From: Chris Wilson <chris@chris-wilson.co.uk>
To: Ashutosh Dixit <ashutosh.dixit@intel.com>,
intel-gfx@lists.freedesktop.org
Subject: Re: [Intel-gfx] [PATCH] drm/i915/perf: Do not clear pollin for small user read buffers
Date: Fri, 03 Apr 2020 17:17:14 +0100 [thread overview]
Message-ID: <158593063457.5852.4620122096592068466@build.alporthouse.com> (raw)
In-Reply-To: <20200403010120.3067-1-ashutosh.dixit@intel.com>
Quoting Ashutosh Dixit (2020-04-03 02:01:20)
> It is wrong to block the user thread in the next poll when OA data is
> already available which could not fit in the user buffer provided in
> the previous read. In several cases the exact user buffer size is not
> known. Blocking user space in poll can lead to data loss when the
> buffer size used is smaller than the available data.
>
> This change fixes this issue and allows user space to read all OA data
> even when using a buffer size smaller than the available data using
> multiple non-blocking reads rather than staying blocked in poll till
> the next timer interrupt.
>
> v2: Fix ret value for blocking reads (Umesh)
> v3: Mistake during patch send (Ashutosh)
> v4: Remove -EAGAIN from comment (Umesh)
> v5: Improve condition for clearing pollin and return (Lionel)
> v6: Improve blocking read loop and other cleanups (Lionel)
> v7: Added Cc stable
>
> Cc: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
> Cc: <stable@vger.kernel.org>
> Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
> Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Did you manage to devise a test case? It is nice (some might say
important) to pair a patch for stable with its regression test.
-Chris
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
next prev parent reply other threads:[~2020-04-03 16:17 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-03 1:01 [Intel-gfx] [PATCH] drm/i915/perf: Do not clear pollin for small user read buffers Ashutosh Dixit
2020-04-03 1:47 ` [Intel-gfx] ✓ Fi.CI.BAT: success for drm/i915/perf: Do not clear pollin for small user read buffers (rev7) Patchwork
2020-04-03 16:11 ` [Intel-gfx] ✗ Fi.CI.IGT: failure " Patchwork
2020-04-03 16:17 ` Chris Wilson [this message]
2020-04-03 17:45 ` [Intel-gfx] [PATCH] drm/i915/perf: Do not clear pollin for small user read buffers Dixit, Ashutosh
2020-04-03 17:59 ` Chris Wilson
-- strict thread matches above, loose matches on Subject: below --
2020-04-08 23:42 Ashutosh Dixit
2020-04-13 22:05 ` Rodrigo Vivi
2020-03-31 23:14 Ashutosh Dixit
2020-04-01 6:57 ` Lionel Landwerlin
2020-04-01 7:43 ` Dixit, Ashutosh
2020-04-01 7:51 ` Lionel Landwerlin
2020-03-31 5:22 Ashutosh Dixit
2020-03-31 7:34 ` Lionel Landwerlin
2020-03-31 23:29 ` Dixit, Ashutosh
2020-03-27 23:16 Ashutosh Dixit
2020-03-30 8:23 ` Lionel Landwerlin
2020-03-31 5:47 ` Dixit, Ashutosh
2020-03-27 23:11 Ashutosh Dixit
2020-03-26 4:43 Ashutosh Dixit
2020-03-26 9:09 ` Lionel Landwerlin
2020-03-27 3:39 ` Dixit, Ashutosh
2020-03-25 18:20 Ashutosh Dixit
2020-03-25 19:25 ` Lionel Landwerlin
2020-03-25 20:44 ` Dixit, Ashutosh
2020-03-26 0:32 ` Umesh Nerlige Ramappa
2020-03-26 1:52 ` Dixit, Ashutosh
2020-03-26 18:02 ` Umesh Nerlige Ramappa
2020-03-27 1:28 ` Dixit, Ashutosh
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=158593063457.5852.4620122096592068466@build.alporthouse.com \
--to=chris@chris-wilson.co.uk \
--cc=ashutosh.dixit@intel.com \
--cc=intel-gfx@lists.freedesktop.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).