Hi All, I am using 4.7 kernel. Sometimes I see prefetchable region memory is not getting allocated ...What could be possible reason and how to debug it. Pls suggest. In below snippet the red region doesn't appear sometimes after reboot. root@krishna# lspci -H1 -vs '00:03.1' 00:03.1 PCI bridge: Intel Corporation Xeon E7 v4/Xeon E5 v4/Xeon E3 v4/Xeon D PCI Express Root Port 3 (rev 03) (prog-if 00 [Normal decode]) Flags: bus master, fast devsel, latency 0, IRQ 11 Bus: primary=00, secondary=6d, subordinate=d4, sec-latency=0 Memory behind bridge: b0500000-b7afffff *Prefetchable memory behind bridge: 0000380200000000-* 000038033fffffff Capabilities: [40] Subsystem: Intel Corporation Device 0000 Capabilities: [60] MSI: Enable- Count=1/2 Maskable+ 64bit- Capabilities: [90] Express Root Port (Slot-), MSI 00 Capabilities: [e0] Power Management version 3 mgmt1-active# find /sys | grep drivers.*00:03 /sys/bus/pci/drivers/pcieport/0000:00:03.0 This problem is not consistent. It only occurs after few reboots. Does this prefetchable memory region depends on driver or it depends on Bios? Br/Krish