From: David Rientjes <rientjes@google.com>
To: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: robin.murphy@arm.com, joro@8bytes.org, will@kernel.org,
iommu@lists.linux.dev, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, yosryahmed@google.com
Subject: Re: [PATCH v2] iommu/iova: use named kmem_cache for iova magazines
Date: Fri, 2 Feb 2024 18:30:19 -0800 (PST) [thread overview]
Message-ID: <d506a467-8af7-dc26-709a-ba49e6c5a3a6@google.com> (raw)
In-Reply-To: <20240202192820.536408-1-pasha.tatashin@soleen.com>
On Fri, 2 Feb 2024, Pasha Tatashin wrote:
> 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.
>
> Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Very impressive!
Acked-by: David Rientjes <rientjes@google.com>
next prev parent reply other threads:[~2024-02-03 2:30 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-02 19:28 Pasha Tatashin
2024-02-03 2:30 ` David Rientjes [this message]
2024-02-05 15:31 ` Robin Murphy
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