On 04/03/19 at 10:58am, Pingfan Liu wrote:
> On Tue, Apr 2, 2019 at 4:08 PM Baoquan He <b...@redhat.com> wrote:
> >
> > > +/* handle crashkernel=x@y or =range1:size1[,range2:size2,...]@offset
> > > options */
> > > +static void mem_avoid_specified_crashkernel_region(char *option)
> > > +{
> > > + unsigned long long crash_size, crash_base = 0;
> > > + char *first_colon, *first_space, *cur = option;
> > > +
> >
> > Another thing which need be noticed is that you may only need to handle
> > when '@' is found. Otherwise just let it go. Right?
> >
> According to kernel's behavior, only the last "crashkernel=" option
> takes effect. Hence if no '@', then clearing mem_avoid
Here I mean that you can search '@' at the beginning if crashkernel is
found. Maybe no need to clear mem_avoid since it's global data, has been
initialized to 0 during loading. It's in BSS, right?
You don't have to search first colon or first space, then parse size of
crashkernel, and finally find out that it's only
crashkernel=512M-2G:64M,2G-:128M
style, no '@' specified. What do you think?
>
> > > + first_colon = strchr(option, ':');
> > > + first_space = strchr(option, ' ');
> > > + /* if contain ":" */
> > > + if (first_colon && (!first_space || first_colon < first_space)) {
> > > + int i;
> > > + u64 total_sz = 0;
> > > + struct boot_e820_entry *entry;
> > > +
> > > + for (i = 0; i < boot_params->e820_entries; i++) {
> > > + entry = &boot_params->e820_table[i];
> > > + /* Skip non-RAM entries. */
> > > + if (entry->type != E820_TYPE_RAM)
> > > + continue;
> > > + total_sz += entry->size;
> > > + }
> > > + handle_crashkernel_mem(option, total_sz, &crash_size,
> > > + &crash_base);
> > > + } else {
> > > + crash_size = memparse(option, &cur);
> > > + if (option == cur)
> > > + return;
> > > + while (*cur && *cur != ' ' && *cur != '@')
> > > + cur++;
> > > + if (*cur == '@') {
> > > + option = cur + 1;
> > > + crash_base = memparse(option, &cur);
> > > + }
> > > + }
> > > + if (crash_base) {
> > > + mem_avoid[MEM_AVOID_CRASHKERNEL].start = crash_base;
> > > + mem_avoid[MEM_AVOID_CRASHKERNEL].size = crash_size;
> > > + } else {
> > > + /*
> > > + * Clearing mem_avoid if no offset is given. This is
> > > consistent
> > > + * with kernel, which uses the last crashkernel= option.
> > > + */
> > > + mem_avoid[MEM_AVOID_CRASHKERNEL].start = 0;
> > > + mem_avoid[MEM_AVOID_CRASHKERNEL].size = 0;
> > > + }
> > > +}
