Re: [patch 0/4] Series to allow a "const" file_operations struct

Eric Dumazet
2006-01-06T22:46:22Z

Arjan van de Ven a écrit :
> On Fri, 2006-01-06 at 22:45 +0100, Arjan van de Ven wrote:
>> Hi,
>>
>> this series allows drivers to have "const" file_operations, by making
>> the f_ops field in the inode const. This has another benefit, there have
>
> ok there was a sentence missing here. The first benefit is that this
> moves these hot datastructures to the rodata section, which means they
> won't accidentally be doing false cacheline sharing.
>

Definitly a good thing I agree.

But your patches miss to really declare all 'struct file_operations' as const,
dont they ?

On my x86_64 machine, I managed to reduce by 10% .data section by moving all
file_operations, but also 'address_space_operations', 'inode_operations,
super_operations, dentry_operations, seq_operations, ... to rodata section.

size vmlinux*
text data bss dec hex filename
2476156 522236 244868 3243260 317cfc vmlinux
2588685 571348 246692 3406725 33fb85 vmlinux.old

Eric