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Date:   Thu, 29 Dec 2022 23:52:20 +0900
From:   Masami Hiramatsu (Google) <mhiramat@kernel.org>
To:     wuqiang <wuqiang.matt@bytedance.com>
Cc:     davem@davemloft.net, anil.s.keshavamurthy@intel.com,
        naveen.n.rao@linux.ibm.com, rostedt@goodmis.org,
        peterz@infradead.org, akpm@linux-foundation.org,
        sander@svanheule.net, ebiggers@google.com,
        dan.j.williams@intel.com, jpoimboe@kernel.org,
        linux-kernel@vger.kernel.org, lkp@intel.com, mattwu@163.com
Subject: Re: [PATCH v8 0/5] lib,kprobes: kretprobe scalability improvement
Message-Id: <20221229235220.4044edccae7c9d39798af8e9@kernel.org>
In-Reply-To: <20221218050310.1338630-1-wuqiang.matt@bytedance.com>
References: <20221218050310.1338630-1-wuqiang.matt@bytedance.com>
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Hi Matt,

Sorry, I missed to commented v7 patch. Anyway, please read
my comments on previous version.

On Sun, 18 Dec 2022 13:03:05 +0800
wuqiang <wuqiang.matt@bytedance.com> wrote:

> This patch series introduces a scalable and lockless ring-array based
> object pool and replaces the original freelist (a LIFO queue based on
> singly linked list) to improve scalability of kretprobed routines.
> 
> v8:
>   1) objpool: refcount added for objpool lifecycle management

At least this update part looks good to me.
(But I think this may be useful only for kretprobe/rethook
use cases...)

Thank you,

> 
> v7:
>   1) objpool: implementation simplified as Masami advised
>   2) rethook_alloc: error codes returning supported (ERR_PTR)
>   3) MAINTAINERS: support added for objpool files
>   4) synced to latest 6.1 with x86_64/x86/aarch64 verified
> 
> wuqiang (5):
>   lib: objpool added: ring-array based lockless MPMC queue
>   lib: objpool test module added
>   kprobes: kretprobe scalability improvement with objpool
>   kprobes: freelist.h removed
>   MAINTAINERS: objpool added
> 
>  MAINTAINERS              |   7 +
>  include/linux/freelist.h | 129 --------
>  include/linux/kprobes.h  |  11 +-
>  include/linux/objpool.h  | 116 +++++++
>  include/linux/rethook.h  |  16 +-
>  kernel/kprobes.c         |  93 +++---
>  kernel/trace/fprobe.c    |  37 +--
>  kernel/trace/rethook.c   |  91 +++---
>  lib/Kconfig.debug        |  11 +
>  lib/Makefile             |   4 +-
>  lib/objpool.c            | 372 +++++++++++++++++++++
>  lib/test_objpool.c       | 682 +++++++++++++++++++++++++++++++++++++++
>  12 files changed, 1292 insertions(+), 277 deletions(-)
>  delete mode 100644 include/linux/freelist.h
>  create mode 100644 include/linux/objpool.h
>  create mode 100644 lib/objpool.c
>  create mode 100644 lib/test_objpool.c
> 
> -- 
> 2.34.1
> 


-- 
Masami Hiramatsu (Google) <mhiramat@kernel.org>