svn commit: r348117 - head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs

[Slawa Olhovchenkov]

On Wed, May 22, 2019 at 06:43:48PM +0000, Alexander Motin wrote:

> Author: mav
> Date: Wed May 22 18:43:48 2019
> New Revision: 348117
> URL: https://svnweb.freebsd.org/changeset/base/348117
> 
> Log:
>   Allocate buffers smaller then ABD chunk size as linear.
>   
>   This allows to reduce memory waste by letting UMA to put multiple small
>   buffers into one memory page slab.  The page sharing means that UMA
>   may not be able to free memory page when some of buffers are freed, but
>   alternatively memory used by that buffer would just be wasted from the
>   beginning.
>   
>   This change follows alike change in ZoL, but unlike Linux (according to
>   my understanding of it from comments) FreeBSD never shares slabs bigger
>   then one memory page, so this should be even less invasive then there.
>   
>   MFC after:	2 weeks
>   Sponsored by:	iXsystems, Inc.
> 
> Modified:
>   head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/abd.c
> 
> Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/abd.c
> ==============================================================================
> --- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/abd.c	Wed May 22 17:42:22 2019	(r348116)
> +++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/abd.c	Wed May 22 18:43:48 2019	(r348117)
> @@ -290,7 +290,7 @@ abd_free_struct(abd_t *abd)
>  abd_t *
>  abd_alloc(size_t size, boolean_t is_metadata)
>  {
> -	if (!zfs_abd_scatter_enabled)
> +	if (!zfs_abd_scatter_enabled || size <= zfs_abd_chunk_size)
>  		return (abd_alloc_linear(size, is_metadata));

may be `size < zfs_abd_chunk_size`?

>  	VERIFY3U(size, <=, SPA_MAXBLOCKSIZE);
> _______________________________________________
> svn-src-all at freebsd.org mailing list
> https://lists.freebsd.org/mailman/listinfo/svn-src-all
> To unsubscribe, send any mail to "svn-src-all-unsubscribe at freebsd.org"