diff options
| author | Michael Neuling <mikey@neuling.org> | 2010-05-10 20:28:26 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-03-14 14:29:57 -0700 |
| commit | 553c9ca59794cff92d010fadc1aed89f47b47a20 (patch) | |
| tree | 556af951564c48dcd36f21daecfcf87083df2646 /arch | |
| parent | 2059788cc18e6e2ed634de4fed649a3ea31323ed (diff) | |
powerpc/kexec: Speedup kexec hash PTE tear down
commit d504bed676caad29a3dba3d3727298c560628f5c upstream.
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>
Signed-off-by: Kamalesh babulal <kamalesh@linux.vnet.ibm.com>
cc: Anton Blanchard <anton@samba.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/platforms/pseries/lpar.c | 33 |
1 files changed, 20 insertions, 13 deletions
diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c index 903eb9eec687..5f2c511def65 100644 --- a/arch/powerpc/platforms/pseries/lpar.c +++ b/arch/powerpc/platforms/pseries/lpar.c @@ -366,21 +366,28 @@ static void pSeries_lpar_hptab_clear(void) { unsigned long size_bytes = 1UL << ppc64_pft_size; unsigned long hpte_count = size_bytes >> 4; - unsigned long dummy1, dummy2, dword0; + struct { + unsigned long pteh; + unsigned long ptel; + } ptes[4]; long lpar_rc; - int i; + int i, j; - /* TODO: Use bulk call */ - for (i = 0; i < hpte_count; i++) { - /* dont remove HPTEs with VRMA mappings */ - lpar_rc = plpar_pte_remove_raw(H_ANDCOND, i, HPTE_V_1TB_SEG, - &dummy1, &dummy2); - if (lpar_rc == H_NOT_FOUND) { - lpar_rc = plpar_pte_read_raw(0, i, &dword0, &dummy1); - if (!lpar_rc && ((dword0 & HPTE_V_VRMA_MASK) - != HPTE_V_VRMA_MASK)) - /* Can be hpte for 1TB Seg. So remove it */ - plpar_pte_remove_raw(0, i, 0, &dummy1, &dummy2); + /* Read in batches of 4, + * invalidate only valid entries not in the VRMA + * hpte_count will be a multiple of 4 + */ + for (i = 0; i < hpte_count; i += 4) { + lpar_rc = plpar_pte_read_4_raw(0, i, (void *)ptes); + if (lpar_rc != H_SUCCESS) + continue; + for (j = 0; j < 4; j++){ + if ((ptes[j].pteh & HPTE_V_VRMA_MASK) == + HPTE_V_VRMA_MASK) + continue; + if (ptes[j].pteh & HPTE_V_VALID) + plpar_pte_remove_raw(0, i + j, 0, + &(ptes[j].pteh), &(ptes[j].ptel)); } } } |