From: Olaf Hering <olaf@aepfle.de>
To: xen-devel@lists.xenproject.org
Cc: Olaf Hering <olaf@aepfle.de>, Ian Jackson <iwj@xenproject.org>,
Wei Liu <wl@xen.org>, Juergen Gross <jgross@suse.com>
Subject: [PATCH v20210713 10/31] tools: save: preallocate iov array
Date: Tue, 13 Jul 2021 20:05:44 +0200 [thread overview]
Message-ID: <20210713180605.12096-11-olaf@aepfle.de> (raw)
In-Reply-To: <20210713180605.12096-1-olaf@aepfle.de>
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 | 34 ++++++++++++++++-----------------
2 files changed, 18 insertions(+), 17 deletions(-)
diff --git a/tools/libs/guest/xg_sr_common.h b/tools/libs/guest/xg_sr_common.h
index d2b838ed33..e2a068bb7e 100644
--- a/tools/libs/guest/xg_sr_common.h
+++ b/tools/libs/guest/xg_sr_common.h
@@ -247,6 +247,7 @@ struct xc_sr_context
xen_pfn_t *mfns;
xen_pfn_t *types;
int *errors;
+ struct iovec *iov;
unsigned int nr_batch_pfns;
unsigned long *deferred_pages;
unsigned long nr_deferred_pages;
diff --git a/tools/libs/guest/xg_sr_save.c b/tools/libs/guest/xg_sr_save.c
index 5b416fda60..92eba456e6 100644
--- a/tools/libs/guest/xg_sr_save.c
+++ b/tools/libs/guest/xg_sr_save.c
@@ -96,7 +96,7 @@ static int write_batch(struct xc_sr_context *ctx)
unsigned int nr_pfns = ctx->save.nr_batch_pfns;
void *page, *orig_page;
uint64_t *rec_pfns = NULL;
- struct iovec *iov = NULL; int iovcnt = 0;
+ int iovcnt = 0;
struct xc_sr_rec_page_data_header hdr = { 0 };
struct xc_sr_record rec = {
.type = REC_TYPE_PAGE_DATA,
@@ -108,10 +108,8 @@ static int write_batch(struct xc_sr_context *ctx)
guest_data = calloc(nr_pfns, sizeof(*guest_data));
/* Pointers to locally allocated pages. Need freeing. */
local_pages = calloc(nr_pfns, sizeof(*local_pages));
- /* iovec[] for writev(). */
- iov = malloc((nr_pfns + 4) * sizeof(*iov));
- if ( !guest_data || !local_pages || !iov )
+ if ( !guest_data || !local_pages )
{
ERROR("Unable to allocate arrays for a batch of %u pages",
nr_pfns);
@@ -221,17 +219,17 @@ static int write_batch(struct xc_sr_context *ctx)
for ( i = 0; i < nr_pfns; ++i )
rec_pfns[i] = ((uint64_t)(ctx->save.types[i]) << 32) | ctx->save.batch_pfns[i];
- iov[0].iov_base = &rec.type;
- iov[0].iov_len = sizeof(rec.type);
+ ctx->save.iov[0].iov_base = &rec.type;
+ ctx->save.iov[0].iov_len = sizeof(rec.type);
- iov[1].iov_base = &rec.length;
- iov[1].iov_len = sizeof(rec.length);
+ ctx->save.iov[1].iov_base = &rec.length;
+ ctx->save.iov[1].iov_len = sizeof(rec.length);
- iov[2].iov_base = &hdr;
- iov[2].iov_len = sizeof(hdr);
+ ctx->save.iov[2].iov_base = &hdr;
+ ctx->save.iov[2].iov_len = sizeof(hdr);
- iov[3].iov_base = rec_pfns;
- iov[3].iov_len = nr_pfns * sizeof(*rec_pfns);
+ ctx->save.iov[3].iov_base = rec_pfns;
+ ctx->save.iov[3].iov_len = nr_pfns * sizeof(*rec_pfns);
iovcnt = 4;
ctx->save.pages_sent += nr_pages;
@@ -243,15 +241,15 @@ static int write_batch(struct xc_sr_context *ctx)
{
if ( guest_data[i] )
{
- iov[iovcnt].iov_base = guest_data[i];
- iov[iovcnt].iov_len = PAGE_SIZE;
+ ctx->save.iov[iovcnt].iov_base = guest_data[i];
+ ctx->save.iov[iovcnt].iov_len = PAGE_SIZE;
iovcnt++;
--nr_pages;
}
}
}
- if ( writev_exact(ctx->fd, iov, iovcnt) )
+ if ( writev_exact(ctx->fd, ctx->save.iov, iovcnt) )
{
PERROR("Failed to write page data to stream");
goto err;
@@ -267,7 +265,6 @@ static int write_batch(struct xc_sr_context *ctx)
xenforeignmemory_unmap(xch->fmem, guest_mapping, nr_pages_mapped);
for ( i = 0; local_pages && i < nr_pfns; ++i )
free(local_pages[i]);
- free(iov);
free(local_pages);
free(guest_data);
@@ -846,10 +843,12 @@ static int setup(struct xc_sr_context *ctx)
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.iov = malloc((4 + MAX_BATCH_SIZE) * sizeof(*ctx->save.iov));
ctx->save.deferred_pages = bitmap_alloc(ctx->save.p2m_size);
