lkml.org 
[lkml]   [2009]   [Sep]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH] percpu: fix unit_map[] verification in pcpu_setup_first_chunk()
    Christoph Lameter wrote:
    > On Tue, 29 Sep 2009, Tejun Heo wrote:
    >
    >> pcpu_setup_first_chunk() incorrectly used NR_CPUS as the impossible
    >> unit number while unit number can equal and go over NR_CPUS with
    >> sparse unit map. This triggers BUG_ON() spuriously on machines which
    >> have non-power-of-two number of cpus. Use UINT_MAX instead.
    >
    > Uhhh. Funky. The assumption nr_cpu_ids < NR_CPUS has been broken. Wonder
    > what other effects that will have. In particular since the slab and page
    > allocators have arrays indexed by the cpu number and those arrays are
    > dimensioned for NR_CPUS.

    Heh.. that's not what's broken. unit# can legally go over NR_CPUS or
    nr_cpu_ids as cpus can be sparsely mapped to units. The problem is
    that I didn't fix unit_map allocation. Will update the patch. Just a
    sec.

    --
    tejun


    \
     
     \ /
      Last update: 2009-09-28 18:39    [W:0.040 / U:0.848 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site