Re: GCC's -fsplit-stack disturbing Mach's vm_allocate

[Thomas Schwinge]

Hi!

On Sat, 22 Jun 2013 08:15:46 -0700, Ian Lance Taylor <iant@google.com> wrote:
> Go can work without split stack.  In that case libgo will use much
> larger stacks for goroutines, to reduce the chance of running out of
> stack space (see StackMin in libgo/runtime/proc.c).  So the number of
> simultaneous goroutines that can be run will be limited.  This is
> usually OK on x86_64 but it does hamper Go programs running on 32-bit
> x86.

OK, but that's not the most pressing issue we're having right now.
Anyway, as it stands, the split-stack code doesn't work on Hurd, so I
disabled it in r200434 as follows:

gcc/
        * config/i386/gnu.h [TARGET_LIBC_PROVIDES_SSP]
        (TARGET_CAN_SPLIT_STACK, TARGET_THREAD_SPLIT_STACK_OFFSET):
        Undefine.

diff --git gcc/config/i386/gnu.h gcc/config/i386/gnu.h
index 35063e6..4a91c84 100644
--- gcc/config/i386/gnu.h
+++ gcc/config/i386/gnu.h
@@ -36,6 +36,12 @@ along with GCC.  If not, see <http://www.gnu.org/licenses/>.
 #endif
 
 #ifdef TARGET_LIBC_PROVIDES_SSP
+
+/* Not supported yet.  */
+# undef TARGET_THREAD_SSP_OFFSET
+
 /* Not supported yet.  */
-#undef TARGET_THREAD_SSP_OFFSET
+# undef TARGET_CAN_SPLIT_STACK
+# undef TARGET_THREAD_SPLIT_STACK_OFFSET
+
 #endif


Grüße,
 Thomas

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