kdump/kdump-lib.sh @@ -284,6 +295,9 @@ rebuild_initrd() rebuild_kdump_initrd fi + # delete tmp conf folder for dracut + rm -rf /tmp/kdumpctl.dracut.conf + return $? } -- 2.9.3

2 2

[PATCH] kdumpctl: for fence_kdump, the ipaddr of this node should be excluded from list
by Pingfan Liu 09 May '17

09 May '17

Since user can use ipaddr of a node instead of its hostname, so we need to protect from this case. Signed-off-by: Pingfan Liu <piliu(a)redhat.com> --- kdump.conf | 4 ++-- kdumpctl | 7 +++++++ 2 files changed, 9 insertions(+), 2 deletions(-) diff --git a/kdump.conf b/kdump.conf index 1e24e1b..cfdaec7 100644 --- a/kdump.conf +++ b/kdump.conf @@ -137,8 +137,8 @@ # # fence_kdump_nodes <node(s)> # - List of cluster node(s), separated by spaces, to send -# fence_kdump notifications to (this option is mandatory to -# enable fence_kdump). +# fence_kdump notifications to. The list should exclude this node itself! +# (this option is mandatory to enable fence_kdump). # #raw /dev/vg/lv_kdump diff --git a/kdumpctl b/kdumpctl index d43f46b..638c6b6 100755 --- a/kdumpctl +++ b/kdumpctl @@ -1118,6 +1118,7 @@ check_kdump_feasibility() check_fence_kdump_config() { local hostname=`hostname` + local ipaddrs=`hostname -i` local nodes=$(get_option_value "fence_kdump_nodes") for node in $nodes; do @@ -1125,6 +1126,12 @@ check_fence_kdump_config() echo "Option fence_kdump_nodes cannot contain $hostname" return 1 fi + # node can be ipaddr + echo $ipaddrs | grep $node + if [ $? -eq 0 ]; then + echo "Option fence_kdump_nodes cannot contain $node" + return 1 + fi done return 0 -- 2.7.4

1 0

[PATCH v3 0/4] optimize kdump service start time in case of no initramfs rebuild
by Xunlei Pang 05 May '17

05 May '17

kdump service takes a few seconds to start even no need to rebuild initramfs, which is a little longer compared to other systemd services, it may affects the system boot time a little, we better optimize it as possible as we can. The main root cause of this is the use of "lsinitrd" which is time-consuming. This series is mainly reducing the "lsinitrd" uses. The time data in this series is on Intel(R) Core(TM) i7-5600U CPU @ 2.60GHz. After this series, kdump service start time in case of no initramfs rebuild is 1s~2s, it should be good enough considering the service is indeed running parallelly with others. Before this patchset: $ time kdumpctl start kexec: loaded kdump kernel Starting kdump: [OK] real 0m5.156s user 0m5.169s sys 0m1.269s After this patchset: $ time kdumpctl start kexec: loaded kdump kernel Starting kdump: [OK] real 0m1.151s user 0m1.028s sys 0m0.300s There are still two lsinitrd operations(each consumes around 0.35s) remaining, we can reconsider it if there are still complaints in the future. Xunlei Pang (4): kdumpctl: remove is_mode_switched() kdumpctl: improve check_wdt_modified() kdumpctl: update check_dump_fs_modified() to use "lsinitrd -f" kdumpctl: improve "while read" time for /etc/kdump.conf kdumpctl | 115 +++++++++++++++++++++++++++++++-------------------------------- 1 file changed, 57 insertions(+), 58 deletions(-) -- 1.8.3.1

3 7

[PATCH v2 0/3] optimize kdump service start time in case of no initramfs rebuild
by Xunlei Pang 04 May '17

04 May '17

kdump service takes a few seconds to start even no need to rebuild initramfs, which is a little longer compared to other systemd services, it may affects the system boot time a little, we better optimize it as possible as we can. The main root cause of this is the use of "lsinitrd" which is time-consuming. This series is actually reducing the "lsinitrd" uses. Tested on Intel(R) Core(TM) i7-5600U CPU @ 2.60GHz. Before this patchset: $ time kdumpctl start kexec: loaded kdump kernel Starting kdump: [OK] real 0m5.156s user 0m5.169s sys 0m1.269s After this patchset: $ time kdumpctl start (when kdump lsinitrd tmp file exists) kexec: loaded kdump kernel Starting kdump: [OK] real 0m0.854s user 0m0.389s sys 0m0.582s Xunlei Pang (3): kdumpctl: remove is_mode_switched() kdumpctl: improve check_wdt_modified() introduce kdump lsinitrd support dracut-module-setup.sh | 5 +++ kdump-lib.sh | 26 +++++++++++++++ kdumpctl | 88 +++++++++++++++++++++++--------------------------- mkdumprd | 7 ++++ 4 files changed, 78 insertions(+), 48 deletions(-) -- 1.8.3.1

3 7

[PATCH v2 4/3] kdumpctl: improve "while read" time for /etc/kdump.conf
by Xunlei Pang 03 May '17

