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From: Dan Siemon <dan@coverfire.com>
To: Xdp <xdp-newbies@vger.kernel.org>
Subject: Umem Questions
Date: Fri, 14 May 2021 10:34:01 -0400	[thread overview]
Message-ID: <c276e6d316beedd47f791aed0453aa181619edaf.camel@coverfire.com> (raw)

I've been trying to work with large Umem areas and have a few questions
. I'd appreciate any help or pointers. If it makes any difference, my
AF_XDP testing is with i40e.

1) I use kernel args to reserve huge pages on boot. The application
mmap call with the huge TLB flag appears to use huge pages as I can see
the count of used huge pages go up (/proc/meminfo). However, the number
of pages used by the umem, as shown in ss output, looks to still be 4k
pages. Are there plans to support huge pages in Umem? How hard would
this be?

2) It looks like there is a limit of 2GB on the maximum Umem size? I've
tried with and without huge pages. Is this fundamental? How hard would
it be to increase this?

For both of these, I'd like to try to help make them happen. If the
kernel side changes are deep or large, it may be beyond me but I can
offer lab equipment and testing.

Thanks.


             reply	other threads:[~2021-05-14 14:34 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-14 14:34 Dan Siemon [this message]
2021-05-17  8:21 ` Umem Questions Magnus Karlsson
2021-05-19 21:09   ` Dan Siemon
2021-05-20  6:14     ` Magnus Karlsson
2021-05-20 12:40       ` Magnus Karlsson
2021-05-20 12:50         ` Magnus Karlsson
2021-05-21 18:17           ` Dan Siemon

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