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Subject: Re: [PATCH vmalloc] reduce purge_lock range and hold time of
To: Christoph Hellwig <hch@infradead.org>
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 <20161015165521.GB31568@infradead.org>
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From: zhouxianrong <zhouxianrong@huawei.com>
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Date: Tue, 18 Oct 2016 10:55:26 +0800
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hey Hellwig:
	cond_resched_lock is a good choice. i mixed the cond_resched_lock and batch to balance of
realtime and performance and resubmit this patch.

On 2016/10/16 0:55, Christoph Hellwig wrote:
> On Sat, Oct 15, 2016 at 10:12:48PM +0800, zhouxianrong@huawei.com wrote:
>> From: z00281421 <z00281421@notesmail.huawei.com>
>>
>> i think no need to place __free_vmap_area loop in purge_lock;
>> _free_vmap_area could be non-atomic operations with flushing tlb
>> but must be done after flush tlb. and the whole__free_vmap_area loops
>> also could be non-atomic operations. if so we could improve realtime
>> because the loop times sometimes is larg and spend a few time.
>
> Right, see the previous patch in reply to Joel that drops purge_lock
> entirely.
>
> Instead of your open coded batch counter you probably want to add
> a cond_resched_lock after the call to __free_vmap_area.
>
> .
>