From: Michael Walle <michael@walle.cc>
To: Saravana Kannan <saravanak@google.com>
Cc: Ard Biesheuvel <ardb@kernel.org>,
"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
<devicetree@vger.kernel.org>,
Frank Rowand <frowand.list@gmail.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Grygorii Strashko <grygorii.strashko@ti.com>,
Android Kernel Team <kernel-team@android.com>,
Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
Len Brown <lenb@kernel.org>,
ACPI Devel Maling List <linux-acpi@vger.kernel.org>,
linux-efi <linux-efi@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Marc Zyngier <maz@kernel.org>,
"Rafael J. Wysocki" <rafael@kernel.org>,
"Rafael J. Wysocki" <rjw@rjwysocki.net>,
Rob Herring <robh+dt@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Tomi Valkeinen <tomi.valkeinen@ti.com>
Subject: Re: [PATCH v2 16/17] driver core: Refactor fw_devlink feature
Date: Tue, 05 Jan 2021 22:03:59 +0100 [thread overview]
Message-ID: <6d5914f095556119f4a38def9297accd@walle.cc> (raw)
In-Reply-To: <CAGETcx8BNkvz=F7Z6HGRZyEcPcQGyJ1hneVMZ=mOeJ8hdbGt1A@mail.gmail.com>
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
next prev parent reply other threads:[~2021-01-05 21:05 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-21 2:02 [PATCH v2 00/17] Refactor fw_devlink to significantly improve boot time Saravana Kannan
2020-11-21 2:02 ` [PATCH v2 01/17] Revert "driver core: Avoid deferred probe due to fw_devlink_pause/resume()" Saravana Kannan
2020-11-21 2:02 ` [PATCH v2 02/17] Revert "driver core: Rename dev_links_info.defer_sync to defer_hook" Saravana Kannan
2020-11-21 2:02 ` [PATCH v2 03/17] Revert "driver core: Don't do deferred probe in parallel with kernel_init thread" Saravana Kannan
2020-11-21 2:02 ` [PATCH v2 04/17] Revert "driver core: Remove check in driver_deferred_probe_force_trigger()" Saravana Kannan
2020-11-21 2:02 ` [PATCH v2 05/17] Revert "of: platform: Batch fwnode parsing when adding all top level devices" Saravana Kannan
2020-12-07 22:18 ` Rob Herring
2020-11-21 2:02 ` [PATCH v2 06/17] Revert "driver core: fw_devlink: Add support for batching fwnode parsing" Saravana Kannan
2020-11-21 2:02 ` [PATCH v2 07/17] driver core: Add fwnode_init() Saravana Kannan
2020-12-06 7:26 ` Leon Romanovsky
2020-12-07 19:25 ` Saravana Kannan
2020-12-07 19:53 ` Leon Romanovsky
2020-12-07 20:36 ` Saravana Kannan
2020-12-08 6:34 ` Leon Romanovsky
2020-12-07 22:20 ` Rob Herring
2020-11-21 2:02 ` [PATCH v2 08/17] driver core: Add fwnode link support Saravana Kannan
2020-12-06 7:48 ` Leon Romanovsky
2020-12-07 19:25 ` Saravana Kannan
2020-12-07 19:56 ` Leon Romanovsky
2020-12-07 22:21 ` Rob Herring
2020-11-21 2:02 ` [PATCH v2 09/17] driver core: Allow only unprobed consumers for SYNC_STATE_ONLY device links Saravana Kannan
2020-11-21 2:02 ` [PATCH v2 10/17] device property: Add fwnode_is_ancestor_of() and fwnode_get_next_parent_dev() Saravana Kannan
2020-11-21 2:02 ` [PATCH v2 11/17] driver core: Redefine the meaning of fwnode_operations.add_links() Saravana Kannan
2020-11-21 2:02 ` [PATCH v2 12/17] driver core: Add fw_devlink_parse_fwtree() Saravana Kannan
2020-11-21 2:02 ` [PATCH v2 13/17] driver core: Use device's fwnode to check if it is waiting for suppliers Saravana Kannan
2022-06-27 11:42 ` Abel Vesa
2022-06-27 22:30 ` Saravana Kannan
2022-06-28 15:24 ` Abel Vesa
2022-06-28 15:44 ` Abel Vesa
2022-06-28 15:55 ` Abel Vesa
2022-06-28 18:09 ` Saravana Kannan
2023-01-05 14:47 ` Dmitry Baryshkov
2020-11-21 2:02 ` [PATCH v2 14/17] of: property: Update implementation of add_links() to create fwnode links Saravana Kannan
2020-12-07 22:37 ` Rob Herring
2020-11-21 2:02 ` [PATCH v2 15/17] efi: " Saravana Kannan
2020-11-21 2:02 ` [PATCH v2 16/17] driver core: Refactor fw_devlink feature Saravana Kannan
2020-11-23 16:00 ` [driver core] 95f755a4ef: will-it-scale.per_process_ops 2.2% improvement kernel test robot
2020-12-11 14:11 ` [PATCH v2 16/17] driver core: Refactor fw_devlink feature Qian Cai
2020-12-11 16:34 ` Robin Murphy
2020-12-11 17:51 ` Saravana Kannan
2020-12-11 18:03 ` Marc Zyngier
2020-12-11 18:20 ` Saravana Kannan
2020-12-11 19:07 ` Marc Zyngier
2020-12-11 22:29 ` Saravana Kannan
2020-12-29 3:34 ` Michael Walle
2021-01-05 19:00 ` Saravana Kannan
2021-01-05 21:03 ` Michael Walle [this message]
2021-01-06 23:29 ` Saravana Kannan
2020-11-21 2:02 ` [PATCH v2 17/17] driver core: Delete pointless parameter in fwnode_operations.add_links Saravana Kannan
2020-12-07 22:38 ` Rob Herring
2020-11-24 8:29 ` [PATCH v2 00/17] Refactor fw_devlink to significantly improve boot time Tomi Valkeinen
2020-11-24 17:25 ` Saravana Kannan
2020-12-03 19:05 ` Saravana Kannan
2020-12-09 18:16 ` Greg Kroah-Hartman
2020-12-09 20:24 ` Saravana Kannan
2020-12-10 9:26 ` Greg Kroah-Hartman
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