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xen/libxc-sr-save-errors.patch

110 lines
4.2 KiB
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From: Olaf Hering <olaf@aepfle.de>
Date: Fri, 23 Oct 2020 11:26:05 +0200
Subject: libxc sr save errors
tools: save: preallocate errors array
Remove repeated allocation from migration loop. There will never be
more than MAX_BATCH_SIZE pages to process in a batch.
Allocate the space once.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
---
tools/libs/guest/xg_sr_common.h | 1 +
tools/libs/guest/xg_sr_save.c | 20 ++++++++++----------
2 files changed, 11 insertions(+), 10 deletions(-)
--- a/tools/libs/guest/xg_sr_common.h
+++ b/tools/libs/guest/xg_sr_common.h
@@ -246,6 +246,7 @@ struct xc_sr_context
xen_pfn_t *batch_pfns;
xen_pfn_t *mfns;
xen_pfn_t *types;
+ int *errors;
unsigned int nr_batch_pfns;
unsigned long *deferred_pages;
unsigned long nr_deferred_pages;
--- a/tools/libs/guest/xg_sr_save.c
+++ b/tools/libs/guest/xg_sr_save.c
@@ -91,7 +91,7 @@ static int write_batch(struct xc_sr_cont
void *guest_mapping = NULL;
void **guest_data = NULL;
void **local_pages = NULL;
- int *errors = NULL, rc = -1;
+ int rc = -1;
unsigned int i, p, nr_pages = 0, nr_pages_mapped = 0;
unsigned int nr_pfns = ctx->save.nr_batch_pfns;
void *page, *orig_page;
@@ -104,8 +104,6 @@ static int write_batch(struct xc_sr_cont
assert(nr_pfns != 0);
- /* Errors from attempting to map the gfns. */
- errors = malloc(nr_pfns * sizeof(*errors));
/* Pointers to page data to send. Mapped gfns or local allocations. */
guest_data = calloc(nr_pfns, sizeof(*guest_data));
/* Pointers to locally allocated pages. Need freeing. */
@@ -113,7 +111,7 @@ static int write_batch(struct xc_sr_cont
/* iovec[] for writev(). */
iov = malloc((nr_pfns + 4) * sizeof(*iov));
- if ( !errors || !guest_data || !local_pages || !iov )
+ if ( !guest_data || !local_pages || !iov )
{
ERROR("Unable to allocate arrays for a batch of %u pages",
nr_pfns);
@@ -158,8 +156,8 @@ static int write_batch(struct xc_sr_cont
if ( nr_pages > 0 )
{
- guest_mapping = xenforeignmemory_map(
- xch->fmem, ctx->domid, PROT_READ, nr_pages, ctx->save.mfns, errors);
+ guest_mapping = xenforeignmemory_map(xch->fmem, ctx->domid, PROT_READ,
+ nr_pages, ctx->save.mfns, ctx->save.errors);
if ( !guest_mapping )
{
PERROR("Failed to map guest pages");
@@ -172,10 +170,11 @@ static int write_batch(struct xc_sr_cont
if ( !page_type_has_stream_data(ctx->save.types[i]) )
continue;
- if ( errors[p] )
+ if ( ctx->save.errors[p] )
{
ERROR("Mapping of pfn %#"PRIpfn" (mfn %#"PRIpfn") failed %d",
- ctx->save.batch_pfns[i], ctx->save.mfns[p], errors[p]);
+ ctx->save.batch_pfns[i], ctx->save.mfns[p],
+ ctx->save.errors[p]);
goto err;
}
@@ -271,7 +270,6 @@ static int write_batch(struct xc_sr_cont
free(iov);
free(local_pages);
free(guest_data);
- free(errors);
return rc;
}
@@ -846,10 +844,11 @@ static int setup(struct xc_sr_context *c
sizeof(*ctx->save.batch_pfns));
ctx->save.mfns = malloc(MAX_BATCH_SIZE * sizeof(*ctx->save.mfns));
ctx->save.types = malloc(MAX_BATCH_SIZE * sizeof(*ctx->save.types));
+ ctx->save.errors = malloc(MAX_BATCH_SIZE * sizeof(*ctx->save.errors));
ctx->save.deferred_pages = bitmap_alloc(ctx->save.p2m_size);
if ( !ctx->save.batch_pfns || !ctx->save.mfns || !ctx->save.types ||
- !dirty_bitmap || !ctx->save.deferred_pages )
+ !ctx->save.errors || !dirty_bitmap || !ctx->save.deferred_pages )
{
ERROR("Unable to allocate memory for dirty bitmaps, batch pfns and"
" deferred pages");
@@ -880,6 +879,7 @@ static void cleanup(struct xc_sr_context
xc_hypercall_buffer_free_pages(xch, dirty_bitmap,
NRPAGES(bitmap_size(ctx->save.p2m_size)));
free(ctx->save.deferred_pages);
+ free(ctx->save.errors);
free(ctx->save.types);
free(ctx->save.mfns);
free(ctx->save.batch_pfns);