Re: [PATCH V3] Disable transparent hugepages in second kernel

Transparent hugepages are on by default. Disable it in kdump kernel by adding the parameter 'transparent_hugepage=never'. This might help us with some of the memory issues we are facing. From my test on two arch, not only there are no any bad effect on saving vmcore after turn off THP, but also we can get more 'MemAvailable:' in the kdump kernel.

1)x86_64 without the parameter ===================== kdump:/# cat /proc/cmdline BOOT_IMAGE=/vmlinuz-3.10.0-229.el7.x86_64 root=/dev/mapper/rhel_ibm--x3250m4--01-root ro rd.lvm.lv=rhel_ibm-x3250m4-01/swap console=ttyS0,115200n8 rd.lvm.lv=rhel_ibm-x3250m4-01/root LANG=en_US.UTF-8 irqpoll nr_cpus=1 reset_devices cgroup_disable=memory mce=off numa=off udev.children-max=2 panic=10 rootflags=nofail acpi_no_memhotplug disable_cpu_apicid=0 elfcorehdr=869764K kdump:/# cat /proc/meminfo MemTotal: 145492 kB MemFree: 68284 kB MemAvailable: 111632 kB <<------ Buffers: 36 kB Cached: 48184 kB ... added the parameter ===================== kdump:/# cat /proc/cmdline BOOT_IMAGE=/vmlinuz-3.10.0-229.el7.x86_64 root=/dev/mapper/rhel_ibm--x3250m4--01-root ro rd.lvm.lv=rhel_ibm-x3250m4-01/swap console=ttyS0,115200n8 rd.lvm.lv=rhel_ibm-x3250m4-01/root LANG=en_US.UTF-8 irqpoll nr_cpus=1 reset_devices cgroup_disable=memory mce=off numa=off udev.children-max=2 panic=10 rootflags=nofail acpi_no_memhotplug transparent_hugepage=never disable_cpu_apicid=0 elfcorehdr=869764K kdump:/# cat /proc/meminfo MemTotal: 145492 kB MemFree: 68388 kB MemAvailable: 111728 kB <<------- ... VmallocChunk: 34359659520 kB HardwareCorrupted: 0 kB AnonHugePages: 0 kB ... 2)ppc64 without the parameter ==================== kdump:/# cat /proc/cmdline BOOT_IMAGE=/vmlinuz-3.10.0-229.el7.ppc64 root=/dev/mapper/rhel_ibm--p8--05--lp6-root ro rd.lvm.lv=rhel_ibm-p8-05-lp6/root rd.lvm.lv=rhel_ibm-p8-05-lp6/swap LANG=en_US.UTF-8 irqpoll maxcpus=1 noirqdistrib reset_devices cgroup_disable=memory numa=off udev.children-max=2 ehea.use_mcs=0 panic=10 rootflags=nofail kvm_cma_resv_ratio=0 elfcorehdr=154880K kdump:/# cat /proc/meminfo MemTotal: 480832 kB MemFree: 293952 kB MemAvailable: 427840 kB <<-------- mallocUsed: 23680 kB VmallocChunk: 8589901824 kB HardwareCorrupted: 0 kB AnonHugePages: 0 kB ... added the parameter =================== kdump:/# cat /proc/cmdline BOOT_IMAGE=/vmlinuz-3.10.0-229.el7.ppc64 root=/dev/mapper/rhel_ibm--p8--05--lp6-root ro rd.lvm.lv=rhel_ibm-p8-05-lp6/root rd.lvm.lv=rhel_ibm-p8-05-lp6/swap LANG=en_US.UTF-8 irqpoll maxcpus=1 noirqdistrib reset_devices cgroup_disable=memory numa=off udev.children-max=2 ehea.use_mcs=0 panic=10 rootflags=nofail kvm_cma_resv_ratio=0 transparent_hugepage=never elfcorehdr=154880K kdump:/# cat /proc/meminfo MemTotal: 480832 kB MemFree: 294592 kB MemAvailable: 428480 kB <<------- ... HugePages_Total: 0 Signed-off-by: Li Wang <liwang(a)redhat.com&gt; --- kdump.sysconfig.i386 | 2 +- kdump.sysconfig.ppc64 | 2 +- kdump.sysconfig.ppc64le | 2 +- kdump.sysconfig.s390x | 2 +- kdump.sysconfig.x86_64 | 2 +- 5 files changed, 5 insertions(+), 5 deletions(-) diff --git a/kdump.sysconfig.i386 b/kdump.sysconfig.i386 index 84b2447..bb7a6e5 100644 --- a/kdump.sysconfig.i386 +++ b/kdump.sysconfig.i386 @@ -16,7 +16,7 @@ KDUMP_COMMANDLINE="" # This variable lets us append arguments to the current kdump commandline # As taken from either KDUMP_COMMANDLINE above, or from /proc/cmdline -KDUMP_COMMANDLINE_APPEND="irqpoll nr_cpus=1 reset_devices numa=off udev.children-max=2 