From: Waiman Long <waiman.long@hpe.com>
To: Boqun Feng <boqun.feng@gmail.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>,
Jan Kara <jack@suse.com>, Jeff Layton <jlayton@poochiereds.net>,
"J. Bruce Fields" <bfields@fieldses.org>,
Tejun Heo <tj@kernel.org>,
Christoph Lameter <cl@linux-foundation.org>,
<linux-fsdevel@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Andi Kleen <andi@firstfloor.org>,
Dave Chinner <dchinner@redhat.com>,
Scott J Norton <scott.norton@hpe.com>,
Douglas Hatch <doug.hatch@hpe.com>
Subject: Re: [PATCH v7 1/4] lib/percpu-list: Per-cpu list with associated per-cpu locks
Date: Wed, 13 Apr 2016 13:38:33 -0400 [thread overview]
Message-ID: <570E8419.7090909@hpe.com> (raw)
In-Reply-To: <20160413020929.GA23058@fixme-laptop.cn.ibm.com>
On 04/12/2016 10:09 PM, Boqun Feng wrote:
> Hi Waiman,
>
> On Tue, Apr 12, 2016 at 06:54:43PM -0400, Waiman Long wrote:
> [...]
>> +
>> +/*
>> + * Initialize the per-cpu list head
>> + */
>> +int init_pcpu_list_head(struct pcpu_list_head **ppcpu_head)
>> +{
>> + struct pcpu_list_head *pcpu_head = alloc_percpu(struct pcpu_list_head);
>> + int cpu;
>> +
>> + if (!pcpu_head)
>> + return -ENOMEM;
>> +
>> + for_each_possible_cpu(cpu) {
>> + struct pcpu_list_head *head = per_cpu_ptr(pcpu_head, cpu);
>> +
>> + INIT_LIST_HEAD(&head->list);
>> + head->lock = __SPIN_LOCK_UNLOCKED(&head->lock);
>> + lockdep_set_class(&head->lock,&percpu_list_key);
>> + }
>> +
>> + *ppcpu_head = pcpu_head;
>> + return 0;
>> +}
> The first time I looked at this patch, I had a hard time to figure out
> which "struct pcpu_list_head" pointer is pointing to percpu data(the
> pointer could be the parameter for per/this_cpu_ptr()), and which
> pointer is pointing to actual structure. For example, 'pcpu_head' and
> 'head' above are different types of pointers.
>
> So besides improving my code reading skills, I think the following patch
> helps ;-) Also it can resolve several splats of sparse when running
> 'make C=1 lib/'.
>
> Thoughts?
Yes, I think your patch is helpful. I will include your patch in my
patchset.
Thanks,
Longman
next prev parent reply other threads:[~2016-04-13 17:53 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-12 22:54 [PATCH v7 0/4] vfs: Use per-cpu list for SB's s_inodes list Waiman Long
2016-04-12 22:54 ` [PATCH v7 1/4] lib/percpu-list: Per-cpu list with associated per-cpu locks Waiman Long
2016-04-13 2:09 ` Boqun Feng
2016-04-13 17:38 ` Waiman Long [this message]
2016-04-14 23:33 ` Boqun Feng
2016-04-15 17:14 ` Waiman Long
2016-04-13 15:03 ` Christoph Lameter
2016-04-13 17:47 ` Waiman Long
2016-04-13 18:03 ` Christoph Lameter
2016-04-14 14:10 ` Jan Kara
2016-04-14 18:48 ` Waiman Long
2016-04-12 22:54 ` [PATCH v7 2/4] fsnotify: Simplify inode iteration on umount Waiman Long
2016-04-12 22:54 ` [PATCH v7 3/4] vfs: Remove unnecessary list_for_each_entry_safe() variants Waiman Long
2016-04-12 22:54 ` [PATCH v7 4/4] vfs: Use per-cpu list for superblock's inode list Waiman Long
2016-04-14 14:20 ` Jan Kara
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