* [PATCH 2.6.25.10 1/2] libata: fix locking for kmap_atomic
@ 2008-07-12 23:27 Jakub W. Jozwicki
2008-07-13 8:26 ` Andrew Morton
2008-07-13 10:25 ` Alan Cox
0 siblings, 2 replies; 9+ messages in thread
From: Jakub W. Jozwicki @ 2008-07-12 23:27 UTC (permalink / raw)
To: linux-kernel
Change locking surrounding kmap_atomic from local_irqsave to
local_irqsave_nort. This fixes issues with PREEMPT_RT.
Signed-off-by: Jakub Jozwicki <jozwicki@aster.pl>
--- linux-2.6.25.10/drivers/ata/libata-core.c 2008-07-03 05:46:47.000000000
+0200
+++ linux-2.6.25.10-rt7/drivers/ata/libata-core.c 2008-07-12
23:59:33.132140258 +0200
@@ -5157,14 +5157,14 @@
unsigned long flags;
/* FIXME: use a bounce buffer */
- local_irq_save(flags);
+ local_irq_save_nort(flags);
buf = kmap_atomic(page, KM_IRQ0);
/* do the actual data transfer */
ap->ops->data_xfer(qc->dev, buf + offset, qc->sect_size, do_write);
kunmap_atomic(buf, KM_IRQ0);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
} else {
buf = page_address(page);
ap->ops->data_xfer(qc->dev, buf + offset, qc->sect_size, do_write);
@@ -5294,14 +5294,14 @@
unsigned long flags;
/* FIXME: use bounce buffer */
- local_irq_save(flags);
+ local_irq_save_nort(flags);
buf = kmap_atomic(page, KM_IRQ0);
/* do the actual data transfer */
consumed = ap->ops->data_xfer(dev, buf + offset, count, rw);
kunmap_atomic(buf, KM_IRQ0);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
} else {
buf = page_address(page);
consumed = ap->ops->data_xfer(dev, buf + offset, count, rw);
^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [PATCH 2.6.25.10 1/2] libata: fix locking for kmap_atomic
2008-07-12 23:27 [PATCH 2.6.25.10 1/2] libata: fix locking for kmap_atomic Jakub W. Jozwicki
@ 2008-07-13 8:26 ` Andrew Morton
2008-07-13 13:17 ` Jakub W. Jozwicki
2008-07-13 10:25 ` Alan Cox
1 sibling, 1 reply; 9+ messages in thread
From: Andrew Morton @ 2008-07-13 8:26 UTC (permalink / raw)
To: Jakub W. Jozwicki; +Cc: linux-kernel
On Sun, 13 Jul 2008 01:27:36 +0200 "Jakub W. Jozwicki" <jozwicki@aster.pl> wrote:
> Change locking surrounding kmap_atomic from local_irqsave to
> local_irqsave_nort. This fixes issues with PREEMPT_RT.
>
I assume this is a -rt kernel patch.
>
> --- linux-2.6.25.10/drivers/ata/libata-core.c 2008-07-03 05:46:47.000000000
> +0200
> +++ linux-2.6.25.10-rt7/drivers/ata/libata-core.c 2008-07-12
> 23:59:33.132140258 +0200
> @@ -5157,14 +5157,14 @@
> unsigned long flags;
>
> /* FIXME: use a bounce buffer */
> - local_irq_save(flags);
> + local_irq_save_nort(flags);
eww. If we're going to have to do stuff like this in mainline then
there might be a revolt.
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH 2.6.25.10 1/2] libata: fix locking for kmap_atomic
2008-07-13 8:26 ` Andrew Morton
@ 2008-07-13 13:17 ` Jakub W. Jozwicki
2008-07-13 17:46 ` Jeremy Fitzhardinge
0 siblings, 1 reply; 9+ messages in thread
From: Jakub W. Jozwicki @ 2008-07-13 13:17 UTC (permalink / raw)
To: Andrew Morton; +Cc: linux-kernel, mingo, tglx
Sunday, 13 of July 2008 10:26:30 Andrew Morton napisał(a):
> On Sun, 13 Jul 2008 01:27:36 +0200 "Jakub W. Jozwicki" <jozwicki@aster.pl>
wrote:
> > Change locking surrounding kmap_atomic from local_irqsave to
> > local_irqsave_nort. This fixes issues with PREEMPT_RT.
>
> I assume this is a -rt kernel patch.
>
> > --- linux-2.6.25.10/drivers/ata/libata-core.c 2008-07-03
> > 05:46:47.000000000 +0200
> > +++ linux-2.6.25.10-rt7/drivers/ata/libata-core.c 2008-07-12
> > 23:59:33.132140258 +0200
> > @@ -5157,14 +5157,14 @@
> > unsigned long flags;
> >
> > /* FIXME: use a bounce buffer */
> > - local_irq_save(flags);
> > + local_irq_save_nort(flags);
>
> eww. If we're going to have to do stuff like this in mainline then
> there might be a revolt.
