Re: [PATCH v5 2/8] x86/crash hp: Introduce CRASH_HOTPLUG configuration options
On 3/21/22 06:59, Baoquan He wrote: On 03/03/22 at 11:27am, Eric DeVolder wrote: Support for CPU and memory hotplug for crash is controlled by the CRASH_HOTPLUG configuration option, introduced by this patch. The CRASH_HOTPLUG_ELFCOREHDR_SZ related configuration option is also introduced with this patch. Maybe can rephrase it as: x86/crash: Introduce new options to support cpu and memory hotplug of crash CRASH_HOTPLUG is to enable cpu and memory hotplug of crash. CRASH_HOTPLUG_ELFCOREHDR_SZ is used to Specify the maximum size of the elfcorehdr buffer/segment. This is a preparation for later usage. Otherwise, this looks good to me. Commit message updated. eric Signed-off-by: Eric DeVolder --- arch/x86/Kconfig | 26 ++ 1 file changed, 26 insertions(+) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 9f5bd41bf660..37eb26563f07 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -2061,6 +2061,32 @@ config CRASH_DUMP (CONFIG_RELOCATABLE=y). For more details see Documentation/admin-guide/kdump/kdump.rst +config CRASH_HOTPLUG + bool "kernel updates of crash elfcorehdr" + depends on CRASH_DUMP && (HOTPLUG_CPU || MEMORY_HOTPLUG) && KEXEC_FILE + help + Enable the kernel to update the crash elfcorehdr (which contains + the list of CPUs and memory regions) directly when hot plug/unplug + of CPUs or memory. Otherwise userspace must monitor these hot + plug/unplug change notifications via udev in order to + unload-then-reload the crash kernel so that the list of CPUs and + memory regions is kept up-to-date. Note that the udev CPU and + memory change notifications still occur (however, userspace is not + required to monitor for crash dump purposes). + +config CRASH_HOTPLUG_ELFCOREHDR_SZ + depends on CRASH_HOTPLUG + int + default 131072 + help + Specify the maximum size of the elfcorehdr buffer/segment. + The 128KiB default is sized so that it can accommodate 2048 + Elf64_Phdr, where each Phdr represents either a CPU or a + region of memory. + For example, this size can accommodate a machine with up to 1024 + CPUs and up to 1024 memory regions, eg. as represented by the + 'System RAM' entries in /proc/iomem. + config KEXEC_JUMP bool "kexec jump" depends on KEXEC && HIBERNATION -- 2.27.0 ___ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec
Re: [PATCH v5 2/8] x86/crash hp: Introduce CRASH_HOTPLUG configuration options
On 03/03/22 at 11:27am, Eric DeVolder wrote: > Support for CPU and memory hotplug for crash is controlled by the > CRASH_HOTPLUG configuration option, introduced by this patch. > > The CRASH_HOTPLUG_ELFCOREHDR_SZ related configuration option is > also introduced with this patch. Maybe can rephrase it as: x86/crash: Introduce new options to support cpu and memory hotplug of crash CRASH_HOTPLUG is to enable cpu and memory hotplug of crash. CRASH_HOTPLUG_ELFCOREHDR_SZ is used to Specify the maximum size of the elfcorehdr buffer/segment. This is a preparation for later usage. Otherwise, this looks good to me. > > Signed-off-by: Eric DeVolder > --- > arch/x86/Kconfig | 26 ++ > 1 file changed, 26 insertions(+) > > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig > index 9f5bd41bf660..37eb26563f07 100644 > --- a/arch/x86/Kconfig > +++ b/arch/x86/Kconfig > @@ -2061,6 +2061,32 @@ config CRASH_DUMP > (CONFIG_RELOCATABLE=y). > For more details see Documentation/admin-guide/kdump/kdump.rst > > +config CRASH_HOTPLUG > + bool "kernel updates of crash elfcorehdr" > + depends on CRASH_DUMP && (HOTPLUG_CPU || MEMORY_HOTPLUG) && KEXEC_FILE > + help > + Enable the kernel to update the crash elfcorehdr (which contains > + the list of CPUs and memory regions) directly when hot plug/unplug > + of CPUs or memory. Otherwise userspace must monitor these hot > + plug/unplug change notifications via udev in order to > + unload-then-reload the crash kernel so that the list of CPUs and > + memory regions is kept up-to-date. Note that the udev CPU and > + memory change notifications still occur (however, userspace is not > + required to monitor for crash dump purposes). > + > +config CRASH_HOTPLUG_ELFCOREHDR_SZ > + depends on CRASH_HOTPLUG > + int > + default 131072 > + help > + Specify the maximum size of the elfcorehdr buffer/segment. > + The 128KiB default is sized so that it can accommodate 2048 > + Elf64_Phdr, where each Phdr represents either a CPU or a > + region of memory. > + For example, this size can accommodate a machine with up to 1024 > + CPUs and up to 1024 memory regions, eg. as represented by the > + 'System RAM' entries in /proc/iomem. > + > config KEXEC_JUMP > bool "kexec jump" > depends on KEXEC && HIBERNATION > -- > 2.27.0 > ___ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec
[PATCH v5 2/8] x86/crash hp: Introduce CRASH_HOTPLUG configuration options
Support for CPU and memory hotplug for crash is controlled by the CRASH_HOTPLUG configuration option, introduced by this patch. The CRASH_HOTPLUG_ELFCOREHDR_SZ related configuration option is also introduced with this patch. Signed-off-by: Eric DeVolder --- arch/x86/Kconfig | 26 ++ 1 file changed, 26 insertions(+) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 9f5bd41bf660..37eb26563f07 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -2061,6 +2061,32 @@ config CRASH_DUMP (CONFIG_RELOCATABLE=y). For more details see Documentation/admin-guide/kdump/kdump.rst +config CRASH_HOTPLUG + bool "kernel updates of crash elfcorehdr" + depends on CRASH_DUMP && (HOTPLUG_CPU || MEMORY_HOTPLUG) && KEXEC_FILE + help + Enable the kernel to update the crash elfcorehdr (which contains + the list of CPUs and memory regions) directly when hot plug/unplug + of CPUs or memory. Otherwise userspace must monitor these hot + plug/unplug change notifications via udev in order to + unload-then-reload the crash kernel so that the list of CPUs and + memory regions is kept up-to-date. Note that the udev CPU and + memory change notifications still occur (however, userspace is not + required to monitor for crash dump purposes). + +config CRASH_HOTPLUG_ELFCOREHDR_SZ + depends on CRASH_HOTPLUG + int + default 131072 + help + Specify the maximum size of the elfcorehdr buffer/segment. + The 128KiB default is sized so that it can accommodate 2048 + Elf64_Phdr, where each Phdr represents either a CPU or a + region of memory. + For example, this size can accommodate a machine with up to 1024 + CPUs and up to 1024 memory regions, eg. as represented by the + 'System RAM' entries in /proc/iomem. + config KEXEC_JUMP bool "kexec jump" depends on KEXEC && HIBERNATION -- 2.27.0 ___ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec
