Re: [PATCH v3 3/4] x86, kdump: Change crashkernel_high/low= to crashkernel=;high/low

From: H. Peter Anvin
Date: Tue Apr 09 2013 - 11:01:32 EST


Please, no semicolons. We already have established syntax for suboptions (option=suboption,suboption,...) and suboptions with parameters (option=suboption:value,...)

Vivek Goyal <vgoyal@xxxxxxxxxx> wrote:

>On Thu, Apr 04, 2013 at 03:17:01PM -0700, Yinghai Lu wrote:
>
>[..]
>> @@ -1360,37 +1369,80 @@ static int __init parse_crashkernel_simp
>>
>> if (*cur == '@')
>> *crash_base = memparse(cur+1, &cur);
>> - else if (*cur != ' ' && *cur != '\0') {
>> - pr_warning("crashkernel: unrecognized char\n");
>> - return -EINVAL;
>> + else {
>> + int i;
>> +
>> + /* check with known suffix */
>> + for (i = 0; suffix_tbl[i]; i++)
>> + if (!strncmp(cur, suffix_tbl[i], strlen(suffix_tbl[i])))
>> + return 0;
>> +
>
>So crashkernel=X@Y;high is a valid syntax? Looks like we will reserve
>X amount of RAM at base Y and ignore "high" or "low".
>
>[..]
>> static int __init __parse_crashkernel(char *cmdline,
>> unsigned long long system_ram,
>> unsigned long long *crash_size,
>> unsigned long long *crash_base,
>> - const char *name)
>> + const char *name,
>> + const char *suffix,
>> + bool simple_only)
>> {
>> - char *p = cmdline, *ck_cmdline = NULL;
>> char *first_colon, *first_space;
>> + char *ck_cmdline;
>>
>> BUG_ON(!crash_size || !crash_base);
>> *crash_size = 0;
>> *crash_base = 0;
>>
>> - /* find crashkernel and use the last one if there are more */
>> - p = strstr(p, name);
>> - while (p) {
>> - ck_cmdline = p;
>> - p = strstr(p+1, name);
>> - }
>> + ck_cmdline = get_last_crashkernel(cmdline, name, suffix);
>>
>> if (!ck_cmdline)
>> return -EINVAL;
>> @@ -1403,23 +1455,30 @@ static int __init __parse_crashkernel(ch
>> */
>> first_colon = strchr(ck_cmdline, ':');
>> first_space = strchr(ck_cmdline, ' ');
>> - if (first_colon && (!first_space || first_colon < first_space))
>> - return parse_crashkernel_mem(ck_cmdline, system_ram,
>> - crash_size, crash_base);
>> - else
>> + if (first_colon && (!first_space || first_colon < first_space)) {
>> + if (simple_only)
>> + return -EINVAL;
>> + else
>> + return parse_crashkernel_mem(ck_cmdline, system_ram,
>> + crash_size, crash_base);
>> + } else
>> return parse_crashkernel_simple(ck_cmdline, crash_size,
>> crash_base);
>
>Why don't we structure it little differently. Now we seem to have 3
>categories of crashkernel= parameters.
>
>- crashkernel_simple (crashkernel=X or crashkernel=X@Y)
>- crashkernel_mem (crashkernel=range:size,.....)
>- crashkerenl_high_low_suffix (crashkernel=X;high or crashkernel=Y;low)
>
>if (suffix) {
> parse_crashkernel_high_low_suffix()
>} else {
> if (first_colon.....)
> parse_crashkernel_mem()
> else
> parse_crashkernel_simple();
>}
>
>And now you should not require "simple_only" function parameter and you
>can also do strict syntax checking for each type of crashkernel=
>parameter.
>
>Thanks
>Vivek

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