Message-id: <54E4641A.9050709@partner.samsung.com>
Date: Wed, 18 Feb 2015 13:06:18 +0300
From: Stefan Strogin <s.strogin@partner.samsung.com>
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To: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        Andrew Morton <akpm@linux-foundation.org>,
        Marek Szyprowski <m.szyprowski@samsung.com>,
        Michal Nazarewicz <mina86@mina86.com>, aneesh.kumar@linux.vnet.ibm.com,
        Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
        Dmitry Safonov <d.safonov@partner.samsung.com>,
        Pintu Kumar <pintu.k@samsung.com>,
        Weijie Yang <weijie.yang@samsung.com>,
        Laura Abbott <lauraa@codeaurora.org>,
        SeongJae Park <sj38.park@gmail.com>, Hui Zhu <zhuhui@xiaomi.com>,
        Minchan Kim <minchan@kernel.org>, Dyasly Sergey <s.dyasly@samsung.com>,
        Vyacheslav Tyrtov <v.tyrtov@samsung.com>, gregory.0xf0@gmail.com,
        sasha.levin@oracle.com, gioh.kim@lge.com, pavel@ucw.cz,
        stefan.strogin@gmail.com
Subject: Re: [PATCH 1/4] mm: cma: add currently allocated CMA buffers list to
 debugfs
References: <cover.1423777850.git.s.strogin@partner.samsung.com>
 <c4f408198ec7ea7656ae29220c1f96081bd2ade5.1423777850.git.s.strogin@partner.samsung.com>
 <20150213031613.GJ6592@js1304-P5Q-DELUXE>
In-reply-to: <20150213031613.GJ6592@js1304-P5Q-DELUXE>
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Hello

On 13/02/15 06:16, Joonsoo Kim wrote:
> On Fri, Feb 13, 2015 at 01:15:41AM +0300, Stefan Strogin wrote:
>>  static int cma_debugfs_get(void *data, u64 *val)
>>  {
>>  	unsigned long *p = data;
>> @@ -125,6 +221,52 @@ static int cma_alloc_write(void *data, u64 val)
>>  
>>  DEFINE_SIMPLE_ATTRIBUTE(cma_alloc_fops, NULL, cma_alloc_write, "%llu\n");
>>  
>> +static int cma_buffers_read(struct file *file, char __user *userbuf,
>> +				size_t count, loff_t *ppos)
>> +{
>> +	struct cma *cma = file->private_data;
>> +	struct cma_buffer *cmabuf;
>> +	struct stack_trace trace;
>> +	char *buf;
>> +	int ret, n = 0;
>> +
>> +	if (*ppos < 0 || !count)
>> +		return -EINVAL;
>> +
>> +	buf = kmalloc(count, GFP_KERNEL);
>> +	if (!buf)
>> +		return -ENOMEM;
> 
> Is count limited within proper size boundary for kmalloc()?
> If it can exceed page size, using vmalloc() is better than this.
> 
> Thanks.
> 

You are right. On my systems it is always much bigger than page size.
Thanks.
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