Messages in this thread | | | Date | Tue, 05 Jan 2021 22:03:59 +0100 | From | Michael Walle <> | Subject | Re: [PATCH v2 16/17] driver core: Refactor fw_devlink feature |
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Am 2021-01-05 20:00, schrieb Saravana Kannan: > On Mon, Dec 28, 2020 at 7:35 PM Michael Walle <michael@walle.cc> wrote: >> >> > The current implementation of fw_devlink is very inefficient because it >> > tries to get away without creating fwnode links in the name of saving >> > memory usage. Past attempts to optimize runtime at the cost of memory >> > usage were blocked with request for data showing that the optimization >> > made significant improvement for real world scenarios. >> > >> > We have those scenarios now. There have been several reports of boot >> > time increase in the order of seconds in this thread [1]. Several OEMs >> > and SoC manufacturers have also privately reported significant >> > (350-400ms) increase in boot time due to all the parsing done by >> > fw_devlink. >> > >> > So this patch uses all the setup done by the previous patches in this >> > series to refactor fw_devlink to be more efficient. Most of the code has >> > been moved out of firmware specific (DT mostly) code into driver core. >> > >> > This brings the following benefits: >> > - Instead of parsing the device tree multiple times during bootup, >> > fw_devlink parses each fwnode node/property only once and creates >> > fwnode links. The rest of the fw_devlink code then just looks at these >> > fwnode links to do rest of the work. >> > >> > - Makes it much easier to debug probe issue due to fw_devlink in the >> > future. fw_devlink=on blocks the probing of devices if they depend on >> > a device that hasn't been added yet. With this refactor, it'll be very >> > easy to tell what that device is because we now have a reference to >> > the fwnode of the device. >> > >> > - Much easier to add fw_devlink support to ACPI and other firmware >> > types. A refactor to move the common bits from DT specific code to >> > driver core was in my TODO list as a prerequisite to adding ACPI >> > support to fw_devlink. This series gets that done. >> > >> > [1] - https://lore.kernel.org/linux-omap/ea02f57e-871d-cd16-4418-c1da4bbc4696@ti.com/ >> > Signed-off-by: Saravana Kannan <saravanak@google.com> >> > Tested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> >> > Tested-by: Grygorii Strashko <grygorii.strashko@ti.com> >> >> git bisect show that this commit broke my board in 5.11-rc1: >> >> [ 2.294375] sysfs: cannot create duplicate filename >> '/devices/virtual/devlink/0000:00:00.1--0000:00:00.1' >> [ 2.303999] CPU: 1 PID: 1 Comm: swapper/0 Not tainted >> 5.11.0-rc1-00016-ga0fb284b267 #267 >> [ 2.312125] Hardware name: Kontron SMARC-sAL28 (4 Lane) (DT) >> [ 2.317804] Call trace: >> [ 2.320253] dump_backtrace+0x0/0x1b8 >> [ 2.323936] show_stack+0x20/0x70 >> [ 2.327263] dump_stack+0xd8/0x134 >> [ 2.330677] sysfs_warn_dup+0x6c/0x88 >> [ 2.334351] sysfs_create_dir_ns+0xe8/0x100 >> [ 2.338547] kobject_add_internal+0x9c/0x290 >> [ 2.342833] kobject_add+0xa0/0x108 >> [ 2.346331] device_add+0xfc/0x798 >> [ 2.349746] device_link_add+0x454/0x5e0 >> [ 2.353682] fw_devlink_create_devlink+0xb8/0xc8 >> [ 2.358316] __fw_devlink_link_to_suppliers+0x84/0x180 >> [ 2.363474] __fw_devlink_link_to_suppliers+0x134/0x180 >> [ 2.368718] device_add+0x778/0x798 >> [ 2.372217] device_register+0x28/0x38 >> [ 2.375979] __mdiobus_register+0x94/0x340 >> [ 2.380089] of_mdiobus_register+0xb4/0x380 >> [ 2.384285] enetc_pf_probe+0x73c/0xb10 >> [ 2.388132] local_pci_probe+0x48/0xb8 >> [ 2.391896] pci_device_probe+0x120/0x1c0 >> [ 2.395920] really_probe+0xec/0x3c0 >> [ 2.399505] driver_probe_device+0x60/0xc0 >> [ 2.403614] device_driver_attach+0x7c/0x88 >> [ 2.407810] __driver_attach+0x60/0xe8 >> [ 2.411570] bus_for_each_dev+0x7c/0xd0 >> [ 2.415419] driver_attach+0x2c/0x38 >> [ 2.419004] bus_add_driver+0x194/0x1f8 >> [ 2.422851] driver_register+0x6c/0x128 >> [ 2.426698] __pci_register_driver+0x4c/0x58 >> [ 2.430983] enetc_pf_driver_init+0x2c/0x38 >> [ 2.435181] do_one_initcall+0x54/0x2d8 >> [ 2.439029] kernel_init_freeable+0x1fc/0x268 >> [ 2.443403] kernel_init+0x1c/0x120 >> [ 2.446904] ret_from_fork+0x10/0x30 >> [ 2.450502] kobject_add_internal failed for >> 0000:00:00.1--0000:00:00.1 with -EEXIST, don't try to register things >> with the same name in the same directory. >> >> Looks like it will generate that link twice? Let me know if I can help >> testing. >> >> See also: https://lavalab.kontron.com/scheduler/job/3894#L831 > > I'll look into this this week. Is the DT for this board in upstream? > If so, can you point me to the DT file(s)?
