Re: [PATCH] hpsa: fix warning with smp_processor_id() in preemptible
On Mon, Aug 12, 2013 at 09:33:32AM -0400, John Kacur wrote: > > > - Original Message - > > * John Kacur | 2013-07-26 16:42:30 [+0200]: > > > > >Signed-off-by: John Kacur > > >Acked-by: Stephen > > > > ping. > > > > I checked the branches for-next, scsi-fixes, fixes and misc at [0] and I > > didn't see it. I'm going to take this for 3.10-rt but please don't lose > > it on its way to Linus :) > > > > [0] git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi.git > > > I hope it was clear to everyone that this patch was intended for upstream. > It was discovered by running the real-time kernel, but it exposes a (minor) > problem > that should be fixed in the mainline kernel. Please apply it there Stephen, > and > push it upstream appropriately. I don't have such pushing abilities. Acking it as I've done is all I can do. Bug James. :) -- steve -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] hpsa: fix warning with smp_processor_id() in preemptible
- Original Message - > * John Kacur | 2013-07-26 16:42:30 [+0200]: > > >Signed-off-by: John Kacur > >Acked-by: Stephen > > ping. > > I checked the branches for-next, scsi-fixes, fixes and misc at [0] and I > didn't see it. I'm going to take this for 3.10-rt but please don't lose > it on its way to Linus :) > > [0] git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi.git I hope it was clear to everyone that this patch was intended for upstream. It was discovered by running the real-time kernel, but it exposes a (minor) problem that should be fixed in the mainline kernel. Please apply it there Stephen, and push it upstream appropriately. Thank You. John Kacur -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] hpsa: fix warning with smp_processor_id() in preemptible
* John Kacur | 2013-07-26 16:42:30 [+0200]: >Signed-off-by: John Kacur >Acked-by: Stephen ping. I checked the branches for-next, scsi-fixes, fixes and misc at [0] and I didn't see it. I'm going to take this for 3.10-rt but please don't lose it on its way to Linus :) [0] git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi.git Sebastian -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] hpsa: fix warning with smp_processor_id() in preemptible
* John Kacur | 2013-07-26 16:42:30 [+0200]: Signed-off-by: John Kacur jka...@redhat.com Acked-by: Stephen scame...@beardog.cce.hp.com ping. I checked the branches for-next, scsi-fixes, fixes and misc at [0] and I didn't see it. I'm going to take this for 3.10-rt but please don't lose it on its way to Linus :) [0] git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi.git Sebastian -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] hpsa: fix warning with smp_processor_id() in preemptible
- Original Message - * John Kacur | 2013-07-26 16:42:30 [+0200]: Signed-off-by: John Kacur jka...@redhat.com Acked-by: Stephen scame...@beardog.cce.hp.com ping. I checked the branches for-next, scsi-fixes, fixes and misc at [0] and I didn't see it. I'm going to take this for 3.10-rt but please don't lose it on its way to Linus :) [0] git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi.git I hope it was clear to everyone that this patch was intended for upstream. It was discovered by running the real-time kernel, but it exposes a (minor) problem that should be fixed in the mainline kernel. Please apply it there Stephen, and push it upstream appropriately. Thank You. John Kacur -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] hpsa: fix warning with smp_processor_id() in preemptible
