Re: [PATCH v3 1/5] crash: move crashkernel parsing and vmcore related code under CONFIG_CRASH_CORE

[Hari Bathini]

Hi Dave,


On Thursday 05 January 2017 11:47 AM, Dave Young wrote:
> Hi, Hari
>
> On 01/02/17 at 07:43pm, Hari Bathini wrote:
> > Traditionally, kdump is used to save vmcore in case of a crash. Some
> > architectures like powerpc can save vmcore using architecture specific
> > support instead of kexec/kdump mechanism. Such architecture specific
> > support also needs to reserve memory, to be used by dump capture kernel.
> > crashkernel parameter can be a reused, for memory reservation, by such
> > architecture specific infrastructure.
> >
> > But currently, code related to vmcoreinfo and parsing of crashkernel
> > parameter is built under CONFIG_KEXEC_CORE. This patch introduces
> > CONFIG_CRASH_CORE and moves the above mentioned code under this config,
> > allowing code reuse without dependency on CONFIG_KEXEC. There is no
> > functional change with this patch.
> >
> > Signed-off-by: Hari Bathini <hbathini@xxxxxxxxxxxxxxxxxx>
> > ---
> >
> > Changes from v2:
> > * Used CONFIG_CRASH_CORE instead of CONFIG_KEXEC_CORE at
> >    appropriate places in printk and ksysfs.
> >
> >
> >   arch/Kconfig               |    4
> >   include/linux/crash_core.h |   65 ++++++
> >   include/linux/kexec.h      |   57 ------
> >   include/linux/printk.h     |    4
> >   kernel/Makefile            |    1
> >   kernel/crash_core.c        |  445 ++++++++++++++++++++++++++++++++++++++++++++
> >   kernel/kexec_core.c        |  404 ----------------------------------------
> >   kernel/ksysfs.c            |    8 +
> >   kernel/printk/printk.c     |    6 -
> >   9 files changed, 531 insertions(+), 463 deletions(-)
> >   create mode 100644 include/linux/crash_core.h
> >   create mode 100644 kernel/crash_core.c
> [snip]
>
> >   #ifndef CONFIG_TINY_RCU
> > diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
> > index 8b26964..d0dfebd 100644
> > --- a/kernel/printk/printk.c
> > +++ b/kernel/printk/printk.c
> > @@ -32,7 +32,7 @@
> >   #include <linux/bootmem.h>
> >   #include <linux/memblock.h>
> >   #include <linux/syscalls.h>
> > -#include <linux/kexec.h>
> > +#include <linux/crash_core.h>
> >   #include <linux/kdb.h>
> >   #include <linux/ratelimit.h>
> >   #include <linux/kmsg_dump.h>
> > @@ -951,7 +951,7 @@ const struct file_operations kmsg_fops = {
> >   	.release = devkmsg_release,
> >   };
> >   
> > -#ifdef CONFIG_KEXEC_CORE
> > +#ifdef CONFIG_CRASH_CORE
> >   /*
> >    * This appends the listed symbols to /proc/vmcore
> >    *
> > @@ -960,7 +960,7 @@ const struct file_operations kmsg_fops = {
> >    * symbols are specifically used so that utilities can access and extract the
> >    * dmesg log from a vmcore file after a crash.
> >    */
> > -void log_buf_kexec_setup(void)
> > +void log_buf_crash_setup(void)
> I can not think of any better name about the CONFIG_CRASH_CORE though I
> feel it is not excellent so personally I can live with it.
>
> But for this function name log_buf_crash_setup is too general, I can not get
> what it is doing from the name, how about change it to log_buf_vmcoreinfo_setup

log_buf_vmcoreinfo_setup is appropriate.  Also dropped hard-coded values
for DIV_ROUND_UP().
Posted v4 with these changes..

Thanks
Hari