From: Dave Jiang <dave.jiang@intel.com>
To: Raju Rangoju <Raju.Rangoju@amd.com>, <jdmason@kudzu.us>,
<allenbh@gmail.com>, <ntb@lists.linux.dev>
Cc: Basavaraj Natikar <Basavaraj.Natikar@amd.com>
Subject: Re: ntb_perf max chunk order
Date: Tue, 16 Jan 2024 09:13:38 -0700 [thread overview]
Message-ID: <eb872f9f-03f8-4a25-a3b2-e338833a9966@intel.com> (raw)
In-Reply-To: <7739c789-109b-2aa7-73d2-db833853470c@amd.com>
On 1/16/24 00:10, Raju Rangoju wrote:
> Hi,
>
> Could you please explain why net_perf does not support larger chunk sizes? Currently only MAX_CHUNK_ORDER 20 is supported (1M and below)
It has to do with the limitation of Linux dma_alloc_coherent() call. Allocating physically (or IOVA) contiguous memory that's extremely large is difficult. In the past, you can do it with limited success up to 8MB with help from IOMMU as I recall. For experimental and testing purposes, you can try larger sizes.
>
> Thanks,
> Raju
>
next prev parent reply other threads:[~2024-01-16 16:13 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-16 7:10 ntb_perf max chunk order Raju Rangoju
2024-01-16 16:13 ` Dave Jiang [this message]
2024-01-23 18:49 ` Raju Rangoju
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