On man, 2006-01-09 at 17:20 +0100, Peter S. Mazinger wrote: > On Sat, 7 Jan 2006, Mike Frysinger wrote: > > > On Saturday 07 January 2006 02:30, Natanael Copa wrote: > > > On lør, 2006-01-07 at 00:44 -0500, Mike Frysinger wrote: > > > > On Wednesday 04 January 2006 03:52, Natanael Copa wrote: > > > > > I got a report from someone who experienced lockups when using > > > > > gentoo-embedded built system (2.6.14-hardened-r1)
> > > When I disabled "Configure standard kernel features (for small > > > systems)" (gcc -Os) the problem magically went away. > > > > the kernel can be pretty sensitive to optimizations > > if kernel is built w/ gcc-3.4.4 and -Os (at least I had that for 2.4.x > kernels) it "optimizes away" memcmp and the kernels have gotten a patch > to overcome this, the same problem does not occur w/ gcc-3.3.x. > > > > So I think its a bug in gcc version 3.4.4 (Gentoo Hardened 3.4.4-r1, > > > ssp-3.4.4-1.0, pie-8.7.8) > > > > > > Makes me nervous because I have built everything with -Os. > > I have built everything w/ -Os and do not have trouble w/ it I have researched this and found out that it is not the -Os itself that causes this, but it is something else under "Configure standard kernel features (for small systems)". I'm not sure of exactly what but I know at least that it is not "Optimize for size". I have turned all options under "Configure standard kernel features (for small systems)" except "Load all symbols for debugging/kksymoops" (including optimize for size (-Os)) and done the netload test all night. This morning the computer was still up. When I have an unstable kernel it hangs after an hour or two. I have tried to flip the "futex support" and that did not make any difference (anyone who know how this affects uclibc based apps btw? Do I need futex support?) I think I have narrowed down the problem to one of those: * BUG() support * Enable full-sized data structures for core * Enable eventpoll support But exactly what, I dont know. If anyone here have had any problems with disabling one of those, I'm very interested to hear. Lots of bla bla here, I just thought it could be good for you guys to know that turning off of those might make your kernel unstable, while -Os should be ok with current gcc. -- Natanael Copa -- [email protected] mailing list
