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    SubjectRe: [PATCH] enforce function inlining for hot functions
    On Thu, 23 Apr 2015 23:40:01 +0200 Hagen Paul Pfeifer <hagen@jauu.net> wrote:

    > GCC inlining heuristics are sometimes quizzical. Especially with inline
    > assembler constructs GCC seems to have issues. A allyesconfig show a rather
    > long list of functions where GCC inlining decisions are questionable (not
    > inlined).

    I can't reproduce this with either gcc-4.8.2 or gcc-4.4.4. The patch
    makes zero difference to `size vmlinux' and a bit of poking around with
    nm doesn't show any out-of-lined versions of the functions you
    identify.

    So. More details, please. How to demonstrate this, gcc versions, etc.

    > Furthermore, because the functions are declared with static
    > linkage each function is copied n times - and n can be rather high:
    >
    > atomic_inc: 544 duplicates
    > rcu_read_unlock: 453 duplicates
    > rcu_read_lock: 383 duplicates
    > get_dma_ops: 271 duplicates
    > arch_local_irq_restore: 258 duplicates
    > atomic_dec: 215 duplicates
    > kzalloc: 185 duplicates
    > cpumask_check: 157 duplicates
    > test_and_set_bit: 156 duplicates
    > cpumask_next: 146 duplicates
    > list_del: 131 duplicates
    > kref_get: 126 duplicates

    That's pretty pathetic.


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