linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Peter Zijlstra <peterz@infradead.org>
To: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
Cc: mhiramat@kernel.org, ananth@linux.ibm.com,
	Christoph Hellwig <hch@lst.de>,
	linux-kernel@vger.kernel.org, mingo@kernel.org,
	rostedt@goodmis.org, x86@kernel.org
Subject: Re: [PATCH] kprobes: Do not increment probe miss count in the fault handler
Date: Tue, 1 Jun 2021 15:20:32 +0200	[thread overview]
Message-ID: <YLY0INyDtfjgVrXv@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20210601120150.672652-1-naveen.n.rao@linux.vnet.ibm.com>

On Tue, Jun 01, 2021 at 05:31:50PM +0530, Naveen N. Rao wrote:
> Kprobes has a counter 'nmissed', that is used to count the number of
> times a probe handler was not called. This generally happens when we hit
> a kprobe while handling another kprobe.
> 
> However, if one of the probe handlers causes a fault, we are currently
> incrementing 'nmissed'. The comment in fault handler indicates that this
> can be used to account faults taken by the probe handlers. But, this has
> never been the intention as is evident from the comment above 'nmissed'
> in 'struct kprobe':
> 
> 	/*count the number of times this probe was temporarily disarmed */
> 	unsigned long nmissed;
> 
> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
> ---
> I'm posting this here so that these can go together, if the patch is ok 
> otherwise.

I had the other two queued in perf/core and was about to push then to
tip, Masami are you good with adding this on top?

  reply	other threads:[~2021-06-01 13:20 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-25  7:25 [PATCH 0/2] kprobes: Remove kprobe::fault_handler Peter Zijlstra
2021-05-25  7:25 ` [PATCH 1/2] " Peter Zijlstra
2021-05-25 14:06   ` Masami Hiramatsu
2021-05-26 10:50   ` Naveen N. Rao
2021-05-26 13:51     ` Masami Hiramatsu
2021-06-01 12:01   ` [PATCH] kprobes: Do not increment probe miss count in the fault handler Naveen N. Rao
2021-06-01 13:20     ` Peter Zijlstra [this message]
2021-06-01 23:48       ` Masami Hiramatsu
2021-06-04 13:38     ` [tip: perf/core] " tip-bot2 for Naveen N. Rao
2021-06-01 14:04   ` [tip: perf/core] kprobes: Remove kprobe::fault_handler tip-bot2 for Peter Zijlstra
2021-05-25  7:25 ` [PATCH 2/2] x86,kprobes: WARN if kprobes tries to handle a fault Peter Zijlstra
2021-05-25 14:21   ` Masami Hiramatsu
2021-06-01 14:04   ` [tip: perf/core] " tip-bot2 for Peter Zijlstra

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=YLY0INyDtfjgVrXv@hirez.programming.kicks-ass.net \
    --to=peterz@infradead.org \
    --cc=ananth@linux.ibm.com \
    --cc=hch@lst.de \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mhiramat@kernel.org \
    --cc=mingo@kernel.org \
    --cc=naveen.n.rao@linux.vnet.ibm.com \
    --cc=rostedt@goodmis.org \
    --cc=x86@kernel.org \
    --subject='Re: [PATCH] kprobes: Do not increment probe miss count in the fault handler' \
    /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

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).