On Mon, Aug 12, 2013 at 09:33:32AM -0400, John Kacur wrote: - Original Message - * John Kacur | 2013-07-26 16:42:30 [+0200]: Signed-off-by: John Kacur jka...@redhat.com Acked-by: Stephen scame...@beardog.cce.hp.com ping. I checked the branches for-next, scsi-fixes, fixes and misc at [0] and I didn't see it. I'm going to take this for 3.10-rt but please don't lose it on its way to Linus :) [0] git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi.git I hope it was clear to everyone that this patch was intended for upstream. It was discovered by running the real-time kernel, but it exposes a (minor) problem that should be fixed in the mainline kernel. Please apply it there Stephen, and push it upstream appropriately. I don't have such pushing abilities. Acking it as I've done is all I can do. Bug James. :) -- steve -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH] hpsa: fix warning with smp_processor_id() in preemptible
>From 4c01ac362210c38cdbaddd0a75c24c7070e77dfa Mon Sep 17 00:00:00 2001 From: John Kacur Date: Fri, 26 Jul 2013 16:06:18 +0200 Subject: [PATCH] hpsa: fix warning with smp_processor_id() in preemptible section Signed-off-by: John Kacur On a 3.6-rt (real-time patch) kernel we are seeing the following BUG However, it appears to be relevant for non-realtime (mainline) as well. [ 49.688847] hpsa :03:00.0: hpsa0: <0x323a> at IRQ 67 using DAC [ 49.749928] scsi0 : hpsa [ 49.784437] BUG: using smp_processor_id() in preemptible [ ] code: kworker/u:0/6 [ 49.784465] caller is enqueue_cmd_and_start_io+0x5a/0x100 [hpsa] [ 49.784468] Pid: 6, comm: kworker/u:0 Not tainted 3.6.11.5-rt37.52.el6rt.x86_64.debug #1 [ 49.784471] Call Trace: [ 49.784512] [] debug_smp_processor_id+0x123/0x150 [ 49.784520] [] enqueue_cmd_and_start_io+0x5a/0x100 [hpsa] [ 49.784529] [] hpsa_scsi_do_simple_cmd_core+0xeb/0x110 [hpsa] [ 49.784537] [] ? swiotlb_dma_mapping_error+0x18/0x30 [ 49.784544] [] ? swiotlb_dma_mapping_error+0x18/0x30 [ 49.784553] [] hpsa_scsi_do_simple_cmd_with_retry+0x91/0x280 [hpsa] [ 49.784562] [] hpsa_scsi_do_report_luns.clone.2+0xd8/0x130 [hpsa] [ 49.784571] [] hpsa_gather_lun_info.clone.3+0x3a/0x1a0 [hpsa] [ 49.784580] [] hpsa_update_scsi_devices+0x11f/0x4f0 [hpsa] [ 49.784592] [] ? sub_preempt_count+0xa9/0xe0 [ 49.784601] [] hpsa_scan_start+0xfd/0x150 [hpsa] [ 49.784613] [] ? rt_spin_lock_slowunlock+0x78/0x90 [ 49.784626] [] do_scsi_scan_host+0x37/0xa0 [ 49.784632] [] do_scan_async+0x1a/0x30 [ 49.784643] [] async_run_entry_fn+0x9b/0x1d0 [ 49.784655] [] process_one_work+0x1f2/0x620 [ 49.784661] [] ? process_one_work+0x180/0x620 [ 49.784668] [] ? worker_thread+0x5e/0x3a0 [ 49.784674] [] ? async_schedule+0x20/0x20 [ 49.784681] [] worker_thread+0x133/0x3a0 [ 49.784688] [] ? manage_workers+0x190/0x190 [ 49.784696] [] kthread+0xa6/0xb0 [ 49.784707] [] kernel_thread_helper+0x4/0x10 [ 49.784715] [] ? finish_task_switch+0x8c/0x110 [ 49.784721] [] ? _raw_spin_unlock_irq+0x3b/0x70 [ 49.784727] [] ? retint_restore_args+0xe/0xe [ 49.784734] [] ? kthreadd+0x1e0/0x1e0 [ 49.784739] [] ? gs_change+0xb/0xb --- This is caused by enqueue_cmd_and_start_io()-> set_performant_mode()-> smp_processor_id() Which if you have debugging enabled calls debug_processor_id() and triggers the warning. The code here is c->Header.ReplyQueue = smp_processor_id() % h->nreply_queues; Since it is not critical that the code complete on the same processor, but the cpu is a hint used in generating the ReplyQueue and will still work if the cpu migrates or is preempted, it is safe to use the raw_smp_processor_id() to surpress the false positve warning. Signed-off-by: John Kacur Acked-by: Stephen --- drivers/scsi/hpsa.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c index 7f4f790..4e19267 100644 --- a/drivers/scsi/hpsa.c +++ b/drivers/scsi/hpsa.c @@ -583,7 +583,7 @@ static void set_performant_mode(struct ctlr_info *h, struct CommandList *c) c->busaddr |= 1 | (h->blockFetchTable[c->Header.SGList] << 1); if (likely(h->msix_vector)) c->Header.ReplyQueue = - smp_processor_id() % h->nreply_queues; + raw_smp_processor_id() % h->nreply_queues; } } -- 1.7.11.7 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH] hpsa: fix warning with smp_processor_id() in preemptible
