x86, fpu: split FPU state from task struct - v5
Split the FPU save area from the task struct. This allows easy migration of FPU context, and it's generally cleaner. It also allows the following two optimizations: 1) only allocate when the application actually uses FPU, so in the first lazy FPU trap. This could save memory for non-fpu using apps. Next patch does this lazy allocation. 2) allocate the right size for the actual cpu rather than 512 bytes always. Patches enabling xsave/xrstor support (coming shortly) will take advantage of this. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:

committed by
Ingo Molnar

parent
fa5c463941
commit
61c4628b53
@@ -1180,8 +1180,8 @@ u_char __user *fstenv(fpu_addr_modes addr_modes, u_char __user *d)
|
||||
control_word |= 0xffff0040;
|
||||
partial_status = status_word() | 0xffff0000;
|
||||
fpu_tag_word |= 0xffff0000;
|
||||
I387.soft.fcs &= ~0xf8000000;
|
||||
I387.soft.fos |= 0xffff0000;
|
||||
I387->soft.fcs &= ~0xf8000000;
|
||||
I387->soft.fos |= 0xffff0000;
|
||||
#endif /* PECULIAR_486 */
|
||||
if (__copy_to_user(d, &control_word, 7 * 4))
|
||||
FPU_abort;
|
||||
|
Reference in New Issue
Block a user