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Re: PATCH: Turn on -fomit-frame-pointer by default for 32bit Linux/x86
> Yes, I double-checked this morning.
Yes I found it after the post.
>
> The self-deadlock sequence observed with glibc-2.11.1 when calling
> backtrace() from inside TCMalloc malloc() was the same as in
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24724:
I think it's only doing this to avoid the sorting on initialization
time. The easy way to avoid it would be to call init_object()
for everything early, at the cost of some start up time.
> For example, libgcc_s.so.1 _Unwind_Backtrace (which is what glibc
> backtrace on x86 dispatches to) calls back into dl_iterate_phdr, which
> locks loader lock => kaboom!
Well still -- this stuff should be all fixable and it would seem
odd to leave 4% performance on the table just to avoid fixing a few bugs
in the infrastructure.
People often go to large jumps for much smaller performance improvements.
-Andi
--
ak@linux.intel.com -- Speaking for myself only.