Comment 6 for bug 2020139

Reviewed: https://review.opendev.org/c/openstack/python-glanceclient/+/924060
Committed: https://opendev.org/openstack/python-glanceclient/commit/3a2ef8b105ef46cc46df90d5b6cee71b909855f1
Submitter: "Zuul (22348)"
Branch: stable/2023.1

commit 3a2ef8b105ef46cc46df90d5b6cee71b909855f1
Author: Nobuto Murata <email address hidden>
Date: Fri May 19 09:36:49 2023 +0900

    Bump the CHUNKSIZE to use CPU more efficiently

    The chunk size used for downloading images was 64KiB for some time. That
    is okay for relatively small images but the client side of CPU can be a
    bottleneck especially for large images. Bump the default chunk size from
    64KiB to 1MiB so we can use the client side CPU more efficiently.

    [64KiB chunk size - current]
    INFO cinder.image.image_utils Image download 1907.35 MB at 68.61 MB/s
    -> ~ 549 Mbps

    [1MiB chunk size - patched]
    INFO cinder.image.image_utils Image download 1907.35 MB at 132.10 MB/s
    -> 1,057 Mbps

    Closes-Bug: #2020139
    Change-Id: I8b6e19621fc989526b02319d88fcfde88a17eee0
    (cherry picked from commit 7d78cc4b9d43f5abdf8c7fa05e37ab8c8122c325)