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| author | Al Viro <viro@zeniv.linux.org.uk> | 2012-10-06 00:55:57 +0200 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2012-10-15 01:36:37 +0200 |
| commit | ff0ab8af9c3f36e7b6f716c3b9e8811a4202eec6 (patch) | |
| tree | 78f5dba557a1f91b868fa0118516562b6cd28244 /Documentation/cpu-freq/pcc-cpufreq.txt | |
| parent | parisc: switch to generic sys_execve() (diff) | |
| download | linux-ff0ab8af9c3f36e7b6f716c3b9e8811a4202eec6.tar.xz linux-ff0ab8af9c3f36e7b6f716c3b9e8811a4202eec6.zip | |
parisc: optimizations in copy_thread() and friends
* in user thread case the registers had been copied as part of task_struct
already; no need to do it in copy_thread().
* no need to store kernel stack pointer into regs->r21; we know its offset
anyway.
* no need to clobber r3 in sys_fork_wrapper and friends - r28 will do just
as well and *it* will be overwritten anyway.
* no need to mess with storing the return address for child - it should just
use syscall_exit.
* no need to bother with separate stack frame for sys_clone() - just branch
there and be done with that.
* no need to bother with wrapper_exit - we need it only on the child_return,
so let's just do it there.
* use the same ksp for kernel threads and userland ones, while we are at it,
and let ret_from_kernel_execve() go through the normal syscall_exit. More
straightforward is better here...
[fixes from jejb folded]
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'Documentation/cpu-freq/pcc-cpufreq.txt')
0 files changed, 0 insertions, 0 deletions