[lkml]   [2010]   [Sep]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: [PATCH] perf_events: improve DS/BTS/PEBS buffer allocation
    Stephane Eranian <> writes:

    > The DS, BTS, and PEBS memory regions were allocated using kzalloc(), i.e.,
    > requesting contiguous physical memory. There is no such restriction on
    > DS, PEBS and BTS buffers. Using kzalloc() could lead to error in case
    > no contiguous physical memory is available. BTS is requesting 64KB,
    > thus it can cause issues. PEBS is currently only requesting one page.
    > Both PEBS and BTS are static buffers allocated for each CPU at the
    > first user. When the last user exists, the buffers are released.

    DS supports page tables, but I have some doubts it really
    supports page faults. vmalloc today does page faults.

    I think the change is a good idea, but it will need vmalloc_sync_all()


    -- -- Speaking for myself only.

     \ /
      Last update: 2010-09-13 21:37    [W:0.019 / U:2.980 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site