Re: [PATCH 3/3] x86/ftrace: Use text_poke()

From: Daniel Bristot de Oliveira
Date: Fri Oct 04 2019 - 10:45:07 EST


On 04/10/2019 15:40, Steven Rostedt wrote:
> On Fri, 4 Oct 2019 10:10:47 +0200
> Daniel Bristot de Oliveira <bristot@xxxxxxxxxx> wrote:
>
>> [ In addition ]
>>
>> Currently, ftrace_rec entries are ordered inside the group of functions, but
>> "groups of function" are not ordered. So, the current int3 handler does a (*):
>>
>> for_each_group_of_functions:
>> check if the ip is in the range ----> n by the number of groups.
>> do a bsearch. ----> log(n) by the numbers of entry
>> in the group.
>>
>> If, instead, it uses an ordered vector, the complexity would be log(n) by the
>> total number of entries, which is better. So, how bad is the idea of:
> BTW, I'm currently rewriting the grouping of the vectors, in order to
> shrink the size of each dyn_ftrace_rec (as we discussed at Kernel
> Recipes). I can make the groups all sorted in doing so, thus we can
> load the sorted if that's needed, without doing anything special.
>

Good! if you do they sorted and store the amount of entries in a variable, we
can have things done for a future "optimized" version.

-- Daniel