panic=10 rootflags=nofail" +KDUMP_COMMANDLINE_APPEND="irqpoll nr_cpus=1 reset_devices numa=off udev.children-max=2 panic=10 rootflags=nofail transparent_hugepage=never" # Any additional kexec arguments required. In most situations, this should # be left empty diff --git a/kdump.sysconfig.ppc64 b/kdump.sysconfig.ppc64 index 5295626..dd09598 100644 --- a/kdump.sysconfig.ppc64 +++ b/kdump.sysconfig.ppc64 @@ -16,7 +16,7 @@ KDUMP_COMMANDLINE="" # This variable lets us append arguments to the current kdump commandline # As taken from either KDUMP_COMMANDLINE above, or from /proc/cmdline -KDUMP_COMMANDLINE_APPEND="irqpoll maxcpus=1 noirqdistrib reset_devices cgroup_disable=memory numa=off udev.children-max=2 ehea.use_mcs=0 panic=10 rootflags=nofail kvm_cma_resv_ratio=0" +KDUMP_COMMANDLINE_APPEND="irqpoll maxcpus=1 noirqdistrib reset_devices cgroup_disable=memory numa=off udev.children-max=2 ehea.use_mcs=0 panic=10 rootflags=nofail kvm_cma_resv_ratio=0 transparent_hugepage=never" # Any additional kexec arguments required. In most situations, this should # be left empty diff --git a/kdump.sysconfig.ppc64le b/kdump.sysconfig.ppc64le index 5295626..dd09598 100644 --- a/kdump.sysconfig.ppc64le +++ b/kdump.sysconfig.ppc64le @@ -16,7 +16,7 @@ KDUMP_COMMANDLINE="" # This variable lets us append arguments to the current kdump commandline # As taken from either KDUMP_COMMANDLINE above, or from /proc/cmdline -KDUMP_COMMANDLINE_APPEND="irqpoll maxcpus=1 noirqdistrib reset_devices cgroup_disable=memory numa=off udev.children-max=2 ehea.use_mcs=0 panic=10 rootflags=nofail kvm_cma_resv_ratio=0" +KDUMP_COMMANDLINE_APPEND="irqpoll maxcpus=1 noirqdistrib reset_devices cgroup_disable=memory numa=off udev.children-max=2 ehea.use_mcs=0 panic=10 rootflags=nofail kvm_cma_resv_ratio=0 transparent_hugepage=never" # Any additional kexec arguments required. In most situations, this should # be left empty diff --git a/kdump.sysconfig.s390x b/kdump.sysconfig.s390x index 745dd27..b103a88 100644 --- a/kdump.sysconfig.s390x +++ b/kdump.sysconfig.s390x @@ -16,7 +16,7 @@ KDUMP_COMMANDLINE="" # This variable lets us append arguments to the current kdump commandline # As taken from either KDUMP_COMMANDLINE above, or from /proc/cmdline -KDUMP_COMMANDLINE_APPEND="nr_cpus=1 cgroup_disable=memory numa=off udev.children-max=2 panic=10 rootflags=nofail" +KDUMP_COMMANDLINE_APPEND="nr_cpus=1 cgroup_disable=memory numa=off udev.children-max=2 panic=10 rootflags=nofail transparent_hugepage=never" # Any additional /sbin/mkdumprd arguments required. MKDUMPRD_ARGS="" diff --git a/kdump.sysconfig.x86_64 b/kdump.sysconfig.x86_64 index d9ad9b5..7991d68 100644 --- a/kdump.sysconfig.x86_64 +++ b/kdump.sysconfig.x86_64 @@ -16,7 +16,7 @@ KDUMP_COMMANDLINE="" # This variable lets us append arguments to the current kdump commandline # As taken from either KDUMP_COMMANDLINE above, or from /proc/cmdline -KDUMP_COMMANDLINE_APPEND="irqpoll nr_cpus=1 reset_devices cgroup_disable=memory mce=off numa=off udev.children-max=2 panic=10 rootflags=nofail acpi_no_memhotplug" +KDUMP_COMMANDLINE_APPEND="irqpoll nr_cpus=1 reset_devices cgroup_disable=memory mce=off numa=off udev.children-max=2 panic=10 rootflags=nofail acpi_no_memhotplug transparent_hugepage=never" # Any additional kexec arguments required. In most situations, this should # be left empty -- 1.8.3.1 _______________________________________________ kexec mailing list kexec(a)lists.fedoraproject.org https://lists.fedoraproject.org/mailman/listinfo/kexec