| commit | d504bed676caad29a3dba3d3727298c560628f5c | |
| author | Michael Neuling <mikey@neuling.org> | |
| Mon, 10 May 2010 20:28:26 +0000 (10 20:28 +0000) | ||
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | |
| Fri, 21 May 2010 07:31:11 +0000 (21 17:31 +1000) | ||
| tree | ea7077d57b3e3018dc6be5b8687889283ba3f6e6 | treesnapshot (tar.gz zip) |
| parent | f90ece28c1f5b3ec13fe481406857fe92f4bc7d1 | commitdiff |
powerpc/kexec: Speedup kexec hash PTE tear down
Currently for kexec the PTE tear down on 1TB segment systems normally
requires 3 hcalls for each PTE removal. On a machine with 32GB of
memory it can take around a minute to remove all the PTEs.
This optimises the path so that we only remove PTEs that are valid.
It also uses the read 4 PTEs at once HCALL. For the common case where
a PTEs is invalid in a 1TB segment, this turns the 3 HCALLs per PTE
down to 1 HCALL per 4 PTEs.
This gives an > 10x speedup in kexec times on PHYP, taking a 32GB
machine from around 1 minute down to a few seconds.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Currently for kexec the PTE tear down on 1TB segment systems normally
requires 3 hcalls for each PTE removal. On a machine with 32GB of
memory it can take around a minute to remove all the PTEs.
This optimises the path so that we only remove PTEs that are valid.
It also uses the read 4 PTEs at once HCALL. For the common case where
a PTEs is invalid in a 1TB segment, this turns the 3 HCALLs per PTE
down to 1 HCALL per 4 PTEs.
This gives an > 10x speedup in kexec times on PHYP, taking a 32GB
machine from around 1 minute down to a few seconds.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| arch/powerpc/platforms/pseries/lpar.c | diffblobblamehistory |