* [PATCH -v2 6/8] kexec jump: fix for lockdep
@ 2008-08-08 6:52 ` Huang Ying
0 siblings, 0 replies; 10+ messages in thread
From: Huang Ying @ 2008-08-08 6:52 UTC (permalink / raw)
To: Eric W. Biederman, Pavel Machek, nigel, Rafael J. Wysocki,
Andrew Morton, Vivek Goyal, mingo, Linus Torvalds
Cc: Kexec Mailing List, linux-kernel
Replace local_irq_disable() with raw_local_irq_disable() to prevent
lockdep complain.
Signed-off-by: Huang Ying <ying.huang@intel.com>
---
arch/x86/kernel/machine_kexec_32.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/x86/kernel/machine_kexec_32.c
+++ b/arch/x86/kernel/machine_kexec_32.c
@@ -123,7 +123,7 @@ void machine_kexec(struct kimage *image)
tracer_disable();
/* Interrupts aren't acceptable while we reboot */
- local_irq_disable();
+ raw_local_irq_disable();
if (image->preserve_context) {
#ifdef CONFIG_X86_IO_APIC
_______________________________________________
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^ permalink raw reply [flat|nested] 10+ messages in thread* [PATCH -v2 6/8] kexec jump: fix for lockdep @ 2008-08-08 6:52 ` Huang Ying 0 siblings, 0 replies; 10+ messages in thread From: Huang Ying @ 2008-08-08 6:52 UTC (permalink / raw) To: Eric W. Biederman, Pavel Machek, nigel, Rafael J. Wysocki, Andrew Morton, Vivek Goyal, mingo, Linus Torvalds Cc: linux-kernel, Kexec Mailing List Replace local_irq_disable() with raw_local_irq_disable() to prevent lockdep complain. Signed-off-by: Huang Ying <ying.huang@intel.com> --- arch/x86/kernel/machine_kexec_32.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/x86/kernel/machine_kexec_32.c +++ b/arch/x86/kernel/machine_kexec_32.c @@ -123,7 +123,7 @@ void machine_kexec(struct kimage *image) tracer_disable(); /* Interrupts aren't acceptable while we reboot */ - local_irq_disable(); + raw_local_irq_disable(); if (image->preserve_context) { #ifdef CONFIG_X86_IO_APIC ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH -v2 6/8] kexec jump: fix for lockdep 2008-08-08 6:52 ` Huang Ying @ 2008-08-08 10:13 ` Peter Zijlstra -1 siblings, 0 replies; 10+ messages in thread From: Peter Zijlstra @ 2008-08-08 10:13 UTC (permalink / raw) To: Huang Ying Cc: nigel, Kexec Mailing List, linux-kernel, Rafael J. Wysocki, Eric W. Biederman, Pavel Machek, Andrew Morton, Linus Torvalds, mingo, Vivek Goyal On Fri, 2008-08-08 at 14:52 +0800, Huang Ying wrote: > Replace local_irq_disable() with raw_local_irq_disable() to prevent > lockdep complain. Uhhm, please provide more information - just using raw_* to silence lockdep is generally the wrong thing to do. > Signed-off-by: Huang Ying <ying.huang@intel.com> > > --- > arch/x86/kernel/machine_kexec_32.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > --- a/arch/x86/kernel/machine_kexec_32.c > +++ b/arch/x86/kernel/machine_kexec_32.c > @@ -123,7 +123,7 @@ void machine_kexec(struct kimage *image) > tracer_disable(); > > /* Interrupts aren't acceptable while we reboot */ > - local_irq_disable(); > + raw_local_irq_disable(); > > if (image->preserve_context) { > #ifdef CONFIG_X86_IO_APIC > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH -v2 6/8] kexec jump: fix for lockdep @ 2008-08-08 10:13 ` Peter Zijlstra 0 siblings, 0 replies; 10+ messages in thread From: Peter Zijlstra @ 2008-08-08 10:13 UTC (permalink / raw) To: Huang Ying Cc: Eric W. Biederman, Pavel Machek, nigel, Rafael J. Wysocki, Andrew Morton, Vivek Goyal, mingo, Linus Torvalds, linux-kernel, Kexec Mailing List On Fri, 2008-08-08 at 14:52 +0800, Huang Ying wrote: > Replace local_irq_disable() with raw_local_irq_disable() to prevent > lockdep complain. Uhhm, please provide more information - just using raw_* to silence lockdep is generally the wrong thing to do. > Signed-off-by: Huang Ying <ying.huang@intel.com> > > --- > arch/x86/kernel/machine_kexec_32.