From: Alex Williamson <alex.williamson@redhat.com>
To: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
acme@kernel.org, andihartmann@freenet.de, mingo@redhat.com,
bp@alien8.de
Subject: Re: [PATCH V4 5/6] perf/amd/iommu: Enable support for multiple IOMMUs
Date: Mon, 22 Feb 2016 22:24:57 -0700 [thread overview]
Message-ID: <20160222222457.2824f7e0@t450s.home> (raw)
In-Reply-To: <56CBEA4A.8070001@amd.com>
On Tue, 23 Feb 2016 12:12:42 +0700
Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com> wrote:
> Hi
>
> On 02/22/2016 09:07 PM, Peter Zijlstra wrote:
> > On Mon, Feb 22, 2016 at 03:00:31PM +0700, Suravee Suthikulpanit wrote:
> >>> So I really don't have time to review new muck while I'm hunting perf
> >>> core fail, but Boris made me look at this.
> >>>
> >>> This is crazy, if you have multiple IOMMUs then create an event per
> >>> IOMMU, do _NOT_ fold them all into a single event.
> >>
> >> These are system-wide events, which are programmed on every IOMMU the same
> >> way. I am not sure what you meant by creating an event per IOMMU. Do you
> >> mean I should create internal per-IOMMU struct perf_event for each event?
> >
> > No, I meant to expose each IOMMU individually to userspace, as a
> > separate device.
> >
> > Is there never a case to profile just one of the IOMMUs ?
> >
>
> I see. That's definitely doable and simpler to implement.
>
> I was not sure if making users specify the IOMMU instance (e.g.
> amd_iommu_0/<ev name> , amd_iommu_1/<ev_name>, ....) would be too
> tedious. However, this would actually give users better control of the
> performance events, which is a good trade-off. I think it is acceptable.
>
> I'll make the change and send this out in V5.
We already expose individual IOMMU hardware units in /sys/class/iommu/,
you might consider trying to match the names there for the convenience
of the user. Looks like we use ivhd%d for AMD. Thanks,
Alex
next prev parent reply other threads:[~2016-02-23 5:25 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-11 9:15 [PATCH V4 0/6] perf/amd/iommu: Enable multi-IOMMU support Suravee Suthikulpanit
2016-02-11 9:15 ` [PATCH V4 1/6] perf/amd/iommu: Consolidate and move perf_event_amd_iommu header Suravee Suthikulpanit
2016-02-11 9:15 ` [PATCH V4 2/6] perf/amd/iommu: Modify functions to query max banks and counters Suravee Suthikulpanit
2016-02-18 11:11 ` Borislav Petkov
2016-02-22 4:55 ` Suravee Suthikulpanit
2016-02-11 9:15 ` [PATCH V4 3/6] iommu/amd: Introduce amd_iommu_get_num_iommus() Suravee Suthikulpanit
2016-02-11 9:15 ` [PATCH V4 4/6] perf/amd/iommu: Introduce get_iommu_bnk_cnt_evt_idx Suravee Suthikulpanit
2016-02-18 11:45 ` Borislav Petkov
2016-02-11 9:15 ` [PATCH V4 5/6] perf/amd/iommu: Enable support for multiple IOMMUs Suravee Suthikulpanit
2016-02-18 13:18 ` Peter Zijlstra
2016-02-22 8:00 ` Suravee Suthikulpanit
2016-02-22 14:07 ` Peter Zijlstra
2016-02-23 5:12 ` Suravee Suthikulpanit
2016-02-23 5:24 ` Alex Williamson [this message]
2016-02-23 9:56 ` Suravee Suthikulpanit
2016-02-18 13:21 ` Borislav Petkov
2016-02-11 9:15 ` [PATCH V4 6/6] perf/amd/iommu: Clean up print messages pr_debug Suravee Suthikulpanit
2016-02-18 13:22 ` Borislav Petkov
2016-02-18 2:30 ` [PATCH V4 0/6] perf/amd/iommu: Enable multi-IOMMU support Suravee Suthikulpanit
2016-02-23 11:04 ` Joerg Roedel
2016-02-23 11:27 ` Suravee Suthikulpanit
2016-02-23 11:39 ` Suravee Suthikulpanit
2016-02-23 12:12 ` [PATCH] iommu/amd: Fix boot warning when device 00:00.0 is not iommu Joerg Roedel
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=20160222222457.2824f7e0@t450s.home \
--to=alex.williamson@redhat.com \
--cc=Suravee.Suthikulpanit@amd.com \
--cc=acme@kernel.org \
--cc=andihartmann@freenet.de \
--cc=bp@alien8.de \
--cc=iommu@lists.linux-foundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=peterz@infradead.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).