Hi, I just tryed linux-2.6.21-rc3 on my machine (P4HT 2.8GHz, with 512Mo) with Tickless System (Dynamic Ticks) and High Resolution Timer Support (.config in attachement) The problem is that the kernel hang on boot. I tried different configuration with nohz and highres on the kernel command line. The only combination that works is : nohz=off highres=off I also tried compiling the kernel without Tickless and without High resolution timer, this kernel is working ok and is one of the first kernel to suspend and resume from RAM. Congratulations ! ;p I tried to compile te kernel with only Tickless System or High Resolution timer, both hang on boot. The hang is just after : ACPI: PCI Interrupt 0000:00:1f.1[A] -> GSI 18 (level, low) -> IRQ 18 ICH5: chipset revision 2 ICH5: not 100% native mode: will probe irqs later ide0: BM-DMA at 0x2040-0x2047, BIOS settings: hda:DMA, hdb:pio ide1: BM-DMA at 0x2048-0x204f, BIOS settings: hdc:DMA, hdd:pio And I have the message : Switched to NOHZ mode on CPU #1 or Switched to high resolution mode on CPU #1 Depending on the option enabled/disabled What can I do to help find the bug ? dmesg and .config of the system booted with nohz=off highres=off are in attachements. Regards -- Stéphane Casset LOGIDÉE sàrl Se faire plaisir d'apprendre 1a, rue Pasteur Tel : +33 388 23 69 77 casset@logidee.com F-67540 OSTWALD Fax : +33 388 23 69 77 http://logidee.com