Sorry, this was for -rt only.
[ 17.012011] BUG: sleeping function called from invalid context IRQ-14(5732)
at arch/x86/mm/highmem_32.c:8
[ 17.012011] in_atomic():0 [00000000], irqs_disabled():1
[ 17.012011] Pid: 5732, comm: IRQ-14 Not tainted 2.6.25.10-rtXXX #11
[ 17.012011] [<c0120fc4>] __might_sleep+0xf1/0xf8
[ 17.012011] [<c011c035>] kmap+0x47/0x5a
[ 17.012011] [<c033e728>] ata_hsm_move+0x3d7/0x657
[ 17.012011] [<c0342fd6>] ata_interrupt+0x14e/0x1cb
[ 17.012011] [<c015c72c>] handle_IRQ_event+0x4e/0xd1
[ 17.012011] [<c015d266>] do_irqd+0x126/0x224
[ 17.012011] [<c015d140>] ? do_irqd+0x0/0x224
[ 17.012011] [<c013ae9d>] kthread+0x3b/0x62
[ 17.012011] [<c013ae62>] ? kthread+0x0/0x62
[ 17.012011] [<c0108287>] kernel_thread_helper+0x7/0x10
[ 17.012011] =======================
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH 2.6.25.10 1/2] libata: fix locking for kmap_atomic
2008-07-13 13:17 ` Jakub W. Jozwicki
@ 2008-07-13 17:46 ` Jeremy Fitzhardinge
2008-07-13 18:53 ` Jakub W. Jozwicki
0 siblings, 1 reply; 9+ messages in thread
From: Jeremy Fitzhardinge @ 2008-07-13 17:46 UTC (permalink / raw)
To: Jakub W. Jozwicki; +Cc: Andrew Morton, linux-kernel, mingo, tglx
Jakub W. Jozwicki wrote:
>
> Sorry, this was for -rt only.
>
> [ 17.012011] BUG: sleeping function called from invalid context IRQ-14(5732)
> at arch/x86/mm/highmem_32.c:8
> [ 17.012011] in_atomic():0 [00000000], irqs_disabled():1
> [ 17.012011] Pid: 5732, comm: IRQ-14 Not tainted 2.6.25.10-rtXXX #11
> [ 17.012011] [<c0120fc4>] __might_sleep+0xf1/0xf8
> [ 17.012011] [<c011c035>] kmap+0x47/0x5a
>
The subject says kmap_atomic, but this is kmap. It definitely makes no
sense to call kmap in an IRQ, regardless of the locking. There seems to
be a larger structural problem here.
> [ 17.012011] [<c033e728>] ata_hsm_move+0x3d7/0x657
> [ 17.012011] [<c0342fd6>] ata_interrupt+0x14e/0x1cb
> [ 17.012011] [<c015c72c>] handle_IRQ_event+0x4e/0xd1
> [ 17.012011] [<c015d266>] do_irqd+0x126/0x224
> [ 17.012011] [<c015d140>] ? do_irqd+0x0/0x224
> [ 17.012011] [<c013ae9d>] kthread+0x3b/0x62
> [ 17.012011] [<c013ae62>] ? kthread+0x0/0x62
> [ 17.012011] [<c0108287>] kernel_thread_helper+0x7/0x10
> [ 17.012011] =======================
>
J
^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [PATCH 2.6.25.10 1/2] libata: fix locking for kmap_atomic
2008-07-13 17:46 ` Jeremy Fitzhardinge
@ 2008-07-13 18:53 ` Jakub W. Jozwicki
2008-07-13 21:32 ` Jeremy Fitzhardinge
0 siblings, 1 reply; 9+ messages in thread
From: Jakub W. Jozwicki @ 2008-07-13 18:53 UTC (permalink / raw)
To: Jeremy Fitzhardinge; +Cc: Andrew Morton, linux-kernel, mingo, tglx
Sunday, 13 of July 2008 19:46:29 Jeremy Fitzhardinge napisał(a):
> Jakub W. Jozwicki wrote:
> > Sorry, this was for -rt only.
> >
> > [ 17.012011] BUG: sleeping function called from invalid context
> > IRQ-14(5732) at arch/x86/mm/highmem_32.c:8
> > [ 17.012011] in_atomic():0 [00000000], irqs_disabled():1
> > [ 17.012011] Pid: 5732, comm: IRQ-14 Not tainted 2.6.25.10-rtXXX #11
> > [ 17.012011] [<c0120fc4>] __might_sleep+0xf1/0xf8
> > [ 17.012011] [<c011c035>] kmap+0x47/0x5a
>
> The subject says kmap_atomic, but this is kmap. It definitely makes no
> sense to call kmap in an IRQ, regardless of the locking. There seems to
> be a larger structural problem here.