arch/arm64/boot/dts/freescale/fsl-ls1028a-kontron-kbox-a-230-ls.dts
> Also, can you give me the output of this? > find /sys/devices -type d | grep "0000:00:00.1"
# uname -a Linux buildroot 5.11.0-rc1-next-20210104 #298 SMP PREEMPT Tue Jan 5 21:55:23 CET 2021 aarch64 GNU/Linux # find /sys/devices -type d | grep "0000:00:00.1" /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1 /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/power /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/net /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/net/eno1 /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/net/eno1/statistics /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/net/eno1/power /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/net/eno1/queues /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/net/eno1/queues/tx-6 /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/net/eno1/queues/tx-6/byte_queue_limits /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/net/eno1/queues/tx-4 /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/net/eno1/queues/tx-4/byte_queue_limits /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/net/eno1/queues/rx-7 /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/net/eno1/queues/tx-2 /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/net/eno1/queues/tx-2/byte_queue_limits /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/net/eno1/queues/rx-5 /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/net/eno1/queues/tx-0 /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/net/eno1/queues/tx-0/byte_queue_limits /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/net/eno1/queues/rx-3 /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/net/eno1/queues/rx-1 /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/net/eno1/queues/tx-7 /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/net/eno1/queues/tx-7/byte_queue_limits /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/net/eno1/queues/tx-5 /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/net/eno1/queues/tx-5/byte_queue_limits /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/net/eno1/queues/tx-3 /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/net/eno1/queues/tx-3/byte_queue_limits /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/net/eno1/queues/rx-6 /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/net/eno1/queues/tx-1 /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/net/eno1/queues/tx-1/byte_queue_limits /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/net/eno1/queues/rx-4 /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/net/eno1/queues/rx-2 /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/net/eno1/queues/rx-0 /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/mdio_bus /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/mdio_bus/0000:00:00.1 /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/mdio_bus/0000:00:00.1/statistics /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/mdio_bus/0000:00:00.1/power /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/mdio_bus/0000:00:00.1/0000:00:00.1:04 /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/mdio_bus/0000:00:00.1/0000:00:00.1:04/statistics /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/mdio_bus/0000:00:00.1/0000:00:00.1:04/regulator /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/mdio_bus/0000:00:00.1/0000:00:00.1:04/regulator/regulator.3 /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/mdio_bus/0000:00:00.1/0000:00:00.1:04/regulator/regulator.3/power /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/mdio_bus/0000:00:00.1/0000:00:00.1:04/regulator/regulator.4 /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/mdio_bus/0000:00:00.1/0000:00:00.1:04/regulator/regulator.4/power /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/mdio_bus/0000:00:00.1/0000:00:00.1:04/power /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/msi_irqs /sys/devices/platform/soc/1f0000000.pcie/pci0000:00/0000:00:00.1/link /sys/devices/virtual/devlink/5000000.iommu--0000:00:00.1
HTH, -michael
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