Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1288363

Re: [PATCH v2 1/3] mm, printk: introduce new format string for flags

Show all headers | View raw

On Thu, Dec 10 2015, Steven Rostedt <rostedt@goodmis.org> wrote:

> On Thu, Dec 10, 2015 at 11:59:44AM +0900, Joonsoo Kim wrote:
>> 
>>   [page_ref:page_ref_unfreeze] bad op token &
>>   [page_ref:page_ref_set] bad op token &
>>   [page_ref:page_ref_mod_unless] bad op token &
>>   [page_ref:page_ref_mod_and_test] bad op token &
>>   [page_ref:page_ref_mod_and_return] bad op token &
>>   [page_ref:page_ref_mod] bad op token &
>>   [page_ref:page_ref_freeze] bad op token &
>> 
>> Following is the format I used.
>> 
>> TP_printk("pfn=0x%lx flags=%pgp count=%d mapcount=%d mapping=%p mt=%d val=%d ret=%d",
>>                 __entry->pfn, &__entry->flags, __entry->count,
>>                 __entry->mapcount, __entry->mapping, __entry->mt,
>>                 __entry->val, __entry->ret)
>> 
>> Could it be solved by 'trace-cmd' itself?
>> Or it's better to pass flags by value?
>> Or should I use something like show_gfp_flags()?
>
> Yes this can be solved in perf and trace-cmd via the parse-events.c file. And
> as soon as that happens, whatever method we decide upon becomes a userspace
> ABI. So don't think you can change it later.

So somewhat off-topic, but this reminds me of a question I've been
meaning to ask: What makes it safe to stash the pointer values in
vbin_printf and only dereference them later in bstr_printf? For plain
pointer printing (%p) it's of course not a problem, but quite a few of
the %p extensions do dereference the pointer in one way or another (at
least %p[dD], %p[mM], %p[iI], %ph, %pE, %pC, %pNF, %pU, %pa and probably
soon %pg).

Rasmus
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH 1/2] mm, printk: introduce new format string for flags Vlastimil Babka <vbabka@suse.cz> - 2015-11-30 17:20 +0100
  [PATCH 2/2] mm, page_owner: provide symbolic page flags and gfp_flags Vlastimil Babka <vbabka@suse.cz> - 2015-11-30 17:20 +0100
  Re: [PATCH 1/2] mm, printk: introduce new format string for flags Rasmus Villemoes <linux@rasmusvillemoes.dk> - 2015-12-02 12:10 +0100
    Re: [PATCH 1/2] mm, printk: introduce new format string for flags Vlastimil Babka <vbabka@suse.cz> - 2015-12-02 21:40 +0100
      Re: [PATCH 1/2] mm, printk: introduce new format string for flags Rasmus Villemoes <linux@rasmusvillemoes.dk> - 2015-12-03 13:40 +0100
        Re: [PATCH 1/2] mm, printk: introduce new format string for flags Vlastimil Babka <vbabka@suse.cz> - 2015-12-03 14:50 +0100
    [PATCH v2 3/3] mm, debug: move bad flags printing to bad_page() Vlastimil Babka <vbabka@suse.cz> - 2015-12-04 16:20 +0100
    [PATCH v2 2/3] mm, page_owner: provide symbolic page flags and gfp_flags Vlastimil Babka <vbabka@suse.cz> - 2015-12-04 16:20 +0100
    [PATCH v2 1/3] mm, printk: introduce new format string for flags Vlastimil Babka <vbabka@suse.cz> - 2015-12-04 16:20 +0100
      Re: [PATCH v2 1/3] mm, printk: introduce new format string for flags Rasmus Villemoes <linux@rasmusvillemoes.dk> - 2015-12-05 21:10 +0100
      Re: [PATCH v2 1/3] mm, printk: introduce new format string for flags Arnd Bergmann <arnd@arndb.de> - 2015-12-09 12:40 +0100
        Re: [PATCH v2 1/3] mm, printk: introduce new format string for flags Vlastimil Babka <vbabka@suse.cz> - 2015-12-09 21:50 +0100
        Re: [PATCH v2 1/3] mm, printk: introduce new format string for flags James Hogan <james.hogan@imgtec.com> - 2015-12-10 13:30 +0100
      Re: [PATCH v2 1/3] mm, printk: introduce new format string for flags Joonsoo Kim <iamjoonsoo.kim@lge.com> - 2015-12-10 04:00 +0100
        Re: [PATCH v2 1/3] mm, printk: introduce new format string for flags Steven Rostedt <rostedt@goodmis.org> - 2015-12-10 05:10 +0100
          Re: [PATCH v2 1/3] mm, printk: introduce new format string for flags Joonsoo Kim <iamjoonsoo.kim@lge.com> - 2015-12-10 05:50 +0100
          Re: [PATCH v2 1/3] mm, printk: introduce new format string for flags Rasmus Villemoes <linux@rasmusvillemoes.dk> - 2015-12-10 09:50 +0100
          Re: [PATCH v2 1/3] mm, printk: introduce new format string for flags Vlastimil Babka <vbabka@suse.cz> - 2015-12-10 11:10 +0100
      Re: [PATCH v2 1/3] mm, printk: introduce new format string for flags Steven Rostedt <rostedt@goodmis.org> - 2015-12-10 05:00 +0100
        Re: [PATCH v2 1/3] mm, printk: introduce new format string for flags Vlastimil Babka <vbabka@suse.cz> - 2015-12-10 11:00 +0100
  Re: [PATCH 1/2] mm, printk: introduce new format string for flags yalin wang <yalin.wang2010@gmail.com> - 2015-12-02 18:50 +0100
    Re: [PATCH 1/2] mm, printk: introduce new format string for flags Vlastimil Babka <vbabka@suse.cz> - 2015-12-02 22:20 +0100
      Re: [PATCH 1/2] mm, printk: introduce new format string for flags yalin wang <yalin.wang2010@gmail.com> - 2015-12-03 01:20 +0100
        Re: [PATCH 1/2] mm, printk: introduce new format string for flags Rasmus Villemoes <linux@rasmusvillemoes.dk> - 2015-12-03 09:10 +0100
          Re: [PATCH 1/2] mm, printk: introduce new format string for flags yalin wang <yalin.wang2010@gmail.com> - 2015-12-03 19:40 +0100
            Re: [PATCH 1/2] mm, printk: introduce new format string for flags yalin wang <yalin.wang2010@gmail.com> - 2015-12-04 02:10 +0100
            Re: [PATCH 1/2] mm, printk: introduce new format string for flags Vlastimil Babka <vbabka@suse.cz> - 2015-12-04 15:20 +0100
              Re: [PATCH 1/2] mm, printk: introduce new format string for flags Steven Rostedt <rostedt@goodmis.org> - 2015-12-10 05:10 +0100

csiph-web