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Re: [Qemu-devel] [PATCH 5/5] migration: disable RDMA WRITR after postcop
From: |
Dr. David Alan Gilbert |
Subject: |
Re: [Qemu-devel] [PATCH 5/5] migration: disable RDMA WRITR after postcopy started. |
Date: |
Thu, 12 Apr 2018 19:55:58 +0100 |
User-agent: |
Mutt/1.9.4 (2018-02-28) |
* 858585 jemmy (address@hidden) wrote:
> On Wed, Apr 11, 2018 at 11:56 PM, Dr. David Alan Gilbert
> <address@hidden> wrote:
> > * Lidong Chen (address@hidden) wrote:
> >> RDMA write operations are performed with no notification to the destination
> >> qemu, then the destination qemu can not wakeup. So disable RDMA WRITE after
> >> postcopy started.
> >>
> >> Signed-off-by: Lidong Chen <address@hidden>
> >
> > This patch needs to be near the beginning of the series; at the moment a
> > bisect would lead you to the middle of the series which had return
> > paths, but then would fail to work properly because it would try and use
> > the RDMA code.
>
> I will fix this problem in next version.
>
> >
> >> ---
> >> migration/qemu-file.c | 3 ++-
> >> migration/rdma.c | 12 ++++++++++++
> >> 2 files changed, 14 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/migration/qemu-file.c b/migration/qemu-file.c
> >> index 8acb574..a64ac3a 100644
> >> --- a/migration/qemu-file.c
> >> +++ b/migration/qemu-file.c
> >> @@ -260,7 +260,8 @@ size_t ram_control_save_page(QEMUFile *f, ram_addr_t
> >> block_offset,
> >> int ret = f->hooks->save_page(f, f->opaque, block_offset,
> >> offset, size, bytes_sent);
> >> f->bytes_xfer += size;
> >> - if (ret != RAM_SAVE_CONTROL_DELAYED) {
> >> + if (ret != RAM_SAVE_CONTROL_DELAYED &&
> >> + ret != RAM_SAVE_CONTROL_NOT_SUPP) {
> >
> > What about f->bytes_xfer in this case?
>
> f->bytes_xfer should not update when RAM_SAVE_CONTROL_NOT_SUPP.
> I will fix this problem in next version.
>
> >
> > Is there anything we have to do at the switchover into postcopy to make
> > sure that all pages have been received?
>
> ram_save_iterate invoke ram_control_after_iterate(f, RAM_CONTROL_ROUND),
> so before next iteration which switchover into postcopy, all the pages
> sent by previous
> iteration have been received.
OK, great.
Dave
> >
> > Dave
> >
> >> if (bytes_sent && *bytes_sent > 0) {
> >> qemu_update_position(f, *bytes_sent);
> >> } else if (ret < 0) {
> >> diff --git a/migration/rdma.c b/migration/rdma.c
> >> index 81be482..8529ddd 100644
> >> --- a/migration/rdma.c
> >> +++ b/migration/rdma.c
> >> @@ -2964,6 +2964,10 @@ static size_t qemu_rdma_save_page(QEMUFile *f, void
> >> *opaque,
> >>
> >> CHECK_ERROR_STATE();
> >>
> >> + if (migrate_get_current()->state == MIGRATION_STATUS_POSTCOPY_ACTIVE)
> >> {
> >> + return RAM_SAVE_CONTROL_NOT_SUPP;
> >> + }
> >> +
> >> qemu_fflush(f);
> >>
> >> if (size > 0) {
> >> @@ -3528,6 +3532,10 @@ static int qemu_rdma_registration_start(QEMUFile
> >> *f, void *opaque,
> >>
> >> CHECK_ERROR_STATE();
> >>
> >> + if (migrate_get_current()->state == MIGRATION_STATUS_POSTCOPY_ACTIVE)
> >> {
> >> + return 0;
> >> + }
> >> +
> >> trace_qemu_rdma_registration_start(flags);
> >> qemu_put_be64(f, RAM_SAVE_FLAG_HOOK);
> >> qemu_fflush(f);
> >> @@ -3550,6 +3558,10 @@ static int qemu_rdma_registration_stop(QEMUFile *f,
> >> void *opaque,
> >>
> >> CHECK_ERROR_STATE();
> >>
> >> + if (migrate_get_current()->state == MIGRATION_STATUS_POSTCOPY_ACTIVE)
> >> {
> >> + return 0;
> >> + }
> >> +
> >> qemu_fflush(f);
> >> ret = qemu_rdma_drain_cq(f, rdma);
> >>
> >> --
> >> 1.8.3.1
> >>
> > --
> > Dr. David Alan Gilbert / address@hidden / Manchester, UK
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK
- Re: [Qemu-devel] [PATCH 2/5] migration: add the interface to set get_return_path, (continued)
[Qemu-devel] [PATCH 3/5] migration: implement the get_return_path for RDMA iochannel, Lidong Chen, 2018/04/07
[Qemu-devel] [PATCH 4/5] migration: fix qemu carsh when RDMA live migration, Lidong Chen, 2018/04/07
[Qemu-devel] [PATCH 5/5] migration: disable RDMA WRITR after postcopy started., Lidong Chen, 2018/04/07
Re: [Qemu-devel] [PATCH 0/5] Enable postcopy RDMA live migration, 858585 jemmy, 2018/04/08
Re: [Qemu-devel] [PATCH 0/5] Enable postcopy RDMA live migration, Dr. David Alan Gilbert, 2018/04/11