if ( !ctx->save.batch_pfns || !ctx->save.mfns || !ctx->save.types ||
- !ctx->save.errors || !dirty_bitmap || !ctx->save.deferred_pages )
+ !ctx->save.errors || !ctx->save.iov || !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 *ctx)
xc_hypercall_buffer_free_pages(xch, dirty_bitmap,
NRPAGES(bitmap_size(ctx->save.p2m_size)));
free(ctx->save.deferred_pages);
+ free(ctx->save.iov);
free(ctx->save.errors);
free(ctx->save.types);
free(ctx->save.mfns);
next prev parent reply other threads:[~2021-07-13 18:06 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-13 18:05 [PATCH v20210713 00/31] leftover from 2020 Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 01/31] tools: fix make rpmball Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 02/31] hotplug/Linux: fix starting of xenstored with restarting systemd Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 03/31] tools: add API to work with sevaral bits at once Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 04/31] xl: fix description of migrate --debug Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 05/31] tools: add readv_exact to libxenctrl Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 06/31] tools: show migration transfer rate in send_dirty_pages Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 07/31] tools: save: preallocate mfns array Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 08/31] tools: save: preallocate types array Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 09/31] tools: save: preallocate errors array Olaf Hering
2021-07-13 18:05 ` Olaf Hering [this message]
2021-07-13 18:05 ` [PATCH v20210713 11/31] tools: save: preallocate rec_pfns array Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 12/31] tools: save: preallocate guest_data array Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 13/31] tools: save: preallocate local_pages array Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 14/31] tools: restore: preallocate pfns array Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 15/31] tools: restore: preallocate types array Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 16/31] tools: restore: preallocate mfns array Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 17/31] tools: restore: preallocate map_errs array Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 18/31] tools: restore: preallocate populate_pfns pfns array Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 19/31] tools: restore: preallocate populate_pfns mfns array Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 20/31] tools: restore: split record processing Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 21/31] tools: restore: split handle_page_data Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 22/31] tools: restore: write data directly into guest Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 23/31] tools: recognize LIBXL_API_VERSION for 4.16 Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 24/31] tools: adjust libxl_domain_suspend to receive a struct props Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 25/31] tools: add callback to libxl for precopy_policy and precopy_stats Olaf Hering
2021-07-13 18:06 ` [PATCH v20210713 26/31] tools: add --max_iters to libxl_domain_suspend Olaf Hering
2021-07-13 18:06 ` [PATCH v20210713 27/31] tools: add --min_remaining " Olaf Hering
2021-07-13 18:06 ` [PATCH v20210713 28/31] tools: add --abort_if_busy " Olaf Hering
2021-07-13 18:06 ` [PATCH v20210713 29/31] tools: add API for expandable bitmaps Olaf Hering
2021-07-13 18:06 ` [PATCH v20210713 30/31] tools: use xg_sr_bitmap for populated_pfns Olaf Hering
2021-07-13 18:06 ` [PATCH v20210713 31/31] tools: use superpages during restore of HVM guest Olaf Hering
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