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author | Sumitra Sharma <sumitraartsy@gmail.com> | 2023-06-10 20:57:12 +0300 |
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committer | Andrew Morton <akpm@linux-foundation.org> | 2023-08-18 20:18:50 +0300 |
commit | ae96e0cdc78c816b93f9617d65d144162692c09c (patch) | |
tree | f94355563a9cb7303fe1b6fb8ecc63dc41623b03 /arch/ia64 | |
parent | f58a2dd8d5d01b3ece13af7915745b8e7de20afe (diff) | |
download | linux-ae96e0cdc78c816b93f9617d65d144162692c09c.tar.xz |
lib: replace kmap() with kmap_local_page()
kmap() has been deprecated in favor of the kmap_local_page() due to high
cost, restricted mapping space, the overhead of a global lock for
synchronization, and making the process sleep in the absence of free
slots.
kmap_local_page() is faster than kmap() and offers thread-local and
CPU-local mappings, take pagefaults in a local kmap region and preserves
preemption by saving the mappings of outgoing tasks and restoring those of
the incoming one during a context switch.
The mappings are kept thread local in the functions “dmirror_do_read”
and “dmirror_do_write” in test_hmm.c
Therefore, replace kmap() with kmap_local_page() and use
mempcy_from/to_page() to avoid open coding kmap_local_page() + memcpy() +
kunmap_local().
Remove the unused variable “tmp”.
Link: https://lkml.kernel.org/r/20230610175712.GA348514@sumitra.com
Signed-off-by: Sumitra Sharma <sumitraartsy@gmail.com>
Suggested-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Reviewed-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Cc: Deepak R Varma <drv@mailo.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'arch/ia64')
0 files changed, 0 insertions, 0 deletions