From: Cyril Bur <cyrilbur@gmail.com>
To: mikey@neuling.org, anton@samba.org, linuxppc-dev@ozlabs.org
Subject: [PATCH 4/8] powerpc: Explicitly disable math features when copying thread
Date: Wed, 18 Nov 2015 14:26:51 +1100 [thread overview]
Message-ID: <1447817215-15804-5-git-send-email-cyrilbur@gmail.com> (raw)
In-Reply-To: <1447817215-15804-1-git-send-email-cyrilbur@gmail.com>
With threads leaving the math bits enabled in their saved MSR to indicate
that the hardware is hot and a restore is not needed, children need to turn
it off as when they do get scheduled, there's no way their registers could
have been hot.
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
---
arch/powerpc/kernel/process.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 398f7bf..441d9e5 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1243,6 +1243,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
f = ret_from_fork;
}
+ childregs->msr &= ~(MSR_FP|MSR_VEC|MSR_VSX);
sp -= STACK_FRAME_OVERHEAD;
/*
--
2.6.2
next prev parent reply other threads:[~2015-11-18 3:28 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-18 3:26 [PATCH 0/8] FP/VEC/VSX switching optimisations Cyril Bur
2015-11-18 3:26 ` [PATCH 1/8] selftests/powerpc: Test the preservation of FPU and VMX regs across syscall Cyril Bur
2015-11-23 0:23 ` Michael Neuling
2015-11-23 0:58 ` Cyril Bur
2015-11-23 1:06 ` Michael Neuling
2015-11-18 3:26 ` [PATCH 2/8] selftests/powerpc: Test preservation of FPU and VMX regs across preemption Cyril Bur
2015-11-23 0:34 ` Michael Neuling
2015-11-18 3:26 ` [PATCH 3/8] selftests/powerpc: Test FPU and VMX regs in signal ucontext Cyril Bur
2015-11-19 11:36 ` [3/8] " Michael Ellerman
2015-11-23 1:04 ` [PATCH 3/8] " Michael Neuling
2015-11-18 3:26 ` Cyril Bur [this message]
2015-11-23 1:08 ` [PATCH 4/8] powerpc: Explicitly disable math features when copying thread Michael Neuling
2015-11-23 3:20 ` Cyril Bur
2015-11-18 3:26 ` [PATCH 5/8] powerpc: Restore FPU/VEC/VSX if previously used Cyril Bur
2015-11-20 11:01 ` Michael Ellerman
2015-11-22 22:18 ` Cyril Bur
2015-11-22 23:07 ` Michael Ellerman
2015-11-23 1:29 ` Michael Neuling
2015-11-18 3:26 ` [PATCH 6/8] powerpc: Add the ability to save FPU without giving it up Cyril Bur
2015-11-18 3:26 ` [PATCH 7/8] powerpc: Add the ability to save Altivec " Cyril Bur
2015-11-18 3:26 ` [PATCH 8/8] powerpc: Add the ability to save VSX " Cyril Bur
2015-11-18 14:51 ` [PATCH 0/8] FP/VEC/VSX switching optimisations David Laight
2015-11-18 23:01 ` Cyril Bur
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