lkml.org 
[lkml]   [2008]   [May]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH 01/10] Fix idr_remove()
    Andrew Morton wrote:
    > On Tue, 29 Apr 2008 16:33:05 +0200
    > Nadia.Derbey@bull.net wrote:
    >
    >
    >>[PATCH 01/10]
    >>
    >>This patch fixes idr_remove(): the return inside the loop makes us free only
    >>a single layer.
    >>
    >>Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net>
    >>
    >>---
    >> lib/idr.c | 2 +-
    >> 1 file changed, 1 insertion(+), 1 deletion(-)
    >>
    >>Index: linux-2.6.25-mm1/lib/idr.c
    >>===================================================================
    >>--- linux-2.6.25-mm1.orig/lib/idr.c 2008-04-25 15:29:00.000000000 +0200
    >>+++ linux-2.6.25-mm1/lib/idr.c 2008-04-25 15:48:34.000000000 +0200
    >>@@ -385,8 +385,8 @@ void idr_remove(struct idr *idp, int id)
    >> while (idp->id_free_cnt >= IDR_FREE_MAX) {
    >> p = alloc_layer(idp);
    >> kmem_cache_free(idr_layer_cache, p);
    >>- return;
    >> }
    >>+ return;
    >> }
    >> EXPORT_SYMBOL(idr_remove);
    >
    >
    > erk, ancient bug.
    >
    > I _think_ the implications of this are that an idr tree will grow fatter
    > than it needs to be, but there is no permanent leak: idr_destroy() will
    > still free everything, yes?

    Yes, exactly. Actually, I've not checked whether all the kernel
    components call idr_destroy() when needed.

    >
    > And a consequence of the fix is that idr manipulations will now result in
    > more allocs and frees,

    Not necessarily more allocs: this loop keeps IDR_FREE_MAX layers in the
    free list. So idr_pre_get() should be a noop.

    > but the amount of memory which a tree uses will be
    > less?
    >
    >
    >

    Regards,
    Nadia




    \
     
     \ /
      Last update: 2008-05-05 11:29    [W:0.023 / U:0.284 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site