On Mon, Feb 05, 2024 at 03:32:41PM +0000, Robin Murphy wrote:
> From: Pasha Tatashin <pasha.tatashin@xxxxxxxxxx>
>
> The magazine buffers can take gigabytes of kmem memory, dominating all
> other allocations. For observability purpose create named slab cache so
> the iova magazine memory overhead can be clearly observed.
>
> With this change:
>
> > slabtop -o | head
> Active / Total Objects (% used) : 869731 / 952904 (91.3%)
> Active / Total Slabs (% used) : 103411 / 103974 (99.5%)
> Active / Total Caches (% used) : 135 / 211 (64.0%)
> Active / Total Size (% used) : 395389.68K / 411430.20K (96.1%)
> Minimum / Average / Maximum Object : 0.02K / 0.43K / 8.00K
>
> OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME
> 244412 244239 99% 1.00K 61103 4 244412K iommu_iova_magazine
> 91636 88343 96% 0.03K 739 124 2956K kmalloc-32
> 75744 74844 98% 0.12K 2367 32 9468K kernfs_node_cache
>
> On this machine it is now clear that magazine use 242M of kmem memory.
>
> Acked-by: David Rientjes <rientjes@xxxxxxxxxx>
> Signed-off-by: Pasha Tatashin <pasha.tatashin@xxxxxxxxxx>
> [ rm: adjust to rework of iova_cache_{get,put} ]
> Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx>
> ---
Reviewed-by: Jerry Snitselaar <jsnitsel@xxxxxxxxxx>
