From: Catalin Marinas <catalin.marinas@arm.com>
To: "Aneesh Kumar K.V (Arm)" <aneesh.kumar@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, iommu@lists.linux.dev,
Will Deacon <will@kernel.org>,
Marek Szyprowski <m.szyprowski@samsung.com>,
Robin Murphy <robin.murphy@arm.com>,
suzuki.poulose@arm.com, steven.price@arm.com
Subject: Re: [PATCH] arm64: swiotlb: Don’t shrink default buffer when bounce is forced
Date: Wed, 4 Feb 2026 18:52:47 +0000 [thread overview]
Message-ID: <aYOVf066Fdr9L-nw@arm.com> (raw)
In-Reply-To: <20260120070102.182977-1-aneesh.kumar@kernel.org>
On Tue, Jan 20, 2026 at 12:31:02PM +0530, Aneesh Kumar K.V (Arm) wrote:
> arm64 reduces the default swiotlb size (for unaligned kmalloc()
> bouncing) when it detects that no swiotlb bouncing is needed.
>
> If swiotlb bouncing is explicitly forced via the command line
> (swiotlb=force), this heuristic must not apply. Add a swiotlb helper to
> query the forced-bounce state and use it to skip the resize when
> bouncing is forced.
I think the logic you proposed in reply to Robin might work better but
have you actually hit a problem that triggered this patch? Do people
passing swiotlb=force expect a specific size for the buffer?
--
Catalin
next prev parent reply other threads:[~2026-02-04 18:53 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-20 7:01 [PATCH] arm64: swiotlb: Don’t shrink default buffer when bounce is forced Aneesh Kumar K.V (Arm)
2026-01-20 9:25 ` Anshuman Khandual
2026-01-20 13:20 ` Robin Murphy
2026-01-21 6:10 ` Aneesh Kumar K.V
2026-02-04 18:52 ` Catalin Marinas [this message]
2026-02-06 6:11 ` Aneesh Kumar K.V
2026-03-04 10:00 ` Marek Szyprowski
2026-03-17 5:29 ` Aneesh Kumar K.V
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