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Date:   Thu, 17 Mar 2022 14:24:40 +0100
From:   Jiri Olsa <olsajiri@gmail.com>
To:     Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc:     Jiri Olsa <jolsa@kernel.org>, Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Andrii Nakryiko <andrii@kernel.org>,
        Masami Hiramatsu <mhiramat@kernel.org>, netdev@vger.kernel.org,
        bpf@vger.kernel.org, lkml <linux-kernel@vger.kernel.org>,
        Martin KaFai Lau <kafai@fb.com>,
        Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
        John Fastabend <john.fastabend@gmail.com>,
        KP Singh <kpsingh@chromium.org>,
        Steven Rostedt <rostedt@goodmis.org>
Subject: Re: [PATCHv3 bpf-next 03/13] bpf: Add multi kprobe link
Message-ID: <YjM2mCCSTGWJG1K6@krava>
References: <20220316122419.933957-1-jolsa@kernel.org>
 <20220316122419.933957-4-jolsa@kernel.org>
 <20220316185333.ytyh5irdftjcklk6@ast-mbp.dhcp.thefacebook.com>
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On Wed, Mar 16, 2022 at 11:53:33AM -0700, Alexei Starovoitov wrote:
> On Wed, Mar 16, 2022 at 01:24:09PM +0100, Jiri Olsa wrote:
> > +static int
> > +kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link,
> > +			   struct pt_regs *regs)
> > +{
> > +	int err;
> > +
> > +	if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
> > +		err = 0;
> > +		goto out;
> > +	}
> 
> That's a heavy hammer.
> It's ok-ish for now, but would be good to switch to
> __this_cpu_inc_return(*(prog->active)) at some point.
> The way fentry/fexit progs do.

ok, will check

thanks,
jirka