• Stephane Eranian's avatar
    [PATCH] i386: i386 make NMI use PERFCTR1 for architectural perfmon (take 2) · bf8696ed
    Stephane Eranian authored
    Hello,
    
    This patch against 2.6.20-git14 makes the NMI watchdog use PERFSEL1/PERFCTR1
    instead of PERFSEL0/PERFCTR0 on processors supporting Intel architectural
    perfmon, such as Intel Core 2. Although all PMU events can work on
    both counters, the Precise Event-Based Sampling (PEBS) requires that the
    event be in PERFCTR0 to work correctly (see section 18.14.4.1 in the
    IA32 SDM Vol 3b).
    
    A similar patch for x86-64 is to follow.
    
    Changelog:
            - make the i386 NMI watchdog use PERFSEL1/PERFCTR1 instead of PERFSEL0/PERFCTR0
              on processors supporting the Intel architectural perfmon (e.g. Core 2 Duo).
              This allows PEBS to work when the NMI watchdog is active.
    signed-off-by: default avatarstephane eranian <eranian@hpl.hp.com>
    Signed-off-by: default avatarAndi Kleen <ak@suse.de>
    bf8696ed
nmi.c 28.9 KB