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Re: [Qemu-devel] [PATCH 11/29] memory: include DIRTY_MEMORY_MIGRATION in
From: |
Fam Zheng |
Subject: |
Re: [Qemu-devel] [PATCH 11/29] memory: include DIRTY_MEMORY_MIGRATION in the dirty log mask |
Date: |
Tue, 26 May 2015 16:40:31 +0800 |
User-agent: |
Mutt/1.5.23 (2014-03-12) |
On Mon, 04/27 18:28, Paolo Bonzini wrote:
> The separate handling of DIRTY_MEMORY_MIGRATION, which does not
> call log_start/log_stop callbacks when it changes in a region's
> dirty logging mask, has caused several bugs.
>
> One recent example is commit 4cc856f (kvm-all: Sync dirty-bitmap from
> kvm before kvm destroy the corresponding dirty_bitmap, 2015-04-02).
> Another performance problem is that KVM keeps tracking dirty pages
> after a failed live migration, which causes bad performance due to
> disallowing huge page mapping.
>
> This patch removes the root cause of the problem by reporting
> DIRTY_MEMORY_MIGRATION changes via log_start and log_stop.
> Note that we now have to rebuild the FlatView when global dirty
> logging is enabled or disabled; this ensures that log_start and
> log_stop callbacks are invoked.
>
> This will also be used to make the setting of bitmaps conditional.
>
> Signed-off-by: Paolo Bonzini <address@hidden>
> ---
> memory.c | 18 ++++++++++++++++--
> 1 file changed, 16 insertions(+), 2 deletions(-)
>
> diff --git a/memory.c b/memory.c
> index 1966347..174cd15 100644
> --- a/memory.c
> +++ b/memory.c
> @@ -537,7 +537,7 @@ static void render_memory_region(FlatView *view,
> remain = clip.size;
>
> fr.mr = mr;
> - fr.dirty_log_mask = mr->dirty_log_mask;
> + fr.dirty_log_mask = memory_region_get_dirty_log_mask(mr);
> fr.romd_mode = mr->romd_mode;
> fr.readonly = readonly;
>
> @@ -1329,7 +1329,11 @@ bool memory_region_is_skip_dump(MemoryRegion *mr)
>
> uint8_t memory_region_get_dirty_log_mask(MemoryRegion *mr)
> {
> - return mr->dirty_log_mask;
> + uint8_t mask = mr->dirty_log_mask;
> + if (global_dirty_log) {
> + mask |= (1 << DIRTY_MEMORY_MIGRATION);
This is ugly, but I don't know how to do differently. :(
> + }
> + return mask;
> }
>
> bool memory_region_is_logging(MemoryRegion *mr, uint8_t client)
> @@ -1892,10 +1896,20 @@ void memory_global_dirty_log_start(void)
> {
> global_dirty_log = true;
> MEMORY_LISTENER_CALL_GLOBAL(log_global_start, Forward);
> +
> + /* Refresh DIRTY_LOG_MIGRATION bit. */
> + memory_region_transaction_begin();
> + memory_region_update_pending = true;
> + memory_region_transaction_commit();
> }
>
> void memory_global_dirty_log_stop(void)
> {
> + /* Refresh DIRTY_LOG_MIGRATION bit. */
> + memory_region_transaction_begin();
> + memory_region_update_pending = true;
> + memory_region_transaction_commit();
> +
> global_dirty_log = false;
Shouldn't this go before memory_region_transaction_begin?
Fam
- Re: [Qemu-devel] [PATCH 11/29] memory: include DIRTY_MEMORY_MIGRATION in the dirty log mask,
Fam Zheng <=