Re: [PATCH 1/3] livepatch: Improve the search performance of module_kallsyms_on_each_symbol()

[Petr Mladek]

On Fri 2022-12-30 19:27:27, Zhen Lei wrote:
> Currently we traverse all symbols of all modules to find the specified
> function for the specified module. But in reality, we just need to find
> the given module and then traverse all the symbols in it.
> 
> Let's add a new parameter 'const char *modname' to function
> module_kallsyms_on_each_symbol(), then we can compare the module names
> directly in this function and call hook 'fn' after matching. If 'modname'
> is NULL, the symbols of all modules are still traversed for compatibility
> with other usage cases.
> 
> Phase1: mod1-->mod2..(subsequent modules do not need to be compared)
>                 |
> Phase2:          -->f1-->f2-->f3
> 
> Assuming that there are m modules, each module has n symbols on average,
> then the time complexity is reduced from O(m * n) to O(m) + O(n).
> 
> Signed-off-by: Zhen Lei <thunder.leizhen@xxxxxxxxxx>

Looks good to me:

Reviewed-by: Petr Mladek <pmladek@xxxxxxxx>

Best Regards,
Petr