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > --- a/arch/x86/kernel/machine_kexec_32.c > +++ b/arch/x86/kernel/machine_kexec_32.c > @@ -123,7 +123,7 @@ void machine_kexec(struct kimage *image) > tracer_disable(); > > /* Interrupts aren't acceptable while we reboot */ > - local_irq_disable(); > + raw_local_irq_disable(); > > if (image->preserve_context) { > #ifdef CONFIG_X86_IO_APIC > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH -v2 6/8] kexec jump: fix for lockdep 2008-08-08 10:13 ` Peter Zijlstra @ 2008-08-11 0:59 ` Huang Ying -1 siblings, 0 replies; 10+ messages in thread From: Huang Ying @ 2008-08-11 0:59 UTC (permalink / raw) To: Peter Zijlstra Cc: nigel, Kexec Mailing List, linux-kernel, Rafael J. Wysocki, Eric W. Biederman, Pavel Machek, Andrew Morton, Linus Torvalds, mingo, Vivek Goyal On Fri, 2008-08-08 at 12:13 +0200, Peter Zijlstra wrote: > On Fri, 2008-08-08 at 14:52 +0800, Huang Ying wrote: > > Replace local_irq_disable() with raw_local_irq_disable() to prevent > > lockdep complain. > Uhhm, please provide more information - just using raw_* to silence > lockdep is generally the wrong thing to do. In traditional kexec, the new kernel will replace current one, so the irq is simply disabled. But now jumping back from kexeced kernel is supported, so the irq should be enabled again. The code sequence of irq during kexec jump is as follow: local_irq_disable(); /* in kernel_kexec() */ local_irq_disable(); /* in machine_kexec() */ local_irq_enable(); /* in kernel_kexec() */ The disable and enable is not match. Maybe another method is to use local_irq_save(), local_irq_restore() pair in machine_kexec(), so the disable and enable is matched. Best Regrards, Huang Ying _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH -v2 6/8] kexec jump: fix for lockdep @ 2008-08-11 0:59 ` Huang Ying 0 siblings, 0 replies; 10+ messages in thread From: Huang Ying @ 2008-08-11 0:59 UTC (permalink / raw) To: Peter Zijlstra Cc: Eric W. Biederman, Pavel Machek, nigel, Rafael J. Wysocki, Andrew Morton, Vivek Goyal, mingo, Linus Torvalds, linux-kernel, Kexec Mailing List On Fri, 2008-08-08 at 12:13 +0200, Peter Zijlstra wrote: > On Fri, 2008-08-08 at 14:52 +0800, Huang Ying wrote: > > Replace local_irq_disable() with raw_local_irq_disable() to prevent > > lockdep complain. > Uhhm, please provide more information - just using raw_* to silence > lockdep is generally the wrong thing to do. In traditional kexec, the new kernel will replace current one, so the irq is simply disabled. But now jumping back from kexeced kernel is supported, so the irq should be enabled again. The code sequence of irq during kexec jump is as follow: local_irq_disable(); /* in kernel_kexec() */ local_irq_disable(); /* in machine_kexec() */ local_irq_enable(); /* in kernel_kexec() */ The disable and enable is not match. Maybe another method is to use local_irq_save(), local_irq_restore() pair in machine_kexec(), so the disable and enable is matched. Best Regrards, Huang Ying ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH -v2 6/8] kexec jump: fix for lockdep 2008-08-11 0:59 ` Huang Ying @ 2008-08-11 6:09 ` Peter Zijlstra -1 siblings, 0 replies; 10+ messages in thread From: Peter Zijlstra @ 2008-08-11 6:09 UTC (permalink / raw) To: Huang Ying Cc: nigel, Kexec Mailing List, linux-kernel, Rafael J. Wysocki, Eric W. Biederman, Pavel Machek, Andrew Morton, Linus Torvalds, mingo, Vivek Goyal On Mon, 2008-08-11 at 08:59 +0800, Huang Ying wrote: > On Fri, 2008-08-08 at 12:13 +0200, Peter Zijlstra wrote: > > On Fri, 2008-08-08 at 14:52 +0800, Huang Ying wrote: > > > Replace