On Thursday 25 August 2016 12:31 PM, Dave Young wrote:
> On 08/10/16 at 03:35pm, Hari Bathini wrote:
>> When fadump is enabled, by default 5% of system RAM is reserved for
>> fadump kernel. While that works for most cases, it is not good enough
>> for every case.
>>
>> Currently, to override the default value, fadump supports specifying
>> memory to reserve with fadump_reserve_mem=size, where only a fixed size
>> can be specified. This patch adds support to specify memory size to
>> reserve for different memory ranges as below:
>>
>> fadump_reserve_mem=<range1>:<size1>[,<range2>:<size2>,...]
> Hi, Hari
Hi Dave,
> I do not understand why you need introduce the new cmdline param, what's
> the difference between the "fadump reserved" memory and the memory
I am not introducing a new parameter but adding a new syntax for
an existing parameter.
> reserved by "crashkernel="? Can fadump just use crashkernel= to reserve
> memory?
Not all syntaxes supported by crashkernel apply for fadump_reserve_mem.
Nonetheless, it is worth considering reuse of crashkernel parameter instead
of fadump_reserve_mem. Let me see what I can do about this..
Thanks
Hari
> Thanks
> Dave
>
>> Supporting range based input for "fadump_reserve_mem" parameter helps
>> using the same commandline parameter for different system memory sizes.
>>
>> Signed-off-by: Hari Bathini <hbathini at linux.vnet.ibm.com>
>> Reviewed-by: Mahesh J Salgaonkar <mahesh at linux.vnet.ibm.com>
>> ---
>>
>> Changes from v2:
>> 1. Updated changelog
>>
>>
>> arch/powerpc/kernel/fadump.c | 63 ++++++++++++++++++++++++++++++++++++------
>> 1 file changed, 54 insertions(+), 9 deletions(-)
>>
>> diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
>> index b3a6633..7c01b5b 100644
>> --- a/arch/powerpc/kernel/fadump.c
>> +++ b/arch/powerpc/kernel/fadump.c
>> @@ -193,6 +193,55 @@ static unsigned long init_fadump_mem_struct(struct fadump_mem_struct *fdm,
>> return addr;
>> }
>>
>> +/*
>> + * This function parses command line for fadump_reserve_mem=
>> + *
>> + * Supports the below two syntaxes:
>> + * 1. fadump_reserve_mem=size
>> + * 2. fadump_reserve_mem=ramsize-range:size[,...]
>> + *
>> + * Sets fw_dump.reserve_bootvar with the memory size
>> + * provided, 0 otherwise
>> + *
>> + * The function returns -EINVAL on failure, 0 otherwise.
>> + */
>> +static int __init parse_fadump_reserve_mem(void)
>> +{
>> + char *name = "fadump_reserve_mem=";
>> + char *fadump_cmdline = NULL, *cur;
>> +
>> + fw_dump.reserve_bootvar = 0;
>> +
>> + /* find fadump_reserve_mem and use the last one if there are many */
>> + cur = strstr(boot_command_line, name);
>> + while (cur) {
>> + fadump_cmdline = cur;
>> + cur = strstr(cur+1, name);
>> + }
>> +
>> + /* when no fadump_reserve_mem= cmdline option is provided */
>> + if (!fadump_cmdline)
>> + return 0;
>> +
>> + fadump_cmdline += strlen(name);
>> +
>> + /* for fadump_reserve_mem=size cmdline syntax */
>> + if (!is_colon_in_param(fadump_cmdline)) {
>> + fw_dump.reserve_bootvar = memparse(fadump_cmdline, NULL);
>> + return 0;
>> + }
>> +
>> + /* for fadump_reserve_mem=ramsize-range:size[,...] cmdline syntax */
>> + cur = fadump_cmdline;
>> + fw_dump.reserve_bootvar = parse_mem_range_size("fadump_reserve_mem",
>> + &cur, memblock_phys_mem_size());
>> + if (cur == fadump_cmdline) {
>> + return -EINVAL;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> /**
>> * fadump_calculate_reserve_size(): reserve variable boot area 5% of System RAM
>> *
>> @@ -212,12 +261,17 @@ static inline unsigned long fadump_calculate_reserve_size(void)
>> {
>> unsigned long size;
>>
>> + /* sets fw_dump.reserve_bootvar */
>> + parse_fadump_reserve_mem();
>> +
>> /*
>> * Check if the size is specified through fadump_reserve_mem= cmdline
>> * option. If yes, then use that.
>> */
>> if (fw_dump.reserve_bootvar)
>> return fw_dump.reserve_bootvar;
>> + else
>> + printk(KERN_INFO "fadump: calculating default boot size\n");
>>
>> /* divide by 20 to get 5% of value */
>> size = memblock_end_of_DRAM() / 20;
>> @@ -348,15 +402,6 @@ static int __init early_fadump_param(char *p)
>> }
>> early_param("fadump", early_fadump_param);
>>
>> -/* Look for fadump_reserve_mem= cmdline option */
>> -static int __init early_fadump_reserve_mem(char *p)
>> -{
>> - if (p)
>> - fw_dump.reserve_bootvar = memparse(p, &p);
>> - return 0;
>> -}
>> -early_param("fadump_reserve_mem", early_fadump_reserve_mem);
>> -
>> static void register_fw_dump(struct fadump_mem_struct *fdm)
>> {
>> int rc;
>>
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