Date: Sat, 14 Dec 2013 23:11:15 +0100 From: Stefan Esser <se@freebsd.org> To: Steve Kargl <sgk@troutmask.apl.washington.edu> Cc: freebsd-current@freebsd.org, kib@freebsd.org Subject: Re: SVN commit 259045 breaks -CURRENT Message-ID: <52ACD783.7030203@freebsd.org> In-Reply-To: <20131214215904.GA24545@troutmask.apl.washington.edu> References: <52ACD12A.5020906@freebsd.org> <20131214215904.GA24545@troutmask.apl.washington.edu>
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Am 14.12.2013 22:59, schrieb Steve Kargl:
> On Sat, Dec 14, 2013 at 10:44:10PM +0100, Stefan Esser wrote:
>> I noticed a severe slowdown and network problems on my amd64 -CURRENT
>> system. By bisecting SVN revisions I identified the following commit
>> to be responsible:
>>
>> ----------------------------------------------------------------------
>> r259045 | kib | 2013-12-06 22:44:13 +0100 (Fri, 06 Dec 2013) | 9 lines
>>
>> Disallow optimizations which potentially remove boundary checks
>> for signed values due to a compiler authors considering integer
>> overflow as impossible.
>>
>> The change follows suit of other projects taking the same measure.
>> ----------------------------------------------------------------------
>>
>> This commit added the following line to /sys/conf/kern.mk:
>>
>> CFLAGS+= -fno-strict-overflow
>>
>>
>> The most obvious symptoms of the problem on my system are:
>>
>> 1) sa-spamd needs > 140 seconds to start
>> (instead of a few seconds)
>>
>> 2) SSH logins are very slow, many seconds of delay between connect
>> and password prompt, several seconds after password entry until
>> a command prompt appears (normally instantaneous)
>>
>
> Ah, so that explains the behavior I'm see. Just updated a circa Aug 3rd
> i386 FreeBSD to top-of-tree. My ssh logins to my work system take 30+
> seconds now. :(
You may want to test the attached patch, which reverts the above
mentioned commit.
Regards, STefan
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Index: /sys/conf/kern.mk
===================================================================
--- /sys/conf/kern.mk (revision 259396)
+++ /sys/conf/kern.mk (working copy)
@@ -148,12 +148,6 @@
CFLAGS+= -ffreestanding
#
-# Do not allow a compiler to optimize out overflow checks for signed
-# types.
-#
-CFLAGS+= -fno-strict-overflow
-
-#
# GCC SSP support
#
.if ${MK_SSP} != "no" && ${MACHINE_CPUARCH} != "ia64" && \
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