From: Peter Zijlstra <peterz@infradead.org>
To: Kim Phillips <kim.phillips@amd.com>
Cc: Ingo Molnar <mingo@kernel.org>,
linux-kernel@vger.kernel.org,
Stephane Eranian <eranian@google.com>,
Ingo Molnar <mingo@redhat.com>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Borislav Petkov <bp@alien8.de>, "H. Peter Anvin" <hpa@zytor.com>,
x86@kernel.org, stable@vger.kernel.org
Subject: Re: [PATCH] perf/x86/amd/ibs: Fix sample bias for dispatched micro-ops
Date: Wed, 28 Aug 2019 10:02:59 +0200 [thread overview]
Message-ID: <20190828080259.GM2332@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20190826195730.30614-1-kim.phillips@amd.com>
On Mon, Aug 26, 2019 at 02:57:30PM -0500, Kim Phillips wrote:
> diff --git a/arch/x86/events/amd/ibs.c b/arch/x86/events/amd/ibs.c
> index 62f317c9113a..f2625b4a5a8b 100644
> --- a/arch/x86/events/amd/ibs.c
> +++ b/arch/x86/events/amd/ibs.c
> @@ -663,8 +663,15 @@ static int perf_ibs_handle_irq(struct perf_ibs *perf_ibs, struct pt_regs *iregs)
> out:
> if (throttle)
> perf_ibs_stop(event, 0);
> - else
> - perf_ibs_enable_event(perf_ibs, hwc, period >> 4);
> + else {
Coding Style requires braces on both legs of a conditional.
> + period >>= 4;
> +
> + if ((ibs_caps & IBS_CAPS_RDWROPCNT) &&
> + (*config & IBS_OP_CNT_CTL))
> + period |= *config & IBS_OP_CUR_CNT_RAND;
> +
> + perf_ibs_enable_event(perf_ibs, hwc, period);
> + }
>
> perf_event_update_userpage(event);
>
> diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h
> index 1392d5e6e8d6..67d94696a1d6 100644
> --- a/arch/x86/include/asm/perf_event.h
> +++ b/arch/x86/include/asm/perf_event.h
> @@ -259,9 +259,12 @@ struct pebs_lbr {
> #define IBS_FETCH_CNT 0xFFFF0000ULL
> #define IBS_FETCH_MAX_CNT 0x0000FFFFULL
>
> -/* ibs op bits/masks */
> -/* lower 4 bits of the current count are ignored: */
> -#define IBS_OP_CUR_CNT (0xFFFF0ULL<<32)
> +/* ibs op bits/masks
> + * The lower 7 bits of the current count are random bits
> + * preloaded by hardware and ignored in software
> + */
Malformed comment style.
> +#define IBS_OP_CUR_CNT (0xFFF80ULL<<32)
> +#define IBS_OP_CUR_CNT_RAND (0x0007FULL<<32)
> #define IBS_OP_CNT_CTL (1ULL<<19)
> #define IBS_OP_VAL (1ULL<<18)
> #define IBS_OP_ENABLE (1ULL<<17)
Fixed up both issues and applied.
Thanks!
next prev parent reply other threads:[~2019-08-28 8:03 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-26 19:57 [PATCH] perf/x86/amd/ibs: Fix sample bias for dispatched micro-ops Kim Phillips
2019-08-28 8:02 ` Peter Zijlstra [this message]
2019-08-31 9:06 ` [tip: perf/urgent] " tip-bot2 for Kim Phillips
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=20190828080259.GM2332@hirez.programming.kicks-ass.net \
--to=peterz@infradead.org \
--cc=acme@kernel.org \
--cc=alexander.shishkin@linux.intel.com \
--cc=bp@alien8.de \
--cc=eranian@google.com \
--cc=hpa@zytor.com \
--cc=jolsa@redhat.com \
--cc=kim.phillips@amd.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=mingo@redhat.com \
--cc=namhyung@kernel.org \
--cc=stable@vger.kernel.org \
--cc=tglx@linutronix.de \
--cc=x86@kernel.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).