From 4c01ac362210c38cdbaddd0a75c24c7070e77dfa Mon Sep 17 00:00:00 2001 From: John Kacur jka...@redhat.com Date: Fri, 26 Jul 2013 16:06:18 +0200 Subject: [PATCH] hpsa: fix warning with smp_processor_id() in preemptible section Signed-off-by: John Kacur jka...@redhat.com On a 3.6-rt (real-time patch) kernel we are seeing the following BUG However, it appears to be relevant for non-realtime (mainline) as well. [ 49.688847] hpsa :03:00.0: hpsa0: 0x323a at IRQ 67 using DAC [ 49.749928] scsi0 : hpsa [ 49.784437] BUG: using smp_processor_id() in preemptible [ ] code: kworker/u:0/6 [ 49.784465] caller is enqueue_cmd_and_start_io+0x5a/0x100 [hpsa] [ 49.784468] Pid: 6, comm: kworker/u:0 Not tainted 3.6.11.5-rt37.52.el6rt.x86_64.debug #1 [ 49.784471] Call Trace: [ 49.784512] [812abe83] debug_smp_processor_id+0x123/0x150 [ 49.784520] [a009043a] enqueue_cmd_and_start_io+0x5a/0x100 [hpsa] [ 49.784529] [a00905cb] hpsa_scsi_do_simple_cmd_core+0xeb/0x110 [hpsa] [ 49.784537] [812b09c8] ? swiotlb_dma_mapping_error+0x18/0x30 [ 49.784544] [812b09c8] ? swiotlb_dma_mapping_error+0x18/0x30 [ 49.784553] [a0090701] hpsa_scsi_do_simple_cmd_with_retry+0x91/0x280 [hpsa] [ 49.784562] [a0093558] hpsa_scsi_do_report_luns.clone.2+0xd8/0x130 [hpsa] [ 49.784571] [a00935ea] hpsa_gather_lun_info.clone.3+0x3a/0x1a0 [hpsa] [ 49.784580] [a00963df] hpsa_update_scsi_devices+0x11f/0x4f0 [hpsa] [ 49.784592] [81592019] ? sub_preempt_count+0xa9/0xe0 [ 49.784601] [a00968ad] hpsa_scan_start+0xfd/0x150 [hpsa] [ 49.784613] [8158cba8] ? rt_spin_lock_slowunlock+0x78/0x90 [ 49.784626] [813b04d7] do_scsi_scan_host+0x37/0xa0 [ 49.784632] [813b05da] do_scan_async+0x1a/0x30 [ 49.784643] [8107c4ab] async_run_entry_fn+0x9b/0x1d0 [ 49.784655] [8106ae92] process_one_work+0x1f2/0x620 [ 49.784661] [8106ae20] ? process_one_work+0x180/0x620 [ 49.784668] [8106d4fe] ? worker_thread+0x5e/0x3a0 [ 49.784674] [8107c410] ? async_schedule+0x20/0x20 [ 49.784681] [8106d5d3] worker_thread+0x133/0x3a0 [ 49.784688] [8106d4a0] ? manage_workers+0x190/0x190 [ 49.784696] [81073236] kthread+0xa6/0xb0 [ 49.784707] [815970a4] kernel_thread_helper+0x4/0x10 [ 49.784715] [81082a7c] ? finish_task_switch+0x8c/0x110 [ 49.784721] [8158e44b] ? _raw_spin_unlock_irq+0x3b/0x70 [ 49.784727] [8158e85d] ? retint_restore_args+0xe/0xe [ 49.784734] [81073190] ? kthreadd+0x1e0/0x1e0 [ 49.784739] [815970a0] ? gs_change+0xb/0xb --- This is caused by enqueue_cmd_and_start_io()- set_performant_mode()- smp_processor_id() Which if you have debugging enabled calls debug_processor_id() and triggers the warning. The code here is c-Header.ReplyQueue = smp_processor_id() % h-nreply_queues; Since it is not critical that the code complete on the same processor, but the cpu is a hint used in generating the ReplyQueue and will still work if the cpu migrates or is preempted, it is safe to use the raw_smp_processor_id() to surpress the false positve warning. Signed-off-by: John Kacur jka...@redhat.com Acked-by: Stephen scame...@beardog.cce.hp.com --- drivers/scsi/hpsa.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c index 7f4f790..4e19267 100644 --- a/drivers/scsi/hpsa.c +++ b/drivers/scsi/hpsa.c @@ -583,7 +583,7 @@ static void set_performant_mode(struct ctlr_info *h, struct CommandList *c) c-busaddr |= 1 | (h-blockFetchTable[c-Header.SGList] 1); if (likely(h-msix_vector)) c-Header.ReplyQueue = - smp_processor_id() % h-nreply_queues; + raw_smp_processor_id() % h-nreply_queues; } } -- 1.7.11.7 -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
