lkml.org 
[lkml]   [2008]   [Mar]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH 06/10] x86: reduce memory and stack usage in intel_cacheinfo

    * H. Peter Anvin <hpa@zytor.com> wrote:

    > Ingo Molnar wrote:
    >>> The main goal was to avoid allocating 4096 bytes when only 32 would do
    >>> (characters needed to represent nr_cpu_ids cpus instead of NR_CPUS cpus.)
    >>> But I'll look at cleaning it up a bit more. It wouldn't have to be a
    >>> function if CHUNKSZ in cpumask_scnprintf() were visible (or a
    >>> non-changeable constant.)
    >>
    >> well, do we care about allocating 4096 bytes, as long as we also free it?
    >> It's not like we need to clear all the bytes or something. Am i missing
    >> something here?
    >
    > Well, 32 bytes fits on the stack, whereas 4096 bytes requires
    > allocating a page -- which means either taking the risk of failing or
    > blocking. Of course, we're doing this for output, which has the same
    > issue.

    hm, i thought this was all implemented via dynamic allocation already,
    within the cpumask_scnprintf function. But i see it doesnt do it - i
    guess a new call could be introduced, cpumask_scnprintf_ptr() which
    passes in a cpumask pointer and does dynamic allocation itself?

    Ingo


    \
     
     \ /
      Last update: 2008-03-26 18:39    [W:0.023 / U:238.720 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site