* [PATCH -rt] MIPS: Octeon: convert smp_reserve_lock to raw spinlock @ 2012-05-17 10:15 Yong Zhang 2012-05-17 16:30 ` David Daney 0 siblings, 1 reply; 4+ messages in thread From: Yong Zhang @ 2012-05-17 10:15 UTC (permalink / raw) To: linux-rt-users, linux-kernel; +Cc: ralf, david.daney, tglx From: Yong Zhang <yong.zhang@windriver.com> Because __cpu_disable is called in atomic context and spinlock is a mutex on -rt. Signed-off-by: Yong Zhang <yong.zhang0@gmail.com> --- arch/mips/cavium-octeon/smp.c | 6 +++--- 1 files changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/mips/cavium-octeon/smp.c b/arch/mips/cavium-octeon/smp.c index ef9c34a..473c72b 100644 --- a/arch/mips/cavium-octeon/smp.c +++ b/arch/mips/cavium-octeon/smp.c @@ -257,7 +257,7 @@ DEFINE_PER_CPU(int, cpu_state); extern void fixup_irqs(void); -static DEFINE_SPINLOCK(smp_reserve_lock); +static DEFINE_RAW_SPINLOCK(smp_reserve_lock); static int octeon_cpu_disable(void) { @@ -266,7 +266,7 @@ static int octeon_cpu_disable(void) if (cpu == 0) return -EBUSY; - spin_lock(&smp_reserve_lock); + raw_spin_lock(&smp_reserve_lock); set_cpu_online(cpu, false); cpu_clear(cpu, cpu_callin_map); @@ -277,7 +277,7 @@ static int octeon_cpu_disable(void) flush_cache_all(); local_flush_tlb_all(); - spin_unlock(&smp_reserve_lock); + raw_spin_unlock(&smp_reserve_lock); return 0; } -- 1.7.1 ^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH -rt] MIPS: Octeon: convert smp_reserve_lock to raw spinlock 2012-05-17 10:15 [PATCH -rt] MIPS: Octeon: convert smp_reserve_lock to raw spinlock Yong Zhang @ 2012-05-17 16:30 ` David Daney 2012-05-17 20:50 ` Ralf Baechle 0 siblings, 1 reply; 4+ messages in thread From: David Daney @ 2012-05-17 16:30 UTC (permalink / raw) To: Yong Zhang, ralf; +Cc: linux-rt-users, linux-kernel, david.daney, tglx On 05/17/2012 03:15 AM, Yong Zhang wrote: > From: Yong Zhang<yong.zhang@windriver.com> > > Because __cpu_disable is called in atomic context and spinlock > is a mutex on -rt. > > Signed-off-by: Yong Zhang<yong.zhang0@gmail.com> > --- > arch/mips/cavium-octeon/smp.c | 6 +++--- > 1 files changed, 3 insertions(+), 3 deletions(-) > > diff --git a/arch/mips/cavium-octeon/smp.c b/arch/mips/cavium-octeon/smp.c > index ef9c34a..473c72b 100644 > --- a/arch/mips/cavium-octeon/smp.c > +++ b/arch/mips/cavium-octeon/smp.c > @@ -257,7 +257,7 @@ DEFINE_PER_CPU(int, cpu_state); > > extern void fixup_irqs(void); > > -static DEFINE_SPINLOCK(smp_reserve_lock); > +static DEFINE_RAW_SPINLOCK(smp_reserve_lock); > Ralf added this in 773cb77d (MIPS: Cavium: Add CPU hotplugging code.) I'm not even sure what this lock is supposed to be protecting, so I would like Ralf to take a look. You can add an Acked-by: from me for either this patch as is, or if Ralf thinks it is OK, removing the lock entirely. In any event we can merge this via Ralf's tree. Thanks, David Daney > static int octeon_cpu_disable(void) > { > @@ -266,7 +266,7 @@ static int octeon_cpu_disable(void) > if (cpu == 0) > return -EBUSY; > > - spin_lock(&smp_reserve_lock); > + raw_spin_lock(&smp_reserve_lock); > > set_cpu_online(cpu, false); > cpu_clear(cpu, cpu_callin_map); > @@ -277,7 +277,7 @@ static int octeon_cpu_disable(void) > flush_cache_all(); > local_flush_tlb_all(); > > - spin_unlock(&smp_reserve_lock); > + raw_spin_unlock(&smp_reserve_lock); > > return 0; > } ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH -rt] MIPS: Octeon: convert smp_reserve_lock to raw spinlock 2012-05-17 16:30 ` David Daney @ 2012-05-17 20:50 ` Ralf Baechle 2012-05-18 2:29 ` Yong Zhang 0 siblings, 1 reply; 4+ messages in thread From: Ralf Baechle @ 2012-05-17 20:50 UTC (permalink / raw) To: David Daney; +Cc: Yong Zhang, linux-rt-users, linux-kernel, david.daney, tglx On Thu, May 17, 2012 at 09:30:42AM -0700, David Daney wrote: > Date: Thu, 17 May 2012 09:30:42 -0700 > From: David Daney <ddaney.cavm@gmail.com> > To: Yong Zhang <yong.zhang0@gmail.com>, ralf@linux-mips.org > CC: linux-rt-users@vger.kernel.org, linux-kernel@vger.kernel.org, > david.daney@cavium.com, tglx@linutronix.de > Subject: Re: [PATCH -rt] MIPS: Octeon: convert smp_reserve_lock to raw > spinlock > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > On 05/17/2012 03:15 AM, Yong Zhang wrote: > >From: