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Date: Wed, 20 Sep 2017 15:26:32 +0100
From: Stefan Hajnoczi <stefanha@redhat.com>
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References: <20170920102311.25736-1-el13635@mail.ntua.gr>
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Subject: Re: [Qemu-devel] [PATCH 1/3] block: add bdrv_co_drain_end callback
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To: Manos Pitsidianakis <el13635@mail.ntua.gr>
Cc: qemu-devel <qemu-devel@nongnu.org>, qemu-block <qemu-block@nongnu.org>, Kevin Wolf <kwolf@redhat.com>, Max Reitz <mreitz@redhat.com>, Fam Zheng <famz@redhat.com>

On Wed, Sep 20, 2017 at 01:23:09PM +0300, Manos Pitsidianakis wrote:
> @@ -188,7 +194,7 @@ static bool bdrv_drain_recurse(BlockDriverState *bs)
>      waited = BDRV_POLL_WHILE(bs, atomic_read(&bs->in_flight) > 0);
>  
>      /* Ensure any pending metadata writes are submitted to bs->file.  */
> -    bdrv_drain_invoke(bs);
> +    bdrv_drain_invoke(bs, begin);

Do you need to move bdrv_drain_invoke(bs, begin) before
BDRV_POLL_WHILE(bs, atomic_read(&bs->in_flight) > 0)?

This will ensure that throttling is disabled and the TGM restarted
before we wait for requests to complete.

Stefan