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From: Gerd Hoffmann <kraxel@redhat.com>
To: Carwyn Ellis <carwynellis@gmail.com>
Cc: qemu-trivial@nongnu.org, qemu-devel@nongnu.org
Subject: Re: [PATCH 2/2] hw/display/vmware_vga: do not discard screen updates
Date: Tue, 4 Jan 2022 13:23:50 +0100	[thread overview]
Message-ID: <20220104122350.ktsnpqfmtrmwcxrk@sirius.home.kraxel.org> (raw)
In-Reply-To: <20220104091135.61226-3-carwynellis@gmail.com>

  Hi,

> This change firstly increases the screen update FIFO size to ensure it's
> large enough to accomodate all updates deferred in a given screen
> refresh cycle.

How do you know it's large enough?

> @@ -385,7 +385,14 @@ static inline void vmsvga_update_rect_delayed(struct vmsvga_state_s *s,
>  {
>      struct vmsvga_rect_s *rect = &s->redraw_fifo[s->redraw_fifo_last++];
>  
> -    s->redraw_fifo_last &= REDRAW_FIFO_LEN - 1;
> +    if (s->redraw_fifo_last >= REDRAW_FIFO_LEN) {
> +        VMWARE_VGA_DEBUG("%s: Discarding updates - FIFO length %d exceeded\n",
> +            "vmsvga_update_rect_delayed",
> +            REDRAW_FIFO_LEN

Hmm, apparently you don't know ;)

How about just calling vmsvga_update_rect_flush()
when the fifo is (almost) full?

Which guest do you use btw?  I'm kind-of surprised this is still being
used even though it hasn't seen any development (beside fixing a bug now
and then) for a decade or so and the feature gap to recent vmware is
huge ...

take care,
  Gerd



  reply	other threads:[~2022-01-04 12:26 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-01-04  9:11 [PATCH 0/2] hw/display/vmware_vga: supress debug output and fix Carwyn Ellis
2022-01-04  9:11 ` [PATCH 1/2] hw/display/vmware_vga: only show debug output if DEBUG enabled Carwyn Ellis
2022-01-04  9:18   ` Laurent Vivier
2022-01-04  9:20     ` Carwyn Ellis
2022-01-04  9:27       ` Laurent Vivier
2022-01-04  9:28         ` Carwyn Ellis
2022-01-04  9:11 ` [PATCH 2/2] hw/display/vmware_vga: do not discard screen updates Carwyn Ellis
2022-01-04 12:23   ` Gerd Hoffmann [this message]
2022-01-04 13:17     ` Carwyn Ellis
  -- strict thread matches above, loose matches on Subject: below --
2022-01-04 18:06 [PATCH 0/2] use trace events and fix garbled output Carwyn Ellis
2022-01-04 18:06 ` [PATCH 2/2] hw/display/vmware_vga: do not discard screen updates Carwyn Ellis

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