* Jesper Juhl <[email protected]> wrote:
> > Ingo provided no information about his test setup and his patch was
> > a little strange, so I can't say that yet.
>
> What did you find strange about it? I'm currious. Sure it needs
> testing and of course it would be nice with some more details on
> Ingo's test setup.
My patch improves MySQL wall-clock performance by ~10% on a dual-core
box [see the numbers i cited in my initial mail, they were ran on a T60
with a 1.83 GHz Core2Duo] and by 7% on an 8-way box:
2.6.22-rc6:
#threads
9: transactions: 8440 (843.29 per sec.)
9: transactions: 8423 (841.18 per sec.)
9: transactions: 8511 (849.98 per sec.)
9: transactions: 8473 (846.23 per sec.)
2.6.22-rc6 + sys_time.patch:
#threads
9: transactions: 9043 (903.36 per sec.)
9: transactions: 9020 (900.78 per sec.)
9: transactions: 8974 (896.61 per sec.)
9: transactions: 9007 (899.97 per sec.)
[ to reproduce it, run sysbench 0.4.8 with --test=oltp --num-threads=9.
The other tests show similar speedup, so this is in no way limited to
OLTP. ]
in other words, if you are using MySQL in a serious way then this patch
provides you a real-world speedup equivalent to upgrading a 1.66 GHz
Core2Duo to a 1.83 GHz Core2Duo. I'd call that anything but "slightly
improved performance" ;-)
if you are curious why Roman's reaction to this patch was so negative:
i'm extremely curious myself too! ;-) That man, with his eternal
negativism (i dare anyone to point me to a _single_ lkml posting of
Roman where he gives any positive feedback to anyone) is a pure walking
mystery to me ;)
( whether there is any correlation between a decade long fundamental
suckage and stagnation of the Linux time and NTP subsystem and Roman's
decade long negative feedback presence in that area of code is left up
to the reader. :)
This current ... interesting piece of Roman about a _single_ trivial
unlikely() branch in do_gettimeofday() borders on the ridiculous. My
patch might be wrong for various reasons, but that single
'if (unlikely())' statement is not one of those reasons =B-)
Ingo
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
