crypto: scompress - Use per-CPU struct instead multiple variables
Two per-CPU variables are allocated as pointer to per-CPU memory which
then are used as scratch buffers.
We could be smart about this and use instead a per-CPU struct which
contains the pointers already and then we need to allocate just the
scratch buffers.
Add a lock to the struct. By doing so we can avoid the get_cpu()
statement and gain lockdep coverage (if enabled) to ensure that the lock
is always acquired in the right context. On non-preemptible kernels the
lock vanishes.
It is okay to use raw_cpu_ptr() in order to get a pointer to the struct
since it is protected by the spinlock.
The diffstat of this is negative and according to size scompress.o:
text data bss dec hex filename
1847 160 24 2031 7ef dbg_before.o
1754 232 4 1990 7c6 dbg_after.o
1799 64 24 1887 75f no_dbg-before.o
1703 88 4 1795 703 no_dbg-after.o
The overall size increase difference is also negative. The increase in
the data section is only four bytes without lockdep.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
1 file changed
