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    Subject[PATCH v5 0/3] of: cache phandle nodes to reduce cost of of_find_node_by_phandle()
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    From: Frank Rowand <frank.rowand@sony.com>

    Create a cache of the nodes that contain a phandle property. Use this
    cache to find the node for a given phandle value instead of scanning
    the devicetree to find the node. If the phandle value is not found
    in the cache, of_find_node_by_phandle() will fall back to the tree
    scan algorithm.

    Size and performance data is in patch 1/3 comments

    Changes since v4:
    - Add patch 2/3 "memblock: add memblock_free() alloc when
    CONFIG_HAVE_MEMBLOCK is not set"
    - patch 3/3 (previously 2/2): add checks for zero returned by
    memblock_virt_alloc()

    Changes since v3:
    - of_populate_phandle_cache(): add check for failed memory allocation
    - add patch 2/2 into series instead of as a standalone patch that was
    dependent on patch 1/2 of this series

    Changes since v2:
    - add mask to calculation of phandle cache entry
    - which results in better overhead reduction for devicetrees with
    phandle properties not allocated in the monotonically increasing
    range of 1..n
    - due to mask, number of entries in cache potentially increased to
    next power of two
    - minor fixes as suggested by reviewers
    - no longer using live_tree_max_phandle() so do not move it from
    drivers/of/resolver.c to drivers/of/base.c

    Changes since v1:
    - change short description from
    of: cache phandle nodes to reduce cost of of_find_node_by_phandle()
    - rebase on v4.16-rc1
    - reorder new functions in base.c to avoid forward declaration
    - add locking around kfree(phandle_cache) for memory ordering
    - add explicit check for non-null of phandle_cache in
    of_find_node_by_phandle(). There is already a check for !handle,
    which prevents accessing a null phandle_cache, but that dependency
    is not obvious, so this check makes it more apparent.
    - do not free phandle_cache if modules are enabled, so that
    cached phandles will be available when modules are loaded



    Frank Rowand (3):
    of: cache phandle nodes to reduce cost of of_find_node_by_phandle()
    memblock: add memblock_free() alloc when CONFIG_HAVE_MEMBLOCK is not
    set
    of: add early boot allocation of of_find_node_by_phandle() cache

    drivers/of/base.c | 124 +++++++++++++++++++++++++++++++++++++++++++++--
    drivers/of/fdt.c | 2 +
    drivers/of/of_private.h | 5 ++
    drivers/of/resolver.c | 3 --
    include/linux/memblock.h | 4 ++
    5 files changed, 131 insertions(+), 7 deletions(-)

    --
    Frank Rowand <frank.rowand@sony.com>

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