pci: Annotate PCI quirks in initcall_debug style

PATCH Arjan van de Ven 2 participants 2 messages Jan 31, 2012 – Feb 10, 2012 PCI

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Arjan van de Ven

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2012-01-31 04:50 UTC #0 lore raw

Quoted 1 line

From 77fcc610189853f9c8cf35f77bb8bcfc68833202 Mon Sep 17 00:00:00 2001

From: Arjan van de Ven <[email protected]>
Date: Mon, 30 Jan 2012 20:30:03 -0800
Subject: [PATCH] pci: Annotate PCI quirks in initcall_debug style

While diagnosing some boot time issues on a platform, all that I could see in the bootgraph/dmesg was that the system was spending a lot of time in applying one or more PCI quirks... which was virtually undebuggable.

This patch adds printk's in "initcall_debug" style to the dmesg, which are added when the user asks for the initcall_debug (the nr one tool to use when debugging boot hangs or boot time issues) kernel command line option.

CC Jesse Barnes <[email protected]>

CC [email protected]

Signed-off-by Arjan van de Ven <[email protected]>

---
 drivers/pci/quirks.c |   21 ++++++++++++++++++++-
 1 files changed, 20 insertions(+), 1 deletions(-)

drivers/pci/quirks.c +20 -1

index 6476547..b3afa1c 100644
@@ -2906,6 +2906,22 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x65f8, quirk_intel_mc_errata);
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x65f9, quirk_intel_mc_errata);
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x65fa, quirk_intel_mc_errata);
 
+
+static void do_one_fixup_debug(void (*fn)(struct pci_dev *dev), struct pci_dev *dev)
+{
+	ktime_t calltime, delta, rettime;
+	unsigned long long duration;
+
+	printk(KERN_DEBUG "calling  %pF @ %i\n", fn, task_pid_nr(current));
+	calltime = ktime_get();
+	fn(dev);
+	rettime = ktime_get();
+	delta = ktime_sub(rettime, calltime);
+	duration = (unsigned long long) ktime_to_ns(delta) >> 10;
+	printk(KERN_DEBUG "pci fixup %pF returned after %lld usecs\n", fn,
+		duration);
+}
+
 static void pci_do_fixups(struct pci_dev *dev, struct pci_fixup *f,
 			  struct pci_fixup *end)
 {

@@ -2913,7 +2929,10 @@ static void pci_do_fixups(struct pci_dev *dev, struct pci_fixup *f,
 		if ((f->vendor == dev->vendor || f->vendor == (u16) PCI_ANY_ID) &&
 		    (f->device == dev->device || f->device == (u16) PCI_ANY_ID)) {
 			dev_dbg(&dev->dev, "calling %pF\n", f->hook);
-			f->hook(dev);
+			if (initcall_debug)
+				do_one_fixup_debug(f->hook, dev);
+			else
+				f->hook(dev);
 		}
 		f++;
 	}

Signature · 8 lines

1.7.6.4



-- 
Arjan van de Ven 	Intel Open Source Technology Centre
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visit http://www.lesswatts.org

Jesse Barnes

2012-02-10 19:42 UTC #1 lore raw

Quoted 52 lines · On Mon, 30 Jan 2012 20:52:07 -0800 Arjan van de Ven <[email protected]> wrote:

From 77fcc610189853f9c8cf35f77bb8bcfc68833202 Mon Sep 17 00:00:00 2001
From: Arjan van de Ven <[email protected]>
Date: Mon, 30 Jan 2012 20:30:03 -0800
Subject: [PATCH] pci: Annotate PCI quirks in initcall_debug style
While diagnosing some boot time issues on a platform, all that I could see in the bootgraph/dmesg was that the system was spending a lot of time in applying one or more PCI quirks... which was virtually undebuggable.
This patch adds printk's in "initcall_debug" style to the dmesg, which are added when the user asks for the initcall_debug (the nr one tool to use when debugging boot hangs or boot time issues) kernel command line option.
CC Jesse Barnes <[email protected]>
CC [email protected]
Signed-off-by Arjan van de Ven <[email protected]>
---
 drivers/pci/quirks.c |   21 ++++++++++++++++++++-
 1 files changed, 20 insertions(+), 1 deletions(-)
drivers/pci/quirks.c +16 -0
index 6476547..b3afa1c 100644
@@ -2906,6 +2906,22 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x65f8, quirk_intel_mc_errata);
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x65f9, quirk_intel_mc_errata);
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x65fa, quirk_intel_mc_errata);
 
+
+static void do_one_fixup_debug(void (*fn)(struct pci_dev *dev), struct pci_dev *dev)
+{
+	ktime_t calltime, delta, rettime;
+	unsigned long long duration;
+
+	printk(KERN_DEBUG "calling  %pF @ %i\n", fn, task_pid_nr(current));
+	calltime = ktime_get();
+	fn(dev);
+	rettime = ktime_get();
+	delta = ktime_sub(rettime, calltime);
+	duration = (unsigned long long) ktime_to_ns(delta) >> 10;
+	printk(KERN_DEBUG "pci fixup %pF returned after %lld usecs\n", fn,
+		duration);
+}
+
 static void pci_do_fixups(struct pci_dev *dev, struct pci_fixup *f,
 			  struct pci_fixup *end)
 {
@@ -2913,7 +2929,10 @@ static void pci_do_fixups(struct pci_dev *dev, struct pci_fixup *f,
 		if ((f->vendor == dev->vendor || f->vendor == (u16) PCI_ANY_ID) &&

drivers/pci/quirks.c static void pci_do_fixups(struct pci_dev *dev, struct pci_fixup *f, · line 2938

Quoted 10 lines

drivers/pci/quirks.c +4 -1

 		    (f->device == dev->device || f->device == (u16) PCI_ANY_ID)) {
 			dev_dbg(&dev->dev, "calling %pF\n", f->hook);
-			f->hook(dev);
+			if (initcall_debug)
+				do_one_fixup_debug(f->hook, dev);
+			else
+				f->hook(dev);
 		}
 		f++;
 	}

Looks cool Arjan, thanks. Applied to my -next branch.

Signature · 1 line

Jesse Barnes, Intel Open Source Technology Center