From: "Tan, Jianfeng" <jianfeng.tan@intel.com>
To: Stephen Hemminger <stephen@networkplumber.org>,
"dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] [RFC] pci: force address of mappings in secondary process
Date: Tue, 11 Jul 2017 01:56:15 +0000 [thread overview]
Message-ID: <ED26CBA2FAD1BF48A8719AEF02201E365122F647@SHSMSX103.ccr.corp.intel.com> (raw)
In-Reply-To: <20170711011242.4606-1-stephen@networkplumber.org>
> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Stephen
> Hemminger
> Sent: Tuesday, July 11, 2017 9:13 AM
> To: dev@dpdk.org
> Cc: Stephen Hemminger
> Subject: [dpdk-dev] [RFC] pci: force address of mappings in secondary
> process
>
> The PCI memory resources in the secondary process should be in
> the exact same location as the primary process. Otherwise
> there is a risk of a stray pointer.
>
> Not sure if this is right, but it looks like a potential
> problem.
>
> ---
> lib/librte_eal/common/eal_common_pci_uio.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/lib/librte_eal/common/eal_common_pci_uio.c
> b/lib/librte_eal/common/eal_common_pci_uio.c
> index 367a6816dcb8..2156b1a436c4 100644
> --- a/lib/librte_eal/common/eal_common_pci_uio.c
> +++ b/lib/librte_eal/common/eal_common_pci_uio.c
> @@ -77,7 +77,7 @@ pci_uio_map_secondary(struct rte_pci_device *dev)
>
> void *mapaddr = pci_map_resource(uio_res-
> >maps[i].addr,
> fd, (off_t)uio_res->maps[i].offset,
> - (size_t)uio_res->maps[i].size, 0);
> + (size_t)uio_res->maps[i].size,
> MAP_FIXED);
> /* fd is not needed in slave process, close it */
> close(fd);
> if (mapaddr != uio_res->maps[i].addr) {
> --
> 2.11.0
+1 for this RFC. I also once encounter such problem, and I use the same way to solve it. The addr parameter of mmap() syscall is only a hint instead of a must even the VMA is not occupied yet.
Thanks,
Jianfeng
next prev parent reply other threads:[~2017-07-11 1:56 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-11 1:12 Stephen Hemminger
2017-07-11 1:56 ` Tan, Jianfeng [this message]
2017-07-11 11:35 ` Sergio Gonzalez Monroy
2017-07-11 20:00 ` Stephen Hemminger
2017-07-12 7:24 ` Sergio Gonzalez Monroy
2017-07-12 2:45 ` Tan, Jianfeng
2017-07-12 7:31 ` Sergio Gonzalez Monroy
2017-07-12 8:58 ` Tan, Jianfeng
2019-01-23 19:21 ` Ferruh Yigit
2019-01-23 20:37 ` Stephen Hemminger
2019-01-28 9:59 ` Burakov, Anatoly
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=ED26CBA2FAD1BF48A8719AEF02201E365122F647@SHSMSX103.ccr.corp.intel.com \
--to=jianfeng.tan@intel.com \
--cc=dev@dpdk.org \
--cc=stephen@networkplumber.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).