Re: Linux 5.15-rc1

From: Heiner Kallweit
Date: Tue Sep 14 2021 - 02:22:03 EST

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In reply to: Dave Jones: "Re: Linux 5.15-rc1"
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On 14.09.2021 01:46, Bjorn Helgaas wrote:
> On Mon, Sep 13, 2021 at 10:18:18AM -0400, Dave Jones wrote:
>> On Sun, Sep 12, 2021 at 04:58:27PM -0700, Linus Torvalds wrote:
>> > So 5.15 isn't shaping up to be a particularly large release, at least
>> > in number of commits. At only just over 10k non-merge commits, this is
>> > in fact the smallest rc1 we have had in the 5.x series. We're usually
>> > hovering in the 12-14k commit range.
>>
>> This release takes over two minutes longer to boot on one my
>> machines than 5.14. The time just seems to be unaccounted for, even
>> with initcall_debug
>
>> ...
>> [ 2.194093] pci 0000:01:00.0: calling quirk_f0_vpd_link+0x0/0x60 @ 1
>> [ 2.194097] pci 0000:01:00.0: quirk_f0_vpd_link+0x0/0x60 took 0 usecs
>> [ 2.194100] pci 0000:01:00.0: [8086:10fb] type 00 class 0x020000
>> [ 2.194109] pci 0000:01:00.0: reg 0x10: [mem 0xd0080000-0xd00fffff 64bit pref]
>> [ 2.194113] pci 0000:01:00.0: reg 0x18: [io 0xe020-0xe03f]
>> [ 2.194121] pci 0000:01:00.0: reg 0x20: [mem 0xd0104000-0xd0107fff 64bit pref]
>> [ 2.194126] pci 0000:01:00.0: reg 0x30: [mem 0xdfd80000-0xdfdfffff pref]
>> [ 2.194136] pci 0000:01:00.0: calling quirk_igfx_skip_te_disable+0x0/0x50 @ 1
>> [ 2.194139] pci 0000:01:00.0: quirk_igfx_skip_te_disable+0x0/0x50 took 0 usecs
>> [ 2.194164] pci 0000:01:00.0: PME# supported from D0 D3hot D3cold
>>
>> * stall here for 86 seconds *
>>
>> [ 88.675114] pci 0000:01:00.0: reg 0x184: [mem 0x00000000-0x00003fff 64bit pref]
>> ...
>
>
>> 7bac54497c3e3b2ca37b7043f1fa78586540f10e is the first bad commit
>> commit 7bac54497c3e3b2ca37b7043f1fa78586540f10e
>> Author: Heiner Kallweit <hkallweit1@xxxxxxxxx>
>> Date: Sun Aug 8 19:22:52 2021 +0200
>>
>> PCI/VPD: Determine VPD size in pci_vpd_init()
>>
>> Determine VPD size in pci_vpd_init().
>>
>> Quirks set dev->vpd.len to a non-zero value, so they cause us to skip the
>> dynamic size calculation. Prerequisite is that we move the quirks from
>> FINAL to HEADER so they are run before pci_vpd_init().
>>
>> Link: https://lore.kernel.org/r/cc4a6538-557a-294d-4f94-e6d1d3c91589@xxxxxxxxx
>> Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx>
>> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
>>
>>
>> Which unfortunately doesn't revert cleanly I can't test it reverted in
>> isolation.
>>
>> My guess is there's something quirky about the PCI bus on this machine
>> that causes stalls until we hit timeout, but I'm not sure where to begin
>> debugging this.
>
> Sorry for the inconvenience of this, and thank you very much for doing
> the bisection to track it down.
>
> We *could* revert 7bac54497c3e, but it'd be messy because a bunch of
> follow-up stuff depends on it.
>
> I propose something like the patch below. Would you mind trying it
> out?
>
>
> commit 4ede9949b93c ("PCI/VPD: Defer VPD sizing until first access")
> Author: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> Date: Mon Sep 13 16:13:26 2021 -0500
>
> PCI/VPD: Defer VPD sizing until first access
>
> 7bac54497c3e ("PCI/VPD: Determine VPD size in pci_vpd_init()") reads VPD at
> enumeration-time to find the size. But this is quite slow, and we don't
> need the size until we actually need data from VPD. Dave reported a boot
> slowdown of more than two minutes [1].
>
> Defer the VPD sizing until a driver or the user requests information from
> VPD. If devices are quirked because VPD is known not to work, clear the
> vpd.cap pointer so we don't access it at all.
>
> [1] https://lore.kernel.org/r/20210913141818.GA27911@xxxxxxxxxxxxxxxxx/
> Fixes: 7bac54497c3e ("PCI/VPD: Determine VPD size in pci_vpd_init()")
> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
>
> diff --git a/drivers/pci/vpd.c b/drivers/pci/vpd.c
> index 25557b272a4f..ca823ceee10c 100644
> --- a/drivers/pci/vpd.c
> +++ b/drivers/pci/vpd.c
> @@ -46,13 +46,12 @@ static struct pci_dev *pci_get_func0_dev(struct pci_dev *dev)
> }
>
> #define PCI_VPD_MAX_SIZE (PCI_VPD_ADDR_MASK + 1)
> -#define PCI_VPD_SZ_INVALID UINT_MAX
>
> /**
> * pci_vpd_size - determine actual size of Vital Product Data
> * @dev: pci device struct
> */
> -static size_t pci_vpd_size(struct pci_dev *dev)
> +static void pci_vpd_size(struct pci_dev *dev)
> {
> size_t off = 0, size;
> unsigned char tag, header[1+2]; /* 1 byte tag, 2 bytes length */
> @@ -71,7 +70,7 @@ static size_t pci_vpd_size(struct pci_dev *dev)
> if (pci_read_vpd(dev, off + 1, 2, &header[1]) != 2) {
> pci_warn(dev, "failed VPD read at offset %zu\n",
> off + 1);
> - return off ?: PCI_VPD_SZ_INVALID;
> + goto finish;
> }
> size = pci_vpd_lrdt_size(header);
> if (off + size > PCI_VPD_MAX_SIZE)
> @@ -87,16 +86,19 @@ static size_t pci_vpd_size(struct pci_dev *dev)
>
> off += PCI_VPD_SRDT_TAG_SIZE + size;
> if (tag == PCI_VPD_STIN_END) /* End tag descriptor */
> - return off;
> + goto finish;
> }
> }
> - return off;
> + goto finish;
>
> error:
> pci_info(dev, "invalid VPD tag %#04x (size %zu) at offset %zu%s\n",
> header[0], size, off, off == 0 ?
> "; assume missing optional EEPROM" : "");
> - return off ?: PCI_VPD_SZ_INVALID;
> +finish:
> + dev->vpd.len = off;
> + if (off == 0)
> + dev->vpd.cap = 0; /* No VPD at all */
> }
>
> /*
> @@ -145,9 +147,6 @@ static ssize_t pci_vpd_read(struct pci_dev *dev, loff_t pos, size_t count,
