diff options
author | Krzysztof Helt <krzysztof.h1@wp.pl> | 2008-09-30 23:17:51 +0200 |
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committer | Ingo Molnar <mingo@elte.hu> | 2008-10-13 10:33:13 +0200 |
commit | 94f6bac1058fd59a8bd472d18c4b77f220d930b0 (patch) | |
tree | 298d0f96e6aa6bc414d3e7ad2db765ea8e864cff /ipc/msg.c | |
parent | e2ce07c8042975e52df4cec1f41faf15b83f2e42 (diff) |
x86: do not allow to optimize flag_is_changeable_p() (rev. 2)
The flag_is_changeable_p() is used by
has_cpuid_p() which can return different results
in the code sequence below:
if (!have_cpuid_p())
identify_cpu_without_cpuid(c);
/* cyrix could have cpuid enabled via c_identify()*/
if (!have_cpuid_p())
return;
Otherwise, the gcc 3.4.6 optimizes these two calls
into one which make the code not working correctly.
Cyrix cpus have the CPUID instruction enabled before
the second call to the have_cpuid_p() but
it is not detected due to the gcc optimization.
Thus the ARR registers (mtrr like) are not detected
on such a cpu.
Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'ipc/msg.c')
0 files changed, 0 insertions, 0 deletions