Yong Zhang<yong.zhang@windriver.com> > > > >Because __cpu_disable is called in atomic context and spinlock > >is a mutex on -rt. > > > >Signed-off-by: Yong Zhang<yong.zhang0@gmail.com> > >--- > > arch/mips/cavium-octeon/smp.c | 6 +++--- > > 1 files changed, 3 insertions(+), 3 deletions(-) > > > >diff --git a/arch/mips/cavium-octeon/smp.c b/arch/mips/cavium-octeon/smp.c > >index ef9c34a..473c72b 100644 > >--- a/arch/mips/cavium-octeon/smp.c > >+++ b/arch/mips/cavium-octeon/smp.c > >@@ -257,7 +257,7 @@ DEFINE_PER_CPU(int, cpu_state); > > > > extern void fixup_irqs(void); > > > >-static DEFINE_SPINLOCK(smp_reserve_lock); > >+static DEFINE_RAW_SPINLOCK(smp_reserve_lock); > > > > Ralf added this in 773cb77d (MIPS: Cavium: Add CPU hotplugging code.) > > I'm not even sure what this lock is supposed to be protecting, so I > would like Ralf to take a look. > > You can add an Acked-by: from me for either this patch as is, or if > Ralf thinks it is OK, removing the lock entirely. > > In any event we can merge this via Ralf's tree. The 773cb77d patch has a long history but I think I first worked on it for Wind River Linux 2.0 which was 2.6.21-based, then broke it out and pushed it upstream. In 2.6.21 it was probably infected by the the smp_reserve_lock virus in the s390 code for no good reason. So I agree, the lock can be dropped and I'm queueing a patch to do so for 3.5. Ralf ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH -rt] MIPS: Octeon: convert smp_reserve_lock to raw spinlock 2012-05-17 20:50 ` Ralf Baechle @ 2012-05-18 2:29 ` Yong Zhang 0 siblings, 0 replies; 4+ messages in thread From: Yong Zhang @ 2012-05-18 2:29 UTC (permalink / raw) To: Ralf Baechle; +Cc: David Daney, linux-rt-users, linux-kernel, david.daney, tglx On Thu, May 17, 2012 at 10:50:03PM +0200, Ralf Baechle wrote: > On Thu, May 17, 2012 at 09:30:42AM -0700, David Daney wrote: > > Date: Thu, 17 May 2012 09:30:42 -0700 > > From: David Daney <ddaney.cavm@gmail.com> > > To: Yong Zhang <yong.zhang0@gmail.com>, ralf@linux-mips.org > > CC: linux-rt-users@vger.kernel.org, linux-kernel@vger.kernel.org, > > david.daney@cavium.com, tglx@linutronix.de > > Subject: Re: [PATCH -rt] MIPS: Octeon: convert smp_reserve_lock to raw > > spinlock > > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > > > On 05/17/2012 03:15 AM, Yong Zhang wrote: > > >From: Yong Zhang<yong.zhang@windriver.com> > > > > > >Because __cpu_disable is called in atomic context and spinlock > > >is a mutex on -rt. > > > > > >Signed-off-by: Yong Zhang<yong.zhang0@gmail.com> > > >--- > > > arch/mips/cavium-octeon/smp.c | 6 +++--- > > > 1 files changed, 3 insertions(+), 3 deletions(-) > > > > > >diff --git a/arch/mips/cavium-octeon/smp.c b/arch/mips/cavium-octeon/smp.c > > >index ef9c34a..473c72b 100644 > > >--- a/arch/mips/cavium-octeon/smp.c > > >+++ b/arch/mips/cavium-octeon/smp.c > > >@@ -257,7 +257,7 @@ DEFINE_PER_CPU(int, cpu_state); > > > > > > extern void fixup_irqs(void); > > > > > >-static DEFINE_SPINLOCK(smp_reserve_lock); > > >+static DEFINE_RAW_SPINLOCK(smp_reserve_lock); > > > > > > > Ralf added this in 773cb77d (MIPS: Cavium: Add CPU hotplugging code.) > > > > I'm not even sure what this lock is supposed to be protecting, so I > > would like Ralf to take a look. > > > > You can add an Acked-by: from me for either this patch as is, or if > > Ralf thinks it is OK, removing the lock entirely. > > > > In any event we can merge this via Ralf's tree. > > The 773cb77d patch has a long history but I think I first worked on it for > Wind River Linux 2.0 which was 2.6.21-based, then broke it out and pushed > it upstream. In 2.6.21 it was probably infected by the the smp_reserve_lock > virus in the s390 code for no good reason. So I agree, the lock can > be dropped and I'm queueing a patch to do so for 3.5. I'm OK with dropping it ;-) Thanks, Yong ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2012-05-18 2:29 UTC | newest] Thread overview: 4+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2012-05-17 10:15 [PATCH -rt] MIPS: Octeon: convert smp_reserve_lock to raw spinlock Yong Zhang 2012-05-17 16:30 ` David Daney 2012-05-17 20:50 ` Ralf Baechle 2012-05-18 2:29 ` Yong Zhang
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