local_irq_disable() with raw_local_irq_disable() to prevent > > > lockdep complain. > > Uhhm, please provide more information - just using raw_* to silence > > lockdep is generally the wrong thing to do. > > In traditional kexec, the new kernel will replace current one, so the > irq is simply disabled. But now jumping back from kexeced kernel is > supported, so the irq should be enabled again. > > The code sequence of irq during kexec jump is as follow: > > local_irq_disable(); /* in kernel_kexec() */ > local_irq_disable(); /* in machine_kexec() */ > local_irq_enable(); /* in kernel_kexec() */ > > The disable and enable is not match. Maybe another method is to use > local_irq_save(), local_irq_restore() pair in machine_kexec(), so the > disable and enable is matched. And its the machine kernel's lockdep instance that goes complain? whichever annotation gets used - and I think I can agree that raw_* might be approriate there, this should be accompanied with a rather elaborate changelog and preferably a comment in the code too. Without such we'll be wondering in the years to come WTH happens here. _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH -v2 6/8] kexec jump: fix for lockdep @ 2008-08-11 6:09 ` Peter Zijlstra 0 siblings, 0 replies; 10+ messages in thread From: Peter Zijlstra @ 2008-08-11 6:09 UTC (permalink / raw) To: Huang Ying Cc: Eric W. Biederman, Pavel Machek, nigel, Rafael J. Wysocki, Andrew Morton, Vivek Goyal, mingo, Linus Torvalds, linux-kernel, Kexec Mailing List On Mon, 2008-08-11 at 08:59 +0800, Huang Ying wrote: > On Fri, 2008-08-08 at 12:13 +0200, Peter Zijlstra wrote: > > On Fri, 2008-08-08 at 14:52 +0800, Huang Ying wrote: > > > Replace local_irq_disable() with raw_local_irq_disable() to prevent > > > lockdep complain. > > Uhhm, please provide more information - just using raw_* to silence > > lockdep is generally the wrong thing to do. > > In traditional kexec, the new kernel will replace current one, so the > irq is simply disabled. But now jumping back from kexeced kernel is > supported, so the irq should be enabled again. > > The code sequence of irq during kexec jump is as follow: > > local_irq_disable(); /* in kernel_kexec() */ > local_irq_disable(); /* in machine_kexec() */ > local_irq_enable(); /* in kernel_kexec() */ > > The disable and enable is not match. Maybe another method is to use > local_irq_save(), local_irq_restore() pair in machine_kexec(), so the > disable and enable is matched. And its the machine kernel's lockdep instance that goes complain? whichever annotation gets used - and I think I can agree that raw_* might be approriate there, this should be accompanied with a rather elaborate changelog and preferably a comment in the code too. Without such we'll be wondering in the years to come WTH happens here. ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH -v2 6/8] kexec jump: fix for lockdep 2008-08-11 6:09 ` Peter Zijlstra @ 2008-08-11 6:32 ` Huang Ying -1 siblings, 0 replies; 10+ messages in thread From: Huang Ying @ 2008-08-11 6:32 UTC (permalink / raw) To: Peter Zijlstra Cc: nigel, Kexec Mailing List, linux-kernel, Rafael J. Wysocki, Eric W. Biederman, Pavel Machek, Andrew Morton, Linus Torvalds, mingo, Vivek Goyal On Mon, 2008-08-11 at 08:09 +0200, Peter Zijlstra wrote: > On Mon, 2008-08-11 at 08:59 +0800, Huang Ying wrote: > > On Fri, 2008-08-08 at 12:13 +0200, Peter Zijlstra wrote: > > > On Fri, 2008-08-08 at 14:52 +0800, Huang Ying wrote: > > > > Replace local_irq_disable() with raw_local_irq_disable() to prevent > > > > lockdep complain. > > > Uhhm, please provide more information - just using raw_* to silence > > > lockdep is generally the wrong thing to do. > > > > In traditional kexec, the