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Mon, 17 Mar 2025 11:22:51 GMT Received: from smtpav03.wdc07v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 3321C5805C; Mon, 17 Mar 2025 11:22:51 +0000 (GMT) Received: from smtpav03.wdc07v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id BA2A358054; Mon, 17 Mar 2025 11:22:47 +0000 (GMT) Received: from [9.171.94.58] (unknown [9.171.94.58]) by smtpav03.wdc07v.mail.ibm.com (Postfix) with ESMTP; Mon, 17 Mar 2025 11:22:47 +0000 (GMT) Message-ID: <66ce34a0-b79d-4ef0-bdd5-982e139571f1@linux.ibm.com> Date: Mon, 17 Mar 2025 12:22:46 +0100 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] net/smc: Reduce size of smc_wr_tx_tasklet_fn To: I Hsin Cheng , alibuda@linux.alibaba.com Cc: jaka@linux.ibm.com, mjambigi@linux.ibm.com, sidraya@linux.ibm.com, tonylu@linux.alibaba.com, guwen@linux.alibaba.com, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, horms@kernel.org, linux-rdma@vger.kernel.org, linux-s390@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, skhan@linuxfoundation.org, jserv@ccns.ncku.edu.tw, linux-kernel-mentees@lists.linux.dev References: <20250315062516.788528-1-richard120310@gmail.com> Content-Language: en-US From: Wenjia Zhang In-Reply-To: <20250315062516.788528-1-richard120310@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-GUID: YrURz_ERbaNDYvI-YlvHKtnMUZ56YnS1 X-Proofpoint-ORIG-GUID: dmmfzEmZNCCI5O1ySa_aDr9ZzpvUdf2i X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1093,Hydra:6.0.680,FMLib:17.12.68.34 definitions=2025-03-17_04,2025-03-17_01,2024-11-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 clxscore=1011 spamscore=0 adultscore=0 phishscore=0 bulkscore=0 lowpriorityscore=0 priorityscore=1501 suspectscore=0 mlxscore=0 impostorscore=0 malwarescore=0 mlxlogscore=999 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2502280000 definitions=main-2503170080 On 15.03.25 07:25, I Hsin Cheng wrote: > The variable "polled" in smc_wr_tx_tasklet_fn is a counter to determine > whether the loop has been executed for the first time. Refactor the type > of "polled" from "int" to "bool" can reduce the size of generated code > size by 12 bytes shown with the test below > > $ ./scripts/bloat-o-meter vmlinux_old vmlinux_new > add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-12 (-12) > Function old new delta > smc_wr_tx_tasklet_fn 1076 1064 -12 > Total: Before=24795091, After=24795079, chg -0.00% > > In some configuration, the compiler will complain this function for > exceeding 1024 bytes for function stack, this change can at least reduce > the size by 12 bytes within manner. > The code itself looks good. However, I’m curious about the specific situation where the compiler complained. Also, compared to exceeding the function stack limit by 1024 bytes, I don’t see how saving 12 bytes would bring any significant benefit. Thanks, Wenjia