linux-kernel - Re: [PATCH] net/smc: Reduce size of smc_wr_tx_tasklet

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <66ce34a0-b79d-4ef0-bdd5-982e139571f1@linux.ibm.com>
Date: Mon, 17 Mar 2025 12:22:46 +0100
From: Wenjia Zhang <wenjia@...ux.ibm.com>
To: I Hsin Cheng <richard120310@...il.com>, alibuda@...ux.alibaba.com
Cc: jaka@...ux.ibm.com, mjambigi@...ux.ibm.com, sidraya@...ux.ibm.com,
        tonylu@...ux.alibaba.com, guwen@...ux.alibaba.com, davem@...emloft.net,
        edumazet@...gle.com, kuba@...nel.org, pabeni@...hat.com,
        horms@...nel.org, linux-rdma@...r.kernel.org,
        linux-s390@...r.kernel.org, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org, skhan@...uxfoundation.org,
        jserv@...s.ncku.edu.tw, linux-kernel-mentees@...ts.linux.dev
Subject: Re: [PATCH] net/smc: Reduce size of smc_wr_tx_tasklet_fn



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