>
--- linux-2.6.25.8-rt7.orig/include/asm-x86/highmem.h 2008-06-23
19:12:47.000000000 -0400
+++ linux-2.6.25.8-rt7/include/asm-x86/highmem.h 2008-06-23
19:13:58.000000000 -0400
+/*
+ * on PREEMPT_RT kmap_atomic() is a wrapper that uses kmap():
+ */
+#ifdef CONFIG_PREEMPT_RT
+# define kmap_atomic_prot(page, type, prot) ({ pagefault_disable();
kmap(page); })
+# define kmap_atomic(page, type) ({ pagefault_disable(); kmap(page); })
+# define kmap_atomic_pfn(pfn, type) kmap(pfn_to_page(pfn))
+# define kunmap_atomic(kvaddr, type) do { pagefault_enable();
kunmap_virt(kvaddr); } while(0)
+# define kmap_atomic_to_page(kvaddr) kmap_to_page(kvaddr)
+#else
+# define kmap_atomic_prot(page, type, prot) __kmap_atomic_prot(page, type,
prot)
+# define kmap_atomic(page, type) __kmap_atomic(page, type)
+# define kmap_atomic_pfn(pfn, type) __kmap_atomic_pfn(pfn, type)
+# define kunmap_atomic(kvaddr, type) __kunmap_atomic(kvaddr, type)
+# define kmap_atomic_to_page(kvaddr) __kmap_atomic_to_page(kvaddr)
+#endif
+
^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [PATCH 2.6.25.10 1/2] libata: fix locking for kmap_atomic
2008-07-13 18:53 ` Jakub W. Jozwicki
@ 2008-07-13 21:32 ` Jeremy Fitzhardinge
0 siblings, 0 replies; 9+ messages in thread
From: Jeremy Fitzhardinge @ 2008-07-13 21:32 UTC (permalink / raw)
To: Jakub W. Jozwicki; +Cc: Andrew Morton, linux-kernel, mingo, tglx
Jakub W. Jozwicki wrote:
> Sunday, 13 of July 2008 19:46:29 Jeremy Fitzhardinge napisał(a):
>
>> Jakub W. Jozwicki wrote:
>>
>>> Sorry, this was for -rt only.
>>>
>>> [ 17.012011] BUG: sleeping function called from invalid context
>>> IRQ-14(5732) at arch/x86/mm/highmem_32.c:8
>>> [ 17.012011] in_atomic():0 [00000000], irqs_disabled():1
>>> [ 17.012011] Pid: 5732, comm: IRQ-14 Not tainted 2.6.25.10-rtXXX #11
>>> [ 17.012011] [<c0120fc4>] __might_sleep+0xf1/0xf8
>>> [ 17.012011] [<c011c035>] kmap+0x47/0x5a
>>>
>> The subject says kmap_atomic, but this is kmap. It definitely makes no
>> sense to call kmap in an IRQ, regardless of the locking. There seems to
>> be a larger structural problem here.
>>
>>
>
> --- linux-2.6.25.8-rt7.orig/include/asm-x86/highmem.h 2008-06-23
> 19:12:47.000000000 -0400
> +++ linux-2.6.25.8-rt7/include/asm-x86/highmem.h 2008-06-23
> 19:13:58.000000000 -0400
>
>
> +/*
> + * on PREEMPT_RT kmap_atomic() is a wrapper that uses kmap():
>
OK, I guess the "structural problem" is RT ;)
J
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH 2.6.25.10 1/2] libata: fix locking for kmap_atomic
2008-07-12 23:27 [PATCH 2.6.25.10 1/2] libata: fix locking for kmap_atomic Jakub W. Jozwicki
2008-07-13 8:26 ` Andrew Morton
@ 2008-07-13 10:25 ` Alan Cox
2008-07-13 13:30 ` Jakub W. Jozwicki
1 sibling, 1 reply; 9+ messages in thread
From: Alan Cox @ 2008-07-13 10:25 UTC (permalink / raw)
To: Jakub W. Jozwicki; +Cc: linux-kernel, jgarzik
On Sun, 13 Jul 2008 01:27:36 +0200
"Jakub W. Jozwicki" <jozwicki@aster.pl> wrote:
> Change locking surrounding kmap_atomic from local_irqsave to
> local_irqsave_nort. This fixes issues with PREEMPT_RT.
>
> Signed-off-by: Jakub Jozwicki <jozwicki@aster.pl>
The right way to fix this is to use a bounce buffer. I sent Jeff patches
to do that a couple of times. I'm not sure what has happened to them
since ? So NAK this, we should apply the patch to actually fix the bug
instead.
