Linux Driver for APIC Authors: Berkley Shands, John DeHart, - PDF document

Linux Driver for APIC • Authors: Berkley Shands, John DeHart, Rezwani Kabir • Linux Kernel versions 2.2.X (user mode only) • 2.3.99-pre6 (stable) • 2.4.0-test1 (intel/alpha with patches) • 2.4.0-test2 (intel only) Linux Driver Features • Supports multiple apics in one box • Supports 32 or 64 bit machines (intel X86 and Alpha (XP1000)) • AAL5 frames up to 65K long • AAL0 single cell (not tested) • Linux ATM 0.77 compatible • 4Kb input buffers 1

Linux Driver • 1MB pool for Descriptors • 1MB pool for shadow set • 1MB pool for input frames (permanently allocated) Known Bugs • High input cell rates (blasting) hang up the interrupt driver (fix available) • Alpha PCI bus and Bridges – APIC_STUCK_BIT • Not module loadable (I have not tried ☺ ) • Syscall(APIC, RESET) hangs IP driver. 2

Remaining Work • Remove debug statements • Tune for smaller vs larger machines • Test AAL0 interface • Package for Distribution Driver Details • Ap_vcc + atm_vcc + ap_dev • Pool buffers AAL5 fixed size, never reclaimed (reused only out of shadow set) • Larger MTU in ifconfig (up to 65K) Performance! • Slab.c updated for big entries 3

Slides by Suzy ☺ • This Power Point display was rendered by Suzy(9). 4