• Dennis Zhou (Facebook)'s avatar
    percpu: modify base_addr to be region specific · c0ebfdc3
    Dennis Zhou (Facebook) authored
    Originally, the first chunk was served by one or two chunks, each
    given a region they are responsible for. Despite this, the arithmetic
    was based off of the true base_addr of the chunk making it be overly
    inclusive.
    
    This patch moves the base_addr of chunks that are responsible for the
    first chunk. The base_addr must remain page aligned to keep the
    address alignment correct, so it is the beginning of the region served
    page aligned down. start_offset holds where the region served begins
    from this new base_addr.
    
    The corresponding percpu address checks are modified to be more specific
    as a result. The first chunk considers only the dynamic region and both
    first chunk and reserved chunk checks ignore the static region. The
    static region addresses should never be passed into the allocator. There
    is no impact here besides distinguishing the first chunk and making the
    checks specific.
    
    The percpu pointer to physical address is left intact as addresses are
    not given out in the non-allocated portion of percpu memory.
    
    nr_pages is added to pcpu_chunk to keep track of the size of the entire
    region served containing both start_offset and end_offset. This variable
    will be used to manage the bitmap allocator.
    Signed-off-by: default avatarDennis Zhou <dennisszhou@gmail.com>
    Reviewed-by: default avatarJosef Bacik <jbacik@fb.com>
    Signed-off-by: default avatarTejun Heo <tj@kernel.org>
    c0ebfdc3
percpu-internal.h 4.15 KB