From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sebastian Andrzej Siewior Subject: Re: [rfc patch v4.4-rt2] sched: fix up preempt lazy forward port Date: Mon, 1 Feb 2016 14:04:48 +0100 Message-ID: <56AF57F0.80300@linutronix.de> References: <1453108103.4123.4.camel@gmail.com> <20160118201828.GE12309@linutronix.de> <56A2196E.1020101@ti.com> <56A22693.4020304@linutronix.de> <20160122204018.GA3883@linutronix.de> <56A657DD.8080602@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: Thomas Gleixner , LKML , linux-rt-users To: Grygorii Strashko , Mike Galbraith Return-path: In-Reply-To: <56A657DD.8080602@ti.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-rt-users.vger.kernel.org On 01/25/2016 06:14 PM, Grygorii Strashko wrote: >> diff --git a/arch/arm/kernel/entry-common.S >> b/arch/arm/kernel/entry-common.S >> index 30a7228eaceb..c3bd6cbfce4b 100644 >> --- a/arch/arm/kernel/entry-common.S >> +++ b/arch/arm/kernel/entry-common.S >> @@ -36,7 +36,9 @@ >> UNWIND(.cantunwind ) >> disable_irq_notrace @ disable interrupts >> ldr r1, [tsk, #TI_FLAGS] @ re-check for syscall tracing >> - tst r1, #_TIF_SYSCALL_WORK | _TIF_WORK_MASK >> + tst r1, #((_TIF_SYSCALL_WORK | _TIF_WORK_MASK) & ~_TIF_SECCOMP) >> + bne fast_work_pending > ^^^^^^^^^^^^^^^^ > >> + tst r1, #_TIF_SECCOMP >> bne fast_work_pending > ^^^^^^^^^^^^^^^^^ > > Should it be "fast_work_pending" in both cases? Yes, I think so and it is, isn't it? The original is tst r1, #_TIF_SYSCALL_WORK | _TIF_WORK_MASK bne fast_work_pending and with the LAZY bits in it, the ASM opcode no longer works because the constant is too large (or has to many bits set). So I removed the _TIF_SECCOMP bit out of the mask and made two compare & jumps here. Sebastian