# HG changeset patch
# User kfraser@xxxxxxxxxxxxxxxxxxxxx
# Node ID 33aca302b6109179194276885d7b29e0ad5033ab
# Parent 10fb002727ef3df7c06d920af565efd8f3acfdc7
[LINUX] Improve single-page contiguous region creation/destruction
Batch page table updates and fold TLB flush into last one, reducing
number of hypercalls made from ((# of pages) + 1) to just 1.
Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>
---
linux-2.6-xen-sparse/arch/i386/mm/hypervisor.c | 41 ++++++++++++++-----------
1 files changed, 23 insertions(+), 18 deletions(-)
diff -r 10fb002727ef -r 33aca302b610
linux-2.6-xen-sparse/arch/i386/mm/hypervisor.c
--- a/linux-2.6-xen-sparse/arch/i386/mm/hypervisor.c Tue Jul 25 15:50:04
2006 +0100
+++ b/linux-2.6-xen-sparse/arch/i386/mm/hypervisor.c Tue Jul 25 15:58:35
2006 +0100
@@ -266,6 +266,7 @@ static void contiguous_bitmap_clear(
/* Protected by balloon_lock. */
#define MAX_CONTIG_ORDER 9 /* 2MB */
static unsigned long discontig_frames[1<<MAX_CONTIG_ORDER];
+static multicall_entry_t cr_mcl[1<<MAX_CONTIG_ORDER];
/* Ensure multi-page extents are contiguous in machine memory. */
int xen_create_contiguous_region(
@@ -310,12 +311,13 @@ int xen_create_contiguous_region(
/* 1. Zap current PTEs, remembering MFNs. */
for (i = 0; i < (1UL<<order); i++) {
in_frames[i] = pfn_to_mfn((__pa(vstart) >> PAGE_SHIFT) + i);
- if (HYPERVISOR_update_va_mapping(vstart + (i*PAGE_SIZE),
- __pte_ma(0), 0))
- BUG();
+ MULTI_update_va_mapping(cr_mcl + i, vstart + (i*PAGE_SIZE),
+ __pte_ma(0), 0);
set_phys_to_machine((__pa(vstart)>>PAGE_SHIFT)+i,
INVALID_P2M_ENTRY);
}
+ if (HYPERVISOR_multicall(cr_mcl, i))
+ BUG();
/* 2. Get a new contiguous memory extent. */
out_frame = __pa(vstart) >> PAGE_SHIFT;
@@ -343,15 +345,16 @@ int xen_create_contiguous_region(
/* 3. Map the new extent in place of old pages. */
for (i = 0; i < (1UL<<order); i++) {
frame = success ? (out_frame + i) : in_frames[i];
- if (HYPERVISOR_update_va_mapping(vstart + (i*PAGE_SIZE),
- pfn_pte_ma(frame,
- PAGE_KERNEL),
- 0))
- BUG();
+ MULTI_update_va_mapping(cr_mcl + i, vstart + (i*PAGE_SIZE),
+ pfn_pte_ma(frame, PAGE_KERNEL), 0);
set_phys_to_machine((__pa(vstart)>>PAGE_SHIFT)+i, frame);
}
- flush_tlb_all();
+ cr_mcl[i - 1].args[MULTI_UVMFLAGS_INDEX] = order
+ ? UVMF_TLB_FLUSH|UVMF_ALL
+ : UVMF_INVLPG|UVMF_ALL;
+ if (HYPERVISOR_multicall(cr_mcl, i))
+ BUG();
if (success)
contiguous_bitmap_set(__pa(vstart) >> PAGE_SHIFT,
@@ -402,13 +405,14 @@ void xen_destroy_contiguous_region(unsig
/* 2. Zap current PTEs. */
for (i = 0; i < (1UL<<order); i++) {
- if (HYPERVISOR_update_va_mapping(vstart + (i*PAGE_SIZE),
- __pte_ma(0), 0))
- BUG();
+ MULTI_update_va_mapping(cr_mcl + i, vstart + (i*PAGE_SIZE),
+ __pte_ma(0), 0);
set_phys_to_machine((__pa(vstart)>>PAGE_SHIFT)+i,
INVALID_P2M_ENTRY);
out_frames[i] = (__pa(vstart) >> PAGE_SHIFT) + i;
}
+ if (HYPERVISOR_multicall(cr_mcl, i))
+ BUG();
/* 3. Do the exchange for non-contiguous MFNs. */
rc = HYPERVISOR_memory_op(XENMEM_exchange, &exchange);
@@ -429,15 +433,16 @@ void xen_destroy_contiguous_region(unsig
/* 4. Map new pages in place of old pages. */
for (i = 0; i < (1UL<<order); i++) {
frame = success ? out_frames[i] : (in_frame + i);
- if (HYPERVISOR_update_va_mapping(vstart + (i*PAGE_SIZE),
- pfn_pte_ma(frame,
- PAGE_KERNEL),
- 0))
- BUG();
+ MULTI_update_va_mapping(cr_mcl + i, vstart + (i*PAGE_SIZE),
+ pfn_pte_ma(frame, PAGE_KERNEL), 0);
set_phys_to_machine((__pa(vstart)>>PAGE_SHIFT)+i, frame);
}
- flush_tlb_all();
+ cr_mcl[i - 1].args[MULTI_UVMFLAGS_INDEX] = order
+ ? UVMF_TLB_FLUSH|UVMF_ALL
+ : UVMF_INVLPG|UVMF_ALL;
+ if (HYPERVISOR_multicall(cr_mcl, i))
+ BUG();
balloon_unlock(flags);
}
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