Jeff ?
Alan
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH 2.6.25.10 1/2] libata: fix locking for kmap_atomic
2008-07-13 10:25 ` Alan Cox
@ 2008-07-13 13:30 ` Jakub W. Jozwicki
2008-07-13 14:15 ` Alan Cox
0 siblings, 1 reply; 9+ messages in thread
From: Jakub W. Jozwicki @ 2008-07-13 13:30 UTC (permalink / raw)
To: Alan Cox; +Cc: linux-kernel, jgarzik, mingo, tglx
Sunday, 13 of July 2008 12:25:43 Alan Cox napisał(a):
> On Sun, 13 Jul 2008 01:27:36 +0200
>
> "Jakub W. Jozwicki" <jozwicki@aster.pl> wrote:
> > Change locking surrounding kmap_atomic from local_irqsave to
> > local_irqsave_nort. This fixes issues with PREEMPT_RT.
> >
> > Signed-off-by: Jakub Jozwicki <jozwicki@aster.pl>
>
> The right way to fix this is to use a bounce buffer. I sent Jeff patches
> to do that a couple of times. I'm not sure what has happened to them
> since ? So NAK this, we should apply the patch to actually fix the bug
> instead.
>
> Jeff ?
>
> Alan
Sent patch was for:
[ 16.787021] BUG: sleeping function called from invalid context IRQ-14(5730)
at arch/x86/mm/highmem_32.c:8
[ 16.787021] in_atomic():0 [00000000], irqs_disabled():1
[ 16.787021] Pid: 5730, comm: IRQ-14 Not tainted 2.6.25.10-rtXXX #12
[ 16.787021] [<c0120fc4>] __might_sleep+0xf1/0xf8
[ 16.787021] [<c011c035>] kmap+0x47/0x5a
[ 16.787021] [<c03442b2>] ata_scsi_rbuf_get+0x23/0x31
[ 16.787021] [<c0345975>] atapi_qc_complete+0x252/0x2c5
[ 16.787021] [<c012edee>] ? irq_exit+0x7b/0x7e
[ 16.787021] [<c0109727>] ? do_IRQ+0x6e/0x87
[ 16.787021] [<c033d041>] __ata_qc_complete+0x8e/0x93
[ 16.787021] [<c033ddfb>] ata_qc_complete+0x182/0x188
[ 16.787021] [<c033e188>] ata_hsm_qc_complete+0xa1/0xa5
[ 16.787021] [<c033e8fd>] ata_hsm_move+0x5dd/0x628
[ 16.787021] [<c0342f76>] ata_interrupt+0x14e/0x1cb
[ 16.787021] [<c015c72c>] handle_IRQ_event+0x4e/0xd1
[ 16.787021] [<c015d266>] do_irqd+0x126/0x224
[ 16.787021] [<c015d140>] ? do_irqd+0x0/0x224
[ 16.787021] [<c013ae9d>] kthread+0x3b/0x62
[ 16.787021] [<c013ae62>] ? kthread+0x0/0x62
[ 16.787021] [<c0108287>] kernel_thread_helper+0x7/0x10
[ 16.787021] =======================
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH 2.6.25.10 1/2] libata: fix locking for kmap_atomic
2008-07-13 13:30 ` Jakub W. Jozwicki
@ 2008-07-13 14:15 ` Alan Cox
0 siblings, 0 replies; 9+ messages in thread
From: Alan Cox @ 2008-07-13 14:15 UTC (permalink / raw)
To: Jakub W. Jozwicki; +Cc: linux-kernel, jgarzik, mingo, tglx
> Sent patch was for:
>
> [ 16.787021] BUG: sleeping function called from invalid context IRQ-14(5730)
> at arch/x86/mm/highmem_32.c:8
Fine - but the right fix is still to apply the patches that use a bounce
buffer, otherwise you might paper over the warning but you'll trash rt
performance. It needs fixing anyway especially with Tejun's changes to
the ATAPI logic to use PIO more often
Alan
^ permalink raw reply [flat|nested] 9+ messages in thread
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Thread overview: 9+ messages (download: mbox.gz follow: Atom feed
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2008-07-12 23:27 [PATCH 2.6.25.10 1/2] libata: fix locking for kmap_atomic Jakub W. Jozwicki
2008-07-13 8:26 ` Andrew Morton
2008-07-13 13:17 ` Jakub W. Jozwicki
2008-07-13 17:46 ` Jeremy Fitzhardinge
2008-07-13 18:53 ` Jakub W. Jozwicki
2008-07-13 21:32 ` Jeremy Fitzhardinge
2008-07-13 10:25 ` Alan Cox
2008-07-13 13:30 ` Jakub W. Jozwicki
2008-07-13 14:15 ` Alan Cox
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