On 03/28/14 at 02:13pm, WANG Chao wrote: > On 03/28/14 at 11:24am, Dave Young wrote: > > > > > > +static void exclude_ram(struct memory_range *mr, int *nr_mr) > > > +{ > > > + int ranges, i, j, m; > > > + > > > + ranges = *nr_mr; > > > + for (i = 0, j = 0; i < ranges; i++) { > > > + if (mr[j].type == RANGE_RAM) { > > > + dbgprintf("Remove RAM %016llx-%016llxx: (%d)\n", mr[j].start, mr[j].end, mr[j].type); > > > + for (m = j; m < *nr_mr; m++) > > > + mr[m] = mr[m+1]; > > > + (*nr_mr)--; > > > + } else { > > > + j++; > > > + } > > > + } > > > + > > > + dbgprint_mem_range("After remove RAM", mr, *nr_mr); > > > +} > > > > This is probably not necessary, what I understand you are doing is below: > > > > get_crash_memory_ranges() > > -> collect all SYSTEM_RAM, ACPI, ACPI_NVS ranges, exclude crash reserved ranges. > > -> the system ram ranges are used to create elf header > > -> the ACPI, ACPI_NVS ranges are used by cmdline_add_memmap_acpi etc. > > Yes. > > > > > memmap_p > > -> contains all the crash reserved ranges > > -> to be used by cmdline_add_memmap > > There's no memmap_p. I'll reuse crash_memory_ranges structure to store > crash reserved ranges, ACPI and ACPI_NVS ranges. So after building ELF > headers for 1st kernel memory ranges, all I have to do is exclude the > SYSTEM_RAM and add crash_reserved to crash_memory_ranges. And then > crash_memory_ranges can be used as 2nd kernel memory ranges. How about do nothing and directly use the mem_ranges: * skip RANGE_RAM, only add the range which is not RANGE_RAM * if the range is RANGE_CRASH_KERNEL (introduce a new type?) then use it as SYSTEM_RAM for 2nd kernel. > > > > > The several memory ranges are twisted and somehow the funcions are duplicate. > > These functions look like similar but each does serve for different purpose. > > > > > So how about just keep one memory ranges array which contains all the ranges which > > include system_ram, acpi, acpi_nvs, crash_reserved range. > > > > In the crashdump-elf.c the function for creating elf headers will check the > > range type, it will just skip the range which is not ram. > > We don't build EFL headers for crash_reserved ranges. So we can't store > system ram and crash_reserved together before building EFL header. There's already below code which ignore the ram ranges.. for (i = 0; i < ranges; i++, range++) { if (range->type != RANGE_RAM) continue; Thanks Dave