> loff_t end = pos + count;
> u8 *buf = arg;
>
> - if (!vpd->cap)
> - return -ENODEV;
> -
> if (pos < 0)
> return -EINVAL;
>
> @@ -206,9 +205,6 @@ static ssize_t pci_vpd_write(struct pci_dev *dev, loff_t pos, size_t count,
> loff_t end = pos + count;
> int ret = 0;
>
> - if (!vpd->cap)
> - return -ENODEV;
> -
> if (pos < 0 || (pos & 3) || (count & 3))
> return -EINVAL;
>
> @@ -244,12 +240,6 @@ void pci_vpd_init(struct pci_dev *dev)
> {
> dev->vpd.cap = pci_find_capability(dev, PCI_CAP_ID_VPD);
> mutex_init(&dev->vpd.lock);
> -
> - if (!dev->vpd.len)
> - dev->vpd.len = pci_vpd_size(dev);
> -
> - if (dev->vpd.len == PCI_VPD_SZ_INVALID)
> - dev->vpd.cap = 0;
> }
>
> static ssize_t vpd_read(struct file *filp, struct kobject *kobj,
> @@ -294,25 +284,29 @@ const struct attribute_group pci_dev_vpd_attr_group = {
>
> void *pci_vpd_alloc(struct pci_dev *dev, unsigned int *size)
> {
> - unsigned int len = dev->vpd.len;
> + struct pci_vpd *vpd = &dev->vpd;
> + unsigned int len;
> void *buf;
> int cnt;
>
> - if (!dev->vpd.cap)
> + if (!vpd->cap)
> return ERR_PTR(-ENODEV);
>
> buf = kmalloc(len, GFP_KERNEL);
> if (!buf)
> return ERR_PTR(-ENOMEM);
>
> - cnt = pci_read_vpd(dev, 0, len, buf);
> + if (vpd->len == 0)
> + pci_vpd_size(dev);
> +
> + cnt = pci_read_vpd(dev, 0, vpd->len, buf);
> if (cnt != len) {
> kfree(buf);
> return ERR_PTR(-EIO);
> }
>
> if (size)
> - *size = len;
> + *size = vpd->len;
>
> return buf;
> }
> @@ -374,6 +368,7 @@ static int pci_vpd_find_info_keyword(const u8 *buf, unsigned int off,
> */
> ssize_t pci_read_vpd(struct pci_dev *dev, loff_t pos, size_t count, void *buf)
> {
> + struct pci_vpd *vpd;
> ssize_t ret;
>
> if (dev->dev_flags & PCI_DEV_FLAGS_VPD_REF_F0) {
> @@ -381,11 +376,27 @@ ssize_t pci_read_vpd(struct pci_dev *dev, loff_t pos, size_t count, void *buf)
> if (!dev)
> return -ENODEV;
>
> + vpd = &dev->vpd;
> + if (!vpd->cap) {
> + pci_dev_put(dev);
> + return -ENODEV;
> + }
> +
> + if (vpd->len == 0)
> + pci_vpd_size(dev);
> +
> ret = pci_vpd_read(dev, pos, count, buf);
> pci_dev_put(dev);
> return ret;
> }
>
> + vpd = &dev->vpd;
> + if (!vpd->cap)
> + return -ENODEV;
> +
> + if (vpd->len == 0)
> + pci_vpd_size(dev);
> +
> return pci_vpd_read(dev, pos, count, buf);
> }
> EXPORT_SYMBOL(pci_read_vpd);
> @@ -399,6 +410,7 @@ EXPORT_SYMBOL(pci_read_vpd);
> */
> ssize_t pci_write_vpd(struct pci_dev *dev, loff_t pos, size_t count, const void *buf)
> {
> + struct pci_vpd *vpd;
> ssize_t ret;
>
> if (dev->dev_flags & PCI_DEV_FLAGS_VPD_REF_F0) {
> @@ -406,11 +418,26 @@ ssize_t pci_write_vpd(struct pci_dev *dev, loff_t pos, size_t count, const void
> if (!dev)
> return -ENODEV;
>
> + vpd = &dev->vpd;
> + if (!vpd->cap) {
> + pci_dev_put(dev);
> + return -ENODEV;
> + }
> +
> + if (vpd->len == 0)
> + pci_vpd_size(dev);
> +
> ret = pci_vpd_write(dev, pos, count, buf);
> pci_dev_put(dev);
> return ret;
> }
>
> + if (!vpd->cap)
> + return -ENODEV;
> +
> + if (vpd->len == 0)
> + pci_vpd_size(dev);
> +
> return pci_vpd_write(dev, pos, count, buf);
> }
> EXPORT_SYMBOL(pci_write_vpd);
> @@ -500,27 +527,27 @@ DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_INTEL, PCI_ANY_ID,
> */
> static void quirk_blacklist_vpd(struct pci_dev *dev)
> {
> - dev->vpd.len = PCI_VPD_SZ_INVALID;
> + dev->vpd.cap = 0;
> pci_warn(dev, FW_BUG "disabling VPD access (can't determine size of non-standard VPD format)\n");
> }
> -DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x0060, quirk_blacklist_vpd);
> -DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x007c, quirk_blacklist_vpd);
> -DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x0413, quirk_blacklist_vpd);
> -DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x0078, quirk_blacklist_vpd);
> -DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x0079, quirk_blacklist_vpd);
> -DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x0073, quirk_blacklist_vpd);
> -DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x0071, quirk_blacklist_vpd);
> -DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x005b, quirk_blacklist_vpd);
> -DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x002f, quirk_blacklist_vpd);
> -DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x005d, quirk_blacklist_vpd);
> -DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x005f, quirk_blacklist_vpd);
> -DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATTANSIC, PCI_ANY_ID, quirk_blacklist_vpd);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x0060, quirk_blacklist_vpd);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x007c, quirk_blacklist_vpd);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x0413, quirk_blacklist_vpd);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x0078, quirk_blacklist_vpd);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x0079, quirk_blacklist_vpd);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x0073, quirk_blacklist_vpd);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x0071, quirk_blacklist_vpd);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x005b, quirk_blacklist_vpd);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x002f, quirk_blacklist_vpd);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x005d, quirk_blacklist_vpd);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x005f, quirk_blacklist_vpd);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATTANSIC, PCI_ANY_ID, quirk_blacklist_vpd);
> /*

