ebd0a23ab5
- kvm-migration-multifd-move-macros-to-multifd-header.patch [RHEL-59697] - kvm-migration-refactor-channel-discovery-mechanism.patch [RHEL-59697] - kvm-migration-Add-save_postcopy_prepare-savevm-handler.patch [RHEL-59697] - kvm-migration-ram-Implement-save_postcopy_prepare.patch [RHEL-59697] - kvm-tests-qtest-migration-consolidate-set-capabilities.patch [RHEL-59697] - kvm-migration-write-zero-pages-when-postcopy-enabled.patch [RHEL-59697] - kvm-migration-enable-multifd-and-postcopy-together.patch [RHEL-59697] - kvm-migration-Add-qtest-for-migration-over-RDMA.patch [RHEL-59697] - kvm-qtest-migration-rdma-Enforce-RLIMIT_MEMLOCK-128MB-re.patch [RHEL-59697] - kvm-qtest-migration-rdma-Add-test-for-rdma-migration-wit.patch [RHEL-59697] - kvm-tests-qtest-migration-add-postcopy-tests-with-multif.patch [RHEL-59697] - kvm-file-posix-Fix-aio-threads-performance-regression-af.patch [RHEL-96854] - kvm-block-remove-outdated-comments-about-AioContext-lock.patch [RHEL-88561] - kvm-block-move-drain-outside-of-read-locked-bdrv_reopen_.patch [RHEL-88561] - kvm-block-snapshot-move-drain-outside-of-read-locked-bdr.patch [RHEL-88561] - kvm-block-move-drain-outside-of-read-locked-bdrv_inactiv.patch [RHEL-88561] - kvm-block-mark-bdrv_parent_change_aio_context-GRAPH_RDLO.patch [RHEL-88561] - kvm-block-mark-change_aio_ctx-callback-and-instances-as-.patch [RHEL-88561] - kvm-block-mark-bdrv_child_change_aio_context-GRAPH_RDLOC.patch [RHEL-88561] - kvm-block-move-drain-outside-of-bdrv_change_aio_context-.patch [RHEL-88561] - kvm-block-move-drain-outside-of-bdrv_try_change_aio_cont.patch [RHEL-88561] - kvm-block-move-drain-outside-of-bdrv_attach_child_common.patch [RHEL-88561] - kvm-block-move-drain-outside-of-bdrv_set_backing_hd_drai.patch [RHEL-88561] - kvm-block-move-drain-outside-of-bdrv_root_attach_child.patch [RHEL-88561] - kvm-block-move-drain-outside-of-bdrv_attach_child.patch [RHEL-88561] - kvm-block-move-drain-outside-of-quorum_add_child.patch [RHEL-88561] - kvm-block-move-drain-outside-of-bdrv_root_unref_child.patch [RHEL-88561] - kvm-block-move-drain-outside-of-quorum_del_child.patch [RHEL-88561] - kvm-blockdev-drain-while-unlocked-in-internal_snapshot_a.patch [RHEL-88561] - kvm-blockdev-drain-while-unlocked-in-external_snapshot_a.patch [RHEL-88561] - kvm-block-mark-bdrv_drained_begin-and-friends-as-GRAPH_U.patch [RHEL-88561] - kvm-iotests-graph-changes-while-io-remove-image-file-aft.patch [RHEL-88561] - kvm-iotests-graph-changes-while-io-add-test-case-with-re.patch [RHEL-88561] - Resolves: RHEL-59697 (Allow multifd+postcopy features being enabled together, but only use multifd during precopy ) - Resolves: RHEL-96854 (Performance Degradation(aio=threads) between Upstream Commit b75c5f9 and 984a32f) - Resolves: RHEL-88561 (qemu graph deadlock during job-dismiss)
70 lines
2.8 KiB
Diff
70 lines
2.8 KiB
Diff
From d25e369e01fcb30d4d12802907372d3320c095ff Mon Sep 17 00:00:00 2001
|
|
From: Prasad Pandit <pjp@fedoraproject.org>
|
|
Date: Mon, 12 May 2025 18:21:22 +0530
|
|
Subject: [PATCH 06/33] migration: write zero pages when postcopy enabled
|
|
|
|
RH-Author: Prasad Pandit <None>
|
|
RH-MergeRequest: 390: migration: allow to enable multifd+postcopy features together, but use multifd during precopy only
|
|
RH-Jira: RHEL-59697
|
|
RH-Acked-by: Juraj Marcin <None>
|
|
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
|
|
RH-Commit: [6/11] 28ab95cd8a382d400d28511b0bb2e1ea1fd21c0a (pjp/cs-qemu-kvm)
|
|
|
|
During multifd migration, zero pages are written if
|
|
they are migrated more than once.
|
|
|
|
This may result in a migration thread hang issue when
|
|
multifd and postcopy are enabled together.
|
|
|
|
When postcopy is enabled, always write zero pages as and
|
|
when they are migrated.
|
|
|
|
Jira: https://issues.redhat.com/browse/RHEL-59697
|
|
Signed-off-by: Prasad Pandit <pjp@fedoraproject.org>
|
|
Reviewed-by: Fabiano Rosas <farosas@suse.de>
|
|
Link: https://lore.kernel.org/r/20250512125124.147064-2-ppandit@redhat.com
|
|
Signed-off-by: Peter Xu <peterx@redhat.com>
|
|
(cherry picked from commit 249543d0c02d7645b8bcda552dad138769e96831)
|
|
Signed-off-by: Prasad Pandit <ppandit@redhat.com>
|
|
---
|
|
migration/multifd-zero-page.c | 22 ++++++++++++++++++++--
|
|
1 file changed, 20 insertions(+), 2 deletions(-)
|
|
|
|
diff --git a/migration/multifd-zero-page.c b/migration/multifd-zero-page.c
|
|
index f1e988a959..3e0a04f2b5 100644
|
|
--- a/migration/multifd-zero-page.c
|
|
+++ b/migration/multifd-zero-page.c
|
|
@@ -85,9 +85,27 @@ void multifd_recv_zero_page_process(MultiFDRecvParams *p)
|
|
{
|
|
for (int i = 0; i < p->zero_num; i++) {
|
|
void *page = p->host + p->zero[i];
|
|
- if (ramblock_recv_bitmap_test_byte_offset(p->block, p->zero[i])) {
|
|
+ bool received =
|
|
+ ramblock_recv_bitmap_test_byte_offset(p->block, p->zero[i]);
|
|
+
|
|
+ /*
|
|
+ * During multifd migration zero page is written to the memory
|
|
+ * only if it is migrated more than once.
|
|
+ *
|
|
+ * It becomes a problem when both multifd & postcopy options are
|
|
+ * enabled. If the zero page which was skipped during multifd phase,
|
|
+ * is accessed during the postcopy phase of the migration, a page
|
|
+ * fault occurs. But this page fault is not served because the
|
|
+ * 'receivedmap' says the zero page is already received. Thus the
|
|
+ * thread accessing that page may hang.
|
|
+ *
|
|
+ * When postcopy is enabled, always write the zero page as and when
|
|
+ * it is migrated.
|
|
+ */
|
|
+ if (migrate_postcopy_ram() || received) {
|
|
memset(page, 0, multifd_ram_page_size());
|
|
- } else {
|
|
+ }
|
|
+ if (!received) {
|
|
ramblock_recv_bitmap_set_offset(p->block, p->zero[i]);
|
|
}
|
|
}
|
|
--
|
|
2.39.3
|
|
|