From a5bde5d8fde8a8cb28e59a672d5ddc5b9c1e7656 Mon Sep 17 00:00:00 2001 From: Breno Leitao Date: Wed, 5 Aug 2026 07:52:36 -0700 Subject: workqueue: skip the node_nr_active update for non-unbound workqueues apply_wqattrs_commit() updates node_nr_active->max unconditionally. wq->node_nr_active[] is only allocated for unbound workqueues, so guard the call before per-cpu workqueues start using this path. No functional change: only unbound workqueues reach apply_wqattrs_*() today. Signed-off-by: Breno Leitao Signed-off-by: Tejun Heo --- Documentation/ABI/testing/sysfs-devices-mapping | 62 +++++++++++++++++++++++++ 1 file changed, 62 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-devices-mapping (limited to 'Documentation/ABI/testing/sysfs-devices-mapping') diff --git a/Documentation/ABI/testing/sysfs-devices-mapping b/Documentation/ABI/testing/sysfs-devices-mapping new file mode 100644 index 000000000..2eee1446a --- /dev/null +++ b/Documentation/ABI/testing/sysfs-devices-mapping @@ -0,0 +1,62 @@ +What: /sys/devices/uncore_iio_x/dieX +Date: February 2020 +Contact: Alexander Antonov +Description: + Each IIO stack (PCIe root port) has its own IIO PMON block, so + each dieX file (where X is die number) holds "Segment:Root Bus" + for PCIe root port, which can be monitored by that IIO PMON + block. + For example, on 4-die Xeon platform with up to 6 IIO stacks per + die and, therefore, 6 IIO PMON blocks per die, the mapping of + IIO PMON block 0 exposes as the following:: + + $ ls /sys/devices/uncore_iio_0/die* + -r--r--r-- /sys/devices/uncore_iio_0/die0 + -r--r--r-- /sys/devices/uncore_iio_0/die1 + -r--r--r-- /sys/devices/uncore_iio_0/die2 + -r--r--r-- /sys/devices/uncore_iio_0/die3 + + $ tail /sys/devices/uncore_iio_0/die* + ==> /sys/devices/uncore_iio_0/die0 <== + 0000:00 + ==> /sys/devices/uncore_iio_0/die1 <== + 0000:40 + ==> /sys/devices/uncore_iio_0/die2 <== + 0000:80 + ==> /sys/devices/uncore_iio_0/die3 <== + 0000:c0 + + Which means:: + + IIO PMU 0 on die 0 belongs to PCI RP on bus 0x00, domain 0x0000 + IIO PMU 0 on die 1 belongs to PCI RP on bus 0x40, domain 0x0000 + IIO PMU 0 on die 2 belongs to PCI RP on bus 0x80, domain 0x0000 + IIO PMU 0 on die 3 belongs to PCI RP on bus 0xc0, domain 0x0000 + +What: /sys/devices/uncore_upi_x/dieX +Date: March 2022 +Contact: Alexander Antonov +Description: + Each /sys/devices/uncore_upi_X/dieY file holds "upi_Z,die_W" + value that means UPI link number X on die Y is connected to UPI + link Z on die W and this link between sockets can be monitored + by UPI PMON block. + For example, 4-die Sapphire Rapids platform has the following + UPI 0 topology:: + + # tail /sys/devices/uncore_upi_0/die* + ==> /sys/devices/uncore_upi_0/die0 <== + upi_1,die_1 + ==> /sys/devices/uncore_upi_0/die1 <== + upi_0,die_3 + ==> /sys/devices/uncore_upi_0/die2 <== + upi_1,die_3 + ==> /sys/devices/uncore_upi_0/die3 <== + upi_0,die_1 + + Which means:: + + UPI link 0 on die 0 is connected to UPI link 1 on die 1 + UPI link 0 on die 1 is connected to UPI link 0 on die 3 + UPI link 0 on die 2 is connected to UPI link 1 on die 3 + UPI link 0 on die 3 is connected to UPI link 0 on die 1 \ No newline at end of file -- cgit v1.3.1