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([2400:79e0:1203:64b0:e174:fd48:2cf7:d01e]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-38e2a20a7b8sm1507273a91.1.2026.07.16.04.53.54 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 16 Jul 2026 04:53:56 -0700 (PDT) Message-ID: <5d0fe256-c1c8-4cf5-a69c-a7e9afa08097@gmail.com> Date: Thu, 16 Jul 2026 19:53:52 +0800 Precedence: bulk X-Mailing-List: cgroups@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] block/cgroup: Drop stale -EBUSY retry from blkg_conf_prep() To: Yang Xiuwei , Tejun Heo , Josef Bacik , Jens Axboe Cc: cgroups@vger.kernel.org, linux-block@vger.kernel.org References: <20260622085623.520209-1-yangxiuwei@kylinos.cn> Content-Language: en-US From: Tang Yizhou In-Reply-To: <20260622085623.520209-1-yangxiuwei@kylinos.cn> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 22/6/26 4:56 pm, Yang Xiuwei wrote: > Since commit 8f4236d9008b ("block: remove QUEUE_FLAG_BYPASS and > ->bypass") nothing in the blkcg blkg lookup/creation path > returns -EBUSY anymore. blkg_conf_prep() nevertheless still > retries at fail_exit with msleep(10) and restart_syscall() > — logic added in 2012 when blk_queue_bypass() could Hi Xiuwei, Thanks for the cleanup. Instead of the vague "logic added in 2012", please mention the commit e56da7e28796 ("blkcg: don't allow or retain configuration of missing devices"). > cause blkg lookup/creation to fail with -EBUSY while the queue was > temporarily bypassed during elevator changes. > > Signed-off-by: Yang Xiuwei > --- > block/blk-cgroup.c | 10 ---------- > 1 file changed, 10 deletions(-) > > diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c > index 3093c1c03902..259f2240e7df 100644 > --- a/block/blk-cgroup.c > +++ b/block/blk-cgroup.c > @@ -919,16 +919,6 @@ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol, > spin_unlock_irq(&q->queue_lock); > fail_exit: > mutex_unlock(&q->blkcg_mutex); > - /* > - * If queue was bypassing, we should retry. Do so after a > - * short msleep(). It isn't strictly necessary but queue > - * can be bypassing for some time and it's always nice to > - * avoid busy looping. > - */ > - if (ret == -EBUSY) { > - msleep(10); Since msleep() is gone, we can also remove #include . With the above addressed, feel free to add: Reviewed-by: Tang Yizhou -- Best Regards, Yi > - ret = restart_syscall(); > - } > return ret; > } > EXPORT_SYMBOL_GPL(blkg_conf_prep);