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author | Adhemerval Zanella <azanella@linux.vnet.ibm.com> | 2013-04-22 09:29:33 +0000 |
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committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2013-04-23 16:05:05 +1000 |
commit | fcb41a2030abe0eb716ef0798035ef9562097f42 (patch) | |
tree | 4b063cc1cb872fb9609fd90485c7b602b9fdc57f /lib/xz | |
parent | af81d7878c641629f2693ae3fdaf74b4af14dfca (diff) | |
download | blackbird-op-linux-fcb41a2030abe0eb716ef0798035ef9562097f42.tar.gz blackbird-op-linux-fcb41a2030abe0eb716ef0798035ef9562097f42.zip |
powerpc: Add VDSO version of time
On 04/18/2013 07:38 PM, Anton Blanchard wrote:
> Since you are only reading one long you shouldn't need to check the
> update count and loop, you will always see a consistent value. The
> system call version of time() just does an unprotected load for example.
Fixed.
> With the above change and with Michael's comments covered (decent
> changelog entry and Signed-off-by):
>
> Acked-by: Anton Blanchard <anton@samba.org>
Thanks for the review, below the updated patch:
From: Adhemerval Zanella <azanella@linux.vnet.ibm.com>
This patch implement the time syscall as vDSO. The performance speedups
are:
Baseline PPC32: 380 nsec
Baseline PPC64: 350 nsec
vdso PPC32: 20 nsec
vsdo PPC64: 20 nsec
Tested on 64 bit build with both 32 bit and 64 bit userland.
Acked-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Adhemerval Zanella <azanella@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'lib/xz')
0 files changed, 0 insertions, 0 deletions