Re: [PATCH] perf tools: Dont use openat()

[Eric Dumazet <eric.dumazet@gmail.com>]

Ulrich Drepper a écrit :
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> Eric Dumazet wrote:
>>> We can certainly remove that reliance - wanna send a patch for it?
> 
> Come on, the silliness has to stop.  The kernel must be recent and to
> use it adequately the C library also must be recent.  And "recent" is
> not even correct anymore: the functions are available for more then two
> years.  Removing the use of the modern interfaces makes everything
> slower and might even re-introduce race conditions my patch fixed.
> 

First time I ear that C library *must* be recent. This was never
mentionned in Documentation/Changes, "Minimal Requirements"

"perf list" can be 100x slower, and even racy, I dont mind. At all.

$ time perf list >/dev/null 2>/dev/null

real    0m0.001s
user    0m0.000s
sys     0m0.001s

With openat(), I cannot use "perf" on machines I can only change kernel,
since changing glibc is too risky for legacy apps. I could use static and
private glibc, but last time I tried this I lost few hours and failed.

If modern interfaces means : "Upgrade glibc or die, silly you..."
I prefer to be silly, and keep increasing linux usability, even
if I dont have the chance to have a modern lab with up2date distros.

BTW, oprofile compiles perfectly on RHEL4 and 'old' glibc.

Thanks