Re: [PATCH] [ppc] Do not reserve cpu spin-table for crash kernel

["Suzuki K. Poulose" <suzuki@in.ibm.com>]

Simon,

Please let me know your response.

Thanks
Suzuki

On 06/18/2012 11:57 AM, Suzuki K. Poulose wrote:
> On 05/24/2012 11:39 AM, Suzuki K. Poulose wrote:
>> As of now, the kexec reserves the spin-table for all the CPUs
>> on an SMP machine. The spin-table is pointed to by the
>> cpu-release-addr property in the device-tree. Reserving the
>> spin-table in the crash kernel will cause a BUG(), if the table
>> lies outside the memory reserved for the crashkernel.
>>
>> Disable reserving the spin-table regions and use maxcpus=1 to
>> use only the crashing CPU to boot the crash kernel.
>>
>> Signed-off-by: Suzuki K. Poulose<suzuki@in.ibm.com>
>
> Simon,
>
> Any response on this one ?
>
> I have tested this on a Currituck board (476, SMP) with a UP kernel.
> Without this patch, the secondary kernel hits 'PANIC' in boot while
> trying to reserve a memory(the spin table), outside the memory
> range(crash reserve).
>
>
> Thanks
> Suzuki
>
>> ---
>>
>> kexec/arch/ppc/crashdump-powerpc.c | 19 +++++++++++++------
>> kexec/arch/ppc/fixup_dtb.c | 4 ++++
>> 2 files changed, 17 insertions(+), 6 deletions(-)
>>
>> diff --git a/kexec/arch/ppc/crashdump-powerpc.c
>> b/kexec/arch/ppc/crashdump-powerpc.c
>> index 1bef69b..4c8c75d 100644
>> --- a/kexec/arch/ppc/crashdump-powerpc.c
>> +++ b/kexec/arch/ppc/crashdump-powerpc.c
>> @@ -262,10 +262,19 @@ static void ulltoa(unsigned long long i, char *str)
>> }
>> }
>>
>> +/* Append str to cmdline */
>> +static void add_cmdline(char *cmdline, char *str)
>> +{
>> + int cmdlen = strlen(cmdline) + strlen(str);
>> + if (cmdlen> (COMMAND_LINE_SIZE - 1))
>> + die("Command line overflow\n");
>> + strcat(cmdline, str);
>> +}
>> +
>> static int add_cmdline_param(char *cmdline, unsigned long long addr,
>> char *cmdstr, char *byte)
>> {
>> - int cmdlen, len, align = 1024;
>> + int align = 1024;
>> char str[COMMAND_LINE_SIZE], *ptr;
>>
>> /* Passing in =xxxK / =xxxM format. Saves space required in cmdline.*/
>> @@ -284,11 +293,8 @@ static int add_cmdline_param(char *cmdline,
>> unsigned long long addr,
>> ptr += strlen(str);
>> ulltoa(addr, ptr);
>> strcat(str, byte);
>> - len = strlen(str);
>> - cmdlen = strlen(cmdline) + len;
>> - if (cmdlen> (COMMAND_LINE_SIZE - 1))
>> - die("Command line overflow\n");
>> - strcat(cmdline, str);
>> +
>> + add_cmdline(cmdline, str);
>>
>> dbgprintf("Command line after adding elfcorehdr: %s\n", cmdline);
>>
>> @@ -365,6 +371,7 @@ int load_crashdump_segments(struct kexec_info
>> *info, char *mod_cmdline,
>> */
>> add_cmdline_param(mod_cmdline, elfcorehdr, " elfcorehdr=", "K");
>> add_cmdline_param(mod_cmdline, saved_max_mem, " savemaxmem=", "M");
>> + add_cmdline(mod_cmdline, " maxcpus=1");
>> return 0;
>> }
>>
>> diff --git a/kexec/arch/ppc/fixup_dtb.c b/kexec/arch/ppc/fixup_dtb.c
>> index e9890a4..f832026 100644
>> --- a/kexec/arch/ppc/fixup_dtb.c
>> +++ b/kexec/arch/ppc/fixup_dtb.c
>> @@ -172,6 +172,9 @@ static void fixup_reserve_regions(struct
>> kexec_info *info, char *blob_buf)
>> }
>> }
>>
>> +#if 0
>> + /* XXX: Do not reserve spin-table for CPUs. */
>> +
>> /* Add reserve regions for cpu-release-addr */
>> nodeoffset = fdt_node_offset_by_prop_value(blob_buf, -1,
>> "device_type", "cpu", 4);
>> while (nodeoffset != -FDT_ERR_NOTFOUND) {
>> @@ -201,6 +204,7 @@ static void fixup_reserve_regions(struct
>> kexec_info *info, char *blob_buf)
>> nodeoffset = fdt_node_offset_by_prop_value(blob_buf, nodeoffset,
>> "device_type", "cpu", 4);
>> }
>> +#endif
>>
>> out:
>> print_fdt_reserve_regions(blob_buf);
>>
>>
>> _______________________________________________
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>> http://lists.infradead.org/mailman/listinfo/kexec
>>
>
>
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