After testing, I think you are right.
Will remove the cpu_throttle_stop() in V4.
Thanks,
Lei.
-----Original Message-----
From: Dr. David Alan Gilbert <dgilb...@redhat.com>
Sent: Thursday, March 25, 2021 12:40 AM
To: Rao, Lei <lei....@intel.com>
Cc: Zhang, Chen <chen.zh...@intel.com>; lizhij...@cn.fujitsu.com;
jasow...@redhat.com; quint...@redhat.com; pbonz...@redhat.com;
lukasstra...@web.de; qemu-devel@nongnu.org
Subject: Re: [PATCH v3 07/10] Reset the auto-converge counter at every
checkpoint.
* leirao (lei....@intel.com) wrote:
> From: "Rao, Lei" <lei....@intel.com>
>
> if we don't reset the auto-converge counter, it will continue to run
> with COLO running, and eventually the system will hang due to the CPU
> throttle reaching DEFAULT_MIGRATE_MAX_CPU_THROTTLE.
>
> Signed-off-by: Lei Rao <lei....@intel.com>
> ---
> migration/colo.c | 4 ++++
> migration/ram.c | 10 ++++++++++
> migration/ram.h | 1 +
> 3 files changed, 15 insertions(+)
>
> diff --git a/migration/colo.c b/migration/colo.c index
> 1aaf316..723ffb8 100644
> --- a/migration/colo.c
> +++ b/migration/colo.c
> @@ -459,6 +459,10 @@ static int colo_do_checkpoint_transaction(MigrationState
> *s,
> if (ret < 0) {
> goto out;
> }
> +
> + if (migrate_auto_converge()) {
> + mig_throttle_counter_reset();
> + }
> /*
> * Only save VM's live state, which not including device state.
> * TODO: We may need a timeout mechanism to prevent COLO process
> diff --git a/migration/ram.c b/migration/ram.c index 72143da..e795a8d
> 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -652,6 +652,16 @@ static void mig_throttle_guest_down(uint64_t
> bytes_dirty_period,
> }
> }
>
> +void mig_throttle_counter_reset(void) {
> + RAMState *rs = ram_state;
> +
> + rs->time_last_bitmap_sync = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
> + rs->num_dirty_pages_period = 0;
> + rs->bytes_xfer_prev = ram_counters.transferred;
> + cpu_throttle_stop();
I think this is right, so:
Reviewed-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
however, do you really need the cpu_throttle_stop? Shouldn't the previous
iteration have called that in migration_iteration_finish() ?
Dave
> +}
> +
> /**
> * xbzrle_cache_zero_page: insert a zero page in the XBZRLE cache
> *
> diff --git a/migration/ram.h b/migration/ram.h index 6378bb3..3f78175
> 100644
> --- a/migration/ram.h
> +++ b/migration/ram.h
> @@ -50,6 +50,7 @@ bool ramblock_is_ignored(RAMBlock *block); int
> xbzrle_cache_resize(uint64_t new_size, Error **errp); uint64_t
> ram_bytes_remaining(void); uint64_t ram_bytes_total(void);
> +void mig_throttle_counter_reset(void);
>
> uint64_t ram_pagesize_summary(void);
> int ram_save_queue_pages(const char *rbname, ram_addr_t start,
> ram_addr_t len);
> --
> 1.8.3.1
>
--
Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