new kernel will replace current one, so the > > irq is simply disabled. But now jumping back from kexeced kernel is > > supported, so the irq should be enabled again. > > > > The code sequence of irq during kexec jump is as follow: > > > > local_irq_disable(); /* in kernel_kexec() */ > > local_irq_disable(); /* in machine_kexec() */ > > local_irq_enable(); /* in kernel_kexec() */ > > > > The disable and enable is not match. Maybe another method is to use > > local_irq_save(), local_irq_restore() pair in machine_kexec(), so the > > disable and enable is matched. > > And its the machine kernel's lockdep instance that goes complain? > > whichever annotation gets used - and I think I can agree that raw_* > might be approriate there, this should be accompanied with a rather > elaborate changelog and preferably a comment in the code too. Without > such we'll be wondering in the years to come WTH happens here. Sorry, I find there is no complain from lockdep. Un-paired irq disable/enable has no problem with lockdep, just increase something such as "redundant_hardirqs_off". Please ignore this thread. Best Regards, Huang Ying _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH -v2 6/8] kexec jump: fix for lockdep @ 2008-08-11 6:32 ` Huang Ying 0 siblings, 0 replies; 10+ messages in thread From: Huang Ying @ 2008-08-11 6:32 UTC (permalink / raw) To: Peter Zijlstra Cc: Eric W. Biederman, Pavel Machek, nigel, Rafael J. Wysocki, Andrew Morton, Vivek Goyal, mingo, Linus Torvalds, linux-kernel, Kexec Mailing List On Mon, 2008-08-11 at 08:09 +0200, Peter Zijlstra wrote: > On Mon, 2008-08-11 at 08:59 +0800, Huang Ying wrote: > > On Fri, 2008-08-08 at 12:13 +0200, Peter Zijlstra wrote: > > > On Fri, 2008-08-08 at 14:52 +0800, Huang Ying wrote: > > > > Replace local_irq_disable() with raw_local_irq_disable() to prevent > > > > lockdep complain. > > > Uhhm, please provide more information - just using raw_* to silence > > > lockdep is generally the wrong thing to do. > > > > In traditional kexec, the new kernel will replace current one, so the > > irq is simply disabled. But now jumping back from kexeced kernel is > > supported, so the irq should be enabled again. > > > > The code sequence of irq during kexec jump is as follow: > > > > local_irq_disable(); /* in kernel_kexec() */ > > local_irq_disable(); /* in machine_kexec() */ > > local_irq_enable(); /* in kernel_kexec() */ > > > > The disable and enable is not match. Maybe another method is to use > > local_irq_save(), local_irq_restore() pair in machine_kexec(), so the > > disable and enable is matched. > > And its the machine kernel's lockdep instance that goes complain? > > whichever annotation gets used - and I think I can agree that raw_* > might be approriate there, this should be accompanied with a rather > elaborate changelog and preferably a comment in the code too. Without > such we'll be wondering in the years to come WTH happens here. Sorry, I find there is no complain from lockdep. Un-paired irq disable/enable has no problem with lockdep, just increase something such as "redundant_hardirqs_off". Please ignore this thread. Best Regards, Huang Ying ^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2008-08-11 6:32 UTC | newest] Thread overview: 10+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2008-08-08 6:52 [PATCH -v2 6/8] kexec jump: fix for lockdep Huang Ying 2008-08-08 6:52 ` Huang Ying 2008-08-08 10:13 ` Peter Zijlstra 2008-08-08 10:13 ` Peter Zijlstra 2008-08-11 0:59 ` Huang Ying 2008-08-11 0:59 ` Huang Ying 2008-08-11 6:09 ` Peter Zijlstra 2008-08-11 6:09 ` Peter Zijlstra 2008-08-11 6:32 ` Huang Ying 2008-08-11 6:32 ` Huang Ying
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