Hello!
On Thu, 27 Apr 2006, Kris Kennaway wrote:
Thanks for your suggestions, they've made a difference (though not as big
as one could hope).
On Thu, Apr 27, 2006 at 05:08:11PM +0300, Dmitry Pryanishnikov wrote:
makeoptions CONF_CFLAGS=-fno-builtin
Non-default option; this may conceivably affect performance.
The reason why I've initially included this option is the following
comment (NOTES from RELENG_6):
#
# CONF_CFLAGS gives some extra compiler flags that are added to ${CFLAGS}
# after most other flags. Here we use it to inhibit use of non-optimal
# gcc builtin functions (e.g., memcmp).
#
I've read this: using "CONF_CFLAGS=-fno-builtin" inhibits use of non-optimal
gcc builtin functions, so this option may be useful for getting max.
performance. Are this comment and my interpretation still correct now?
options INVARIANTS
options INVARIANT_SUPPORT
These definitely effect performance, much more in 5.x and 6.x (at the
10-20% level) than 4.x.
It's a pity - those help to catch a lot of software bugs ;(
options QUOTA
This definitely effects performance on 6.x since it makes your
filesystem giant-locked, which may also interfere with your network
processing.
It's also a pity.
%Sys %Intr %Idl
RELENG_4 + rl0 14 14 72
RELENG_4 + fxp0 14 10 76
RELENG_5 + rl0 40 30 30
RELENG_5 + fxp0 35 25 40
RELENG_6 + rl0 45 40 15
RELENG_6 + fxp0 45 35 20
Please retry without. Also make sure there are no other diagnostic
messages at boot time about e.g. mpsafenet being forced to 0.
I've removed all mentioned options and redone benchmarks. There are no
diagnostics about mpsafe* (last one I've seen due to IPSEC, and I've
replaced it with FAST_IPSEC+crypto before doing previous benchmarks).
New results are pretty close for RELENG_5 and RELENG_6:
%Sys %Intr %Idl "time md5 -t" wall clock time
RELENG_5 + rl0 33 23 44 1:41
RELENG_5 + fxp0 30 20 50 1:36
RELENG_6 + rl0 34 24 42 1:43
RELENG_6 + fxp0 30 20 50 1:40
So performance now is much better then before removal of
makeoptions CONF_CFLAGS=-fno-builtin
options INVARIANTS
options INVARIANT_SUPPORT
options QUOTA
(I'll try to find out which one of these takes which % of overhead when I
get free time), but still much worse then under RELENG_4, where this
particular (I'd say "quote common") usage pattern takes 24-28% of CPU time,
while under RELENG_5 / 6 it takes >= 50% ;(
Kris
Sincerely, Dmitry
--
Atlantis ISP, System Administrator
e-mail: [EMAIL PROTECTED]
nic-hdl: LYNX-RIPE
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