From: Namhyung Kim <namhyung.kim@lge.com>
To: shaohua.li@intel.com
Cc: linux-kernel@vger.kernel.org, axboe@kernel.dk, vgoyal@redhat.com,
jmoyer@redhat.com
Subject: Re: [RFC 1/3]block: seperate CFQ io context management code
Date: Wed, 04 Jan 2012 17:19:51 +0900 [thread overview]
Message-ID: <4F040BA7.9070203@lge.com> (raw)
In-Reply-To: <20120104065454.001785808@sli10-conroe.sh.intel.com>
Hi,
Two of nitpicks below ..
2012-01-04 3:53 PM, Shaohua Li Wrote:
> CFQ's io context management creates a per-device io context for each task.
> It's quite generic. Separate it from CFQ, and use it for fiops I/O scheduler.
>
> Signed-off-by: Shaohua Li<shaohua.li@intel.com>
> ---
[snip]
> +int ioc_builder_init(struct ioc_builder *builder)
> +{
> + if (!builder->alloc_ioc || !builder->free_ioc)
> + return -ENOMEM;
> +
> + builder->ioc_count = alloc_percpu(unsigned long);
> + if (!builder->ioc_count)
> + return -ENOMEM;
> +
> + builder->ioc_gone = NULL;
> + spin_lock_init(&builder->ioc_gone_lock);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(ioc_builder_init);
> +
> +void io_context_builder_exit(struct ioc_builder *builder)
It'd be better using 'ioc_builder_exit' as a name for consistency, IMHO.
> +{
> + DECLARE_COMPLETION_ONSTACK(all_gone);
> +
> + builder->ioc_gone =&all_gone;
> + /* ioc_gone's update must be visible before reading ioc_count */
> + smp_wmb();
> +
> + /*
> + * this also protects us from entering cfq_slab_kill() with
> + * pending RCU callbacks
> + */
> + if (elv_ioc_count_read(*builder->ioc_count))
> + wait_for_completion(&all_gone);
> +
> + free_percpu(builder->ioc_count);
> +}
> +EXPORT_SYMBOL(io_context_builder_exit);
[snip]
> +static void queue_data_cic_free_rcu(struct rcu_head *head)
> +{
> + struct dev_io_context *cic;
> + struct ioc_builder *builder;
> +
> + cic = container_of(head, struct dev_io_context, rcu_head);
> + builder = cic->builder;
> +
> + builder->free_ioc(builder, cic);
> + elv_ioc_count_dec(*builder->ioc_count);
> +
> + if (builder->ioc_gone) {
> + /*
> + * CFQ scheduler is exiting, grab exit lock and check
s/CFQ/IO/ ?
Thanks.
Namhyung Kim
next prev parent reply other threads:[~2012-01-04 8:30 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-04 6:53 [RFC 0/3]block: An IOPS based ioscheduler Shaohua Li
2012-01-04 6:53 ` [RFC 1/3]block: seperate CFQ io context management code Shaohua Li
2012-01-04 8:19 ` Namhyung Kim [this message]
2012-01-04 6:53 ` [RFC 2/3]block: FIOPS ioscheduler core Shaohua Li
2012-01-06 6:05 ` Namjae Jeon
2012-01-07 1:06 ` Zhu Yanhai
2012-01-04 6:53 ` [RFC 3/3]block: fiops read/write request scale Shaohua Li
2012-01-04 7:19 ` [RFC 0/3]block: An IOPS based ioscheduler Dave Chinner
2012-01-05 6:50 ` Shaohua Li
2012-01-06 5:12 ` Shaohua Li
2012-01-06 9:10 ` Namhyung Kim
2012-01-06 14:37 ` Jan Kara
2012-01-09 1:26 ` Shaohua Li
2012-01-15 22:32 ` Vivek Goyal
2012-01-08 22:16 ` Dave Chinner
2012-01-09 1:09 ` Shaohua Li
2012-01-15 22:45 ` Vivek Goyal
2012-01-16 4:36 ` Shaohua Li
2012-01-16 7:11 ` Vivek Goyal
2012-01-16 7:55 ` Shaohua Li
2012-01-16 8:29 ` Vivek Goyal
2012-01-17 1:06 ` Shaohua Li
2012-01-17 9:02 ` Vivek Goyal
2012-01-18 1:20 ` Shaohua Li
2012-01-18 13:04 ` Vivek Goyal
2012-01-19 1:21 ` Shaohua Li
2012-01-15 22:28 ` Vivek Goyal
2012-01-06 9:41 ` Zhu Yanhai
2012-01-15 22:24 ` Vivek Goyal
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