All of lore.kernel.org
 help / color / mirror / Atom feed
From: Dan Williams <dan.j.williams@intel.com>
To: sebhtml@videotron.qc.ca
Cc: Steven Rostedt <rostedt@goodmis.org>,
	acme@redhat.com, tz.stoyanov@gmail.com,
	Namhyung Kim <namhyung@kernel.org>,
	zwisler@kernel.org, arangradient@gmail.com,
	linux-perf-users@vger.kernel.org,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH] pfn_t: force '~' to be parsed as an unary operator
Date: Mon, 22 Oct 2018 10:13:48 -0700	[thread overview]
Message-ID: <CAPcyv4iJ_bfzOtV_GAQg_tdLLuebE_1Gp420LMG0xbR2ZQdV7g@mail.gmail.com> (raw)
In-Reply-To: <20181021145939.8760-1-sebhtml@videotron.qc.ca>

[ added Andrew ]

Patch here: https://lore.kernel.org/patchwork/patch/1002234/

On Sun, Oct 21, 2018 at 8:00 AM Sebastien Boisvert
<sebhtml@videotron.qc.ca> wrote:
>
> Tracing the event "fs_dax:dax_pmd_insert_mapping" with perf produces this
> warning:
>       [fs_dax:dax_pmd_insert_mapping] unknown op '~'
>
> It is printed in process_op (tools/lib/traceevent/event-parse.c) because '~'
> is parsed as a binary operator.
>
> perf reads the format of fs_dax:dax_pmd_insert_mapping ("print fmt") from
> /sys/kernel/debug/tracing/events/fs_dax/dax_pmd_insert_mapping/format .
>
> The format contains:
>
> ~(((u64) ~(~(((1UL) << 12)-1)))
>          ^
>          \ interpreted as a binary operator by process_op().
>
> This part is generated in the declaration of the event class
> dax_pmd_insert_mapping_class in include/trace/events/fs_dax.h :
>
>                 __print_flags_u64(__entry->pfn_val & PFN_FLAGS_MASK, "|",
>                         PFN_FLAGS_TRACE),
>
> This patch adds a pair of parentheses in the declaration of PFN_FLAGS_MASK to
> make sure that '~' is parsed as a unary operator by perf.
>
> The part of the format that was problematic is now:
>
> ~(((u64) (~(~(((1UL) << 12)-1))))
>
> Now, all the '~' are parsed as unary operators.
>
> Cc: Dan Williams <dan.j.williams@intel.com>


Acked-by: Dan Williams <dan.j.williams@intel.com>


> Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
> Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
> Cc: "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com>
> Cc: Namhyung Kim <namhyung@kernel.org>
> Cc: Ross Zwisler <zwisler@kernel.org>
> Cc: Elenie Godzaridis <arangradient@gmail.com>
> Cc: linux-perf-users@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Sebastien Boisvert <sebhtml@videotron.qc.ca>
> ---
>  include/linux/pfn_t.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/linux/pfn_t.h b/include/linux/pfn_t.h
> index 21713dc14ce2..673546ba7342 100644
> --- a/include/linux/pfn_t.h
> +++ b/include/linux/pfn_t.h
> @@ -10,7 +10,7 @@
>   * PFN_DEV - pfn is not covered by system memmap by default
>   * PFN_MAP - pfn has a dynamic page mapping established by a device driver
>   */
> -#define PFN_FLAGS_MASK (((u64) ~PAGE_MASK) << (BITS_PER_LONG_LONG - PAGE_SHIFT))
> +#define PFN_FLAGS_MASK (((u64) (~PAGE_MASK)) << (BITS_PER_LONG_LONG - PAGE_SHIFT))
>  #define PFN_SG_CHAIN (1ULL << (BITS_PER_LONG_LONG - 1))
>  #define PFN_SG_LAST (1ULL << (BITS_PER_LONG_LONG - 2))
>  #define PFN_DEV (1ULL << (BITS_PER_LONG_LONG - 3))
> --
> 2.17.1
>

  reply	other threads:[~2018-10-22 17:14 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-10-21 14:59 [PATCH] pfn_t: force '~' to be parsed as an unary operator Sebastien Boisvert
2018-10-21 14:59 ` Sebastien Boisvert
2018-10-22 17:13 ` Dan Williams [this message]
2018-10-24 22:43   ` Andrew Morton
     [not found]   ` <FRrzgp7InaOtKFRs0geay1@videotron.ca>
2018-10-24 23:52     ` sebhtml

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=CAPcyv4iJ_bfzOtV_GAQg_tdLLuebE_1Gp420LMG0xbR2ZQdV7g@mail.gmail.com \
    --to=dan.j.williams@intel.com \
    --cc=acme@redhat.com \
    --cc=akpm@linux-foundation.org \
    --cc=arangradient@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-perf-users@vger.kernel.org \
    --cc=namhyung@kernel.org \
    --cc=rostedt@goodmis.org \
    --cc=sebhtml@videotron.qc.ca \
    --cc=tz.stoyanov@gmail.com \
    --cc=zwisler@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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.