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84 lines
2.8 KiB
84 lines
2.8 KiB
2 years ago
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From 2516a21205e67078cb735e9fd47ba50156c166b7 Mon Sep 17 00:00:00 2001
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From: Leonardo Bras <leobras@redhat.com>
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Date: Mon, 11 Jul 2022 18:11:13 -0300
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Subject: [PATCH 5/9] migration/multifd: Report to user when zerocopy not
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working
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MIME-Version: 1.0
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Content-Type: text/plain; charset=UTF-8
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Content-Transfer-Encoding: 8bit
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RH-Author: Leonardo Brás <leobras@redhat.com>
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RH-MergeRequest: 201: Zero-copy-send fixes + improvements
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RH-Commit: [5/8] 0b2e23b7f8ae72936e11369cd44ba474ef3b9e8c
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RH-Bugzilla: 2110203
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RH-Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
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RH-Acked-by: Peter Xu <peterx@redhat.com>
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RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
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Some errors, like the lack of Scatter-Gather support by the network
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interface(NETIF_F_SG) may cause sendmsg(...,MSG_ZEROCOPY) to fail on using
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zero-copy, which causes it to fall back to the default copying mechanism.
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After each full dirty-bitmap scan there should be a zero-copy flush
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happening, which checks for errors each of the previous calls to
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sendmsg(...,MSG_ZEROCOPY). If all of them failed to use zero-copy, then
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increment dirty_sync_missed_zero_copy migration stat to let the user know
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about it.
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Signed-off-by: Leonardo Bras <leobras@redhat.com>
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Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
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Acked-by: Peter Xu <peterx@redhat.com>
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Message-Id: <20220711211112.18951-4-leobras@redhat.com>
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Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
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(cherry picked from commit d59c40cc483729f2e67c80e58df769ad19976fe9)
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Signed-off-by: Leonardo Bras <leobras@redhat.com>
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---
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migration/multifd.c | 2 ++
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migration/ram.c | 5 +++++
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migration/ram.h | 2 ++
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3 files changed, 9 insertions(+)
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diff --git a/migration/multifd.c b/migration/multifd.c
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index 90ab4c4346..7c16523e6b 100644
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--- a/migration/multifd.c
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+++ b/migration/multifd.c
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@@ -631,6 +631,8 @@ int multifd_send_sync_main(QEMUFile *f)
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if (ret < 0) {
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error_report_err(err);
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return -1;
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+ } else if (ret == 1) {
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+ dirty_sync_missed_zero_copy();
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}
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}
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}
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diff --git a/migration/ram.c b/migration/ram.c
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index e7173da217..93cdb456ac 100644
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--- a/migration/ram.c
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+++ b/migration/ram.c
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@@ -403,6 +403,11 @@ static void ram_transferred_add(uint64_t bytes)
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ram_counters.transferred += bytes;
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}
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+void dirty_sync_missed_zero_copy(void)
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+{
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+ ram_counters.dirty_sync_missed_zero_copy++;
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+}
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+
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/* used by the search for pages to send */
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struct PageSearchStatus {
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/* Current block being searched */
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diff --git a/migration/ram.h b/migration/ram.h
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index c515396a9a..69c3ccb26a 100644
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--- a/migration/ram.h
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+++ b/migration/ram.h
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@@ -88,4 +88,6 @@ void ram_write_tracking_prepare(void);
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int ram_write_tracking_start(void);
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void ram_write_tracking_stop(void);
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+void dirty_sync_missed_zero_copy(void);
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+
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#endif
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--
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2.31.1
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