This is the mail archive of the libc-help@sourceware.org mailing list for the glibc project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: Linux kernel headers


On Thu, Jul 2, 2009 at 8:06 AM, Petr Baudis<pasky@suse.cz> wrote:
> Actually, it's the other way around I think.
>
> --enable-kernel is the _minimal_ version glibc supports. It means that
> it assumes that features present in this kernel version are present and
> it does not waste cycles checking their presence and having
> compatibility code compiled in. So, if you specify 2.6.30, your glibc
> may not work with 2.6.29, but if you specify 2.6.29, your glibc will
> certainly work with 2.6.30 (albeit slightly less efficiently in theory).

Yes you're right.. I can't believe I got this wrong considering how
long I worked with the ill-fated *context routines for PowerPC.

> I actually plan to do some benchmarks on how various settings affect
> this since for historical reasons, in SUSE we still use
> --enable-kernel=2.6.4. If you know about any existing benchmarks,
> I would appreciate that. :-)

There are two big features that I can think of that may demonstrate
marked improvement.

Private Futex support and Per Thread Malloc Arena (i.e. experimental malloc).

Lack of accessible benchmarks certainly seems to be an issue.

Ryan


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]