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From:   Thomas Gleixner <tglx@linutronix.de>
To:     Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc:     LKML <linux-kernel@vger.kernel.org>,
        David Miller <davem@davemloft.net>, bpf@vger.kernel.org,
        netdev@vger.kernel.org, Alexei Starovoitov <ast@kernel.org>,
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        Sebastian Sewior <bigeasy@linutronix.de>,
        Peter Zijlstra <peterz@infradead.org>,
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        Juri Lelli <juri.lelli@redhat.com>,
        Ingo Molnar <mingo@kernel.org>,
        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
        Vinicius Costa Gomes <vinicius.gomes@intel.com>,
        Jakub Kicinski <kuba@kernel.org>
Subject: Re: [patch V3 06/22] bpf/trace: Remove redundant preempt_disable from trace_call_bpf()
In-Reply-To: <20200225003351.vvsrgyta47ciqhvo@ast-mbp>
References: <20200224140131.461979697@linutronix.de> <20200224145643.059995527@linutronix.de> <20200224194017.rtwjcgjxnmltisfe@ast-mbp> <875zfvk983.fsf@nanos.tec.linutronix.de> <20200225003351.vvsrgyta47ciqhvo@ast-mbp>
Date:   Tue, 25 Feb 2020 13:36:15 +0100
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Alexei Starovoitov <alexei.starovoitov@gmail.com> writes:
> On Mon, Feb 24, 2020 at 09:42:52PM +0100, Thomas Gleixner wrote:
>> > But looking at your patch cant_sleep() seems unnecessary strong.
>> > Should it be cant_migrate() instead?
>> 
>> Yes, if we go with the migrate_disable(). OTOH, having a
>> preempt_disable() in that uprobe callsite should work as well, then we
>> can keep the cant_sleep() check which covers all other callsites
>> properly. No strong opinion though.
>
> ok. I went with preempt_disable() for uprobes. It's simpler.
> And pushed the whole set to bpf-next.
> In few days we'll send it to Dave for net-next and on the way
> to Linus's next release. imo it's a big milestone.
> Thank you for the hard work to make it happen.

Thank you for guidance and review!

      tglx