Leaving the quirks in FIXUP_HEADER stage would have the advantage that for
blacklisted devices the vpd sysfs attribute isn't visibale. The needed
changes to the patch are minimal.

> * The Amazon Annapurna Labs 0x0031 device id is reused for other non Root Port
> * device types, so the quirk is registered for the PCI_CLASS_BRIDGE_PCI class.
> */
> -DECLARE_PCI_FIXUP_CLASS_HEADER(PCI_VENDOR_ID_AMAZON_ANNAPURNA_LABS, 0x0031,
> - PCI_CLASS_BRIDGE_PCI, 8, quirk_blacklist_vpd);
> +DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_AMAZON_ANNAPURNA_LABS, 0x0031,
> + PCI_CLASS_BRIDGE_PCI, 8, quirk_blacklist_vpd);
>
> static void quirk_chelsio_extend_vpd(struct pci_dev *dev)
> {
> @@ -545,7 +572,7 @@ static void quirk_chelsio_extend_vpd(struct pci_dev *dev)
> dev->vpd.len = 2048;
> }
>
> -DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_CHELSIO, PCI_ANY_ID,
> - quirk_chelsio_extend_vpd);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_CHELSIO, PCI_ANY_ID,
> + quirk_chelsio_extend_vpd);
>
> #endif
>

Next message: kernel test robot: "drivers/gpio/gpio-virtio.c:23:8: warning: Excessive padding in 'struct virtio_gpio_line' (122 padding bytes, where 58 is optimal)."
Previous message: Li Fei1: "Re: [RFC PATCH v3 0/2] Introduce some interfaces for ACRN hypervisor HSM driver"
In reply to: Dave Jones: "Re: Linux 5.15-rc1"
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