Re: [PATCH 3/3] xfs: rework zone GC buffer management

Damien Le Moal
2025-12-18T07:12:23Z

On 12/18/25 15:31, Christoph Hellwig wrote:
> The double buffering where just one scratch area is used at a time does
> not efficiently use the available memory. It was originally implemented
> when GC I/O could happen out of order, but that was removed before
> upstream submission to avoid fragmentation. Now that all GC I/Os are
> processed in order, just use a number of buffers as a simple ring buffer.
>
> For a synthetic benchmark that fills 256MiB HDD zones and punches out
> holes to free half the space this leads to a decrease of GC time by
> a little more than 25%.
>
> Thanks to Hans Holmberg <hans.holmberg@wdc.com> for testing and
> benchmarking.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Looks good.

Reviewed-by: Damien Le Moal <dlemoal@kernel.org>

--
Damien Le Moal
Western Digital Research