03 May '17

I found using "cat $KDUMP_CONFIG_FILE|grep -v "^#"|while read ..." instead of "while read ... do ...; done < $KDUMP_CONFIG_FILE" will make the script run faster. (in case of no initramfs rebuild) Before this patchset: $ time kdumpctl start kexec: loaded kdump kernel Starting kdump: [OK] real 0m0.854s user 0m0.389s sys 0m0.582s After this patchset: $ time kdumpctl start kexec: loaded kdump kernel Starting kdump: [OK] real 0m0.465s user 0m0.305s sys 0m0.194s Now most of start time is consumed by kexec syscall(around 0.330s) which is impossible for us to optimize from kdump side. Signed-off-by: Xunlei Pang <xlpang(a)redhat.com> --- Please append to "[PATCH v2 0/3] optimize kdump service start time in case of no initramfs rebuild". kdumpctl | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/kdumpctl b/kdumpctl index 11d7f1f..d075a1a 100755 --- a/kdumpctl +++ b/kdumpctl @@ -365,7 +365,7 @@ check_config() return 1 } - while read config_opt config_val; do + cat $KDUMP_CONFIG_FILE | grep -v "^#" | while read config_opt config_val; do # remove inline comments after the end of a directive. config_val=$(strip_comments $config_val) case "$config_opt" in @@ -386,7 +386,7 @@ check_config() return 1; ;; esac - done < $KDUMP_CONFIG_FILE + done check_default_config || return 1 @@ -792,7 +792,7 @@ load_kdump() check_ssh_config() { - while read config_opt config_val; do + cat $KDUMP_CONFIG_FILE | grep -v "^#" | while read config_opt config_val; do # remove inline comments after the end of a directive. config_val=$(strip_comments $config_val) case "$config_opt" in @@ -813,7 +813,7 @@ check_ssh_config() *) ;; esac - done < $KDUMP_CONFIG_FILE + done #make sure they've configured kdump.conf for ssh dumps local SSH_TARGET=`echo -n $DUMP_TARGET | sed -n '/.*@/p'` -- 1.8.3.1

1 0

[PATCH 0/4] optimize kdump service start time in case of no initramfs rebuild
by Xunlei Pang 02 May '17

02 May '17

kdump service takes a few seconds to start even no need to rebuild initramfs, which is a little longer compared to other systemd services, it may affects the system boot time a little, we better optimize it as possible as we can. Before this patchset: $ time kdumpctl start kexec: loaded kdump kernel Starting kdump: [OK] real 0m5.156s user 0m5.169s sys 0m1.269s After this patchset: $ time kdumpctl start (when kdump lsinitrd tmp file exists) kexec: loaded kdump kernel Starting kdump: [OK] real 0m0.854s user 0m0.389s sys 0m0.582s Xunlei Pang (4): kdumpctl: remove is_mode_switched() kdumpctl: improve check_wdt_modified() kdumpctl: update check_dump_fs_modified() to use "lsinitrd -f" introduce kdump lsinitrd support dracut-module-setup.sh | 5 +++ kdump-lib.sh | 26 ++++++++++++ kdumpctl | 107 ++++++++++++++++++++++++------------------------- mkdumprd | 6 +++ 4 files changed, 90 insertions(+), 54 deletions(-) -- 1.8.3.1

5 16

[PATCH] kdumpctl: bail out earlier in case of no reserved memory
by Xunlei Pang 02 May '17

02 May '17

Some cloud people complained that VM boot speed is slower than Ubuntu and other distributions, after some debugging, we found that one of the causes is kdump service starts too slow(7seconds according to the test result on the test VM), actually there is no "crashkernel=X" specified. Although kdump service is parallel, it affects the speed more or less especially on VMs with few cpus, which is unacceptable. It is even worse when kdump initramfs is built out in case of no reserved memory at first boot. Commit afa4a35d3 ("kdumpctrl: kdump feasibility should fail if no crash memory") can actually solve this issue. This patch is a supplement of above-mentioned commit, we bail out start() even earlier in case of no reserved memory. Also made some cosmatic changes for check_crash_mem_reserved(). 1) Before this patch $ time kdumpctl start No memory reserved for crash kernel. Starting kdump: [FAILED] real 0m0.282s user 0m0.184s sys 0m0.146s 2) After this patch $ time kdumpctl start No memory reserved for crash kernel Starting kdump: [FAILED] real 0m0.010s user 0m0.008s sys 0m0.001s Signed-off-by: Xunlei Pang <xlpang(a)redhat.com> --- kdumpctl | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-) diff --git a/kdumpctl b/kdumpctl index 6b5be09..129cb6a 100755 --- a/kdumpctl +++ b/kdumpctl @@ -1074,10 +1074,11 @@ is_secure_boot_enforced() check_crash_mem_reserved() { - MEM_RESERVED=$(cat /sys/kernel/kexec_crash_size) - if [ $MEM_RESERVED -eq 0 ] - then - echo "No memory reserved for crash kernel." >&2 + local mem_reserved + + mem_reserved=$(cat /sys/kernel/kexec_crash_size) + if [ $mem_reserved -eq 0 ]; then + echo "No memory reserved for crash kernel" return 1 fi @@ -1163,22 +1164,23 @@ check_default_config() start() { - check_config + check_dump_feasibility if [ $? -ne 0 ]; then echo "Starting kdump: [FAILED]" return 1 fi - if sestatus 2>/dev/null | grep -q "SELinux status.*enabled"; then - selinux_relabel - fi - save_raw + check_config if [ $? -ne 0 ]; then echo "Starting kdump: [FAILED]" return 1 fi - check_dump_feasibility + if sestatus 2>/dev/null | grep -q "SELinux status.*enabled"; then + selinux_relabel + fi + + save_raw if [ $? -ne 0 ]; then echo "Starting kdump: [FAILED]" return 1 -- 1.8.3.1

4 6

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

kexec May 2017