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2008-04-19x86, fpu: lazy allocation of FPU area - v5Suresh Siddha
Only allocate the FPU area when the application actually uses FPU, i.e., in the first lazy FPU trap. This could save memory for non-fpu using apps. for example: on my system after boot, there are around 300 processes, with only 17 using FPU. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-19x86, fpu: split FPU state from task struct - v5Suresh Siddha
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>
2008-04-17x86: clean up i387.cIngo Molnar
minor coding style cleanups. Before: total: 0 errors, 3 warnings, 479 lines checked After: total: 0 errors, 1 warnings, 483 lines checked No code changed: arch/x86/kernel/i387.o: text data bss dec hex filename 2379 4 8 2391 957 i387.o.before 2379 4 8 2391 957 i387.o.after md5: e1434553a3b4ff1f52ad97a68b1fad8a i387.o.before.asm e1434553a3b4ff1f52ad97a68b1fad8a i387.o.after.asm Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-07x86: fix merge mistake in i387.cJan Beulich
convert_fxsr_to_user() in 2.6.24's i387_32.c did this, and convert_to_fxsr() also does the inverse, so I assume it's an oversight that it is no longer being done. [ mingo@elte.hu: we encode it this way because there's no space for the 'FPU Last Instruction Opcode' (->fop) field in the legacy user_i387_ia32_struct that PTRACE_GETFPREGS/PTRACE_SETFPREGS uses. it's probably pure legacy - i'd be surprised if any user-space relied on the FPU Last Opcode in any way. But indeed we used to do it previously so the most conservative thing is to preserve that piece of information. ] Signed-off-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-04x86, i387: fix ptrace leakage using init_fpu()Suresh Siddha
This bug got introduced by the recent i387 merge: commit 4421011120b2304e5c248ae4165a2704588aedf1 Author: Roland McGrath <roland@redhat.com> Date: Wed Jan 30 13:31:50 2008 +0100 x86: x86 i387 user_regset Current usage of unlazy_fpu() in ptrace specific routines is wrong. unlazy_fpu() will not init fpu if the task never used math. So the ptrace calls can expose the parent tasks FPU data in some cases. Replace it with the init_fpu() which will init the math state, if the task never used math before. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Acked-by: Thomas Gleixner <tglx@linutronix.de>
2008-02-19x86: make mxcsr_feature_mask static againAdrian Bunk
Signed-off-by: Adrian Bunk <bunk@kernel.org> Cc: Roland McGrath <roland@redhat.com> Cc: hpa@zytor.com Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30x86: x86 user_regset cleanupRoland McGrath
This removes a bunch of dead code that is no longer needed now that the user_regset interfaces are being used for all these jobs. Signed-off-by: Roland McGrath <roland@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30x86: x86 i387 user_regsetRoland McGrath
This revamps the i387 code to be shared across 32-bit, 64-bit, and 32-on-64. It does so by consolidating the code in one place based on the user_regset accessor interfaces. This switches 32-bit to using the i387_64.h header and 64-bit to using the i387.c that was previously i387_32.c, but that's what took the least cleanup in each file. Here i387.h is stubbed to always include i387_64.h rather than renaming the file, to keep this diff smaller and easier to read. Signed-off-by: Roland McGrath <roland@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30x86: i387 renamingRoland McGrath
This renames arch/x86/kernel/{i387_32.c => i387.c}. This is a pure renaming, but paves the way for merging the 32-bit and 64-bit versions of this code. Signed-off-by: Roland McGrath <roland@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>