Re: [patch v2] epoll use a single inode ...

Eric Dumazet
2007-03-07T06:57:25Z

Linus Torvalds a écrit :
>
> On Tue, 6 Mar 2007, Eric Dumazet wrote:
>> I did a user space program, attached to this mail.
>>
>> I rewrote the reciprocal_div() for i386 so that one multiply is used.
>
> Ok, this is definitely faster on Core 2 as well, so "numbers talk,
> bullshit walks". No more objections.

And the numbers were ? :)

>
> (That said, I bet you could do even better for octal and hex numbers, so
> if you *really* want to speed things up, you should just make a
> special-case routine for each base (there's just three of them), and you
> can then also optimize the base-10 thing much better (you can do two
> digits at a time by dividing by 100, etc)

Well, given that sprintf() is frequently called only for pipe/sockets
creation, we probably better :

1) wait a very clever idea to suppress individual dentry per pipe/sockets (no
more sprintf() at pipe/socket setup)

2) delay the sprintf() only if needed as you mentioned in a previous mail
(when someone wants ls -l /proc/pid/fd/....), since their dentries are not
anymore inserted in the global dcache hash, they could stay with a (nul) dname.