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Date:   Fri, 4 Nov 2022 00:46:55 +0800
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Subject: Re: [PATCH v4] kprobes,lib: kretprobe scalability improvement
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To:     Andrew Morton <akpm@linux-foundation.org>
Cc:     mhiramat@kernel.org, davem@davemloft.net,
        anil.s.keshavamurthy@intel.com, naveen.n.rao@linux.ibm.com,
        rostedt@goodmis.org, peterz@infradead.org, sander@svanheule.net,
        ebiggers@google.com, dan.j.williams@intel.com, jpoimboe@kernel.org,
        linux-kernel@vger.kernel.org, mattwu@163.com,
        kernel test robot <lkp@intel.com>
References: <20221101014346.150812-1-wuqiang.matt@bytedance.com>
 <20221102023012.6362-1-wuqiang.matt@bytedance.com>
 <20221102143312.a1b09fe962e8e1057fd4a872@linux-foundation.org>
From:   wuqiang <wuqiang.matt@bytedance.com>
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On 2022/11/3 05:33, Andrew Morton wrote:
> On Wed,  2 Nov 2022 10:30:12 +0800 wuqiang <wuqiang.matt@bytedance.com> wrote:
> 
>> Tests of
>> kretprobe throughput show the biggest ratio as 333.9x of the original
>> freelist.
> 
> Seriously.
> 
> I'll add this for some runtime testing.

Thanks.

> 
> Are you able to identify other parts of the kernel which could use
> (and benefit from) the new objpool?

The scalability issue is caused by freelist. Currently kretprobe and rethook 
are the only use cases.

I'm working on the evaluation of bpf percpu-freelist, which scales well but 
uses raw_spinlock and needs local irq disabled.