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    SubjectRe: [PATCH v2 2/2] btrfs-progs: Fix up memory leakage
    On 09/25/2012 12:14 PM, David Sterba wrote:
    > On Tue, Sep 25, 2012 at 10:02:16AM +0800, zwu.kernel@gmail.com wrote:
    >> From: Zhi Yong Wu<wuzhy@linux.vnet.ibm.com>
    >>
    >> Some code pathes forget to free memory on exit.
    >
    > Same as with the fd's, kernel will free all memory for us at exit().

    I strongly disagree with this approach. The callee often don't know what
    happen after and before the call. The same is true for the programmer,
    because the code is quite often updated by several people. A clean
    exit() is the right thing to do as general rule. I don't see any valid
    reason (in the btrfs context) to do otherwise.

    Relying on the exit() for a proper clean-up increase the likelihood of
    bug when the code evolves (see my patch [RESPOST][BTRFS-PROGS][PATCH]
    btrfs_read_dev_super(): uninitialized variable for an example of what
    means an incorrect deallocation of resource).

    > If there's lots of memory allocated, it may be even faster to leave the
    > unallocation process to kernel as it will do it in one go, while the
    > application would unnecessarily free it chunk by chunk.

    May be I am wrong, but I don't think that the increase of speed of the
    btrfs "command" is even measurable relying on exit instead of free()-ing
    each chunk of memory one at time.... The same should be true for the
    open()/close()

    My 2¢

    BR
    G.Baroncelli

    >
    > david
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