Re: [dpdk-dev] [PATCH v2] support free hugepages

[Linhaifeng <haifeng.lin@huawei.com>]

On 2014/10/29 14:14, Qiu, Michael wrote:
> 在 10/29/2014 1:49 PM, linhaifeng 写道:
>> rte_eal_hugepage_free() is used for unlink all hugepages.If you want to
>> free all hugepages you must make sure that you have stop to use it,and you
>> must call this function before exit process.
>>
>> Signed-off-by: linhaifeng <haifeng.lin@huawei.com>
>> ---
>>  .../lib/librte_eal/common/include/rte_memory.h     | 11 ++++++++
>>  .../lib/librte_eal/linuxapp/eal/eal_memory.c       | 31 ++++++++++++++++++++++
>>  2 files changed, 42 insertions(+)
>>
>> diff --git a/dpdk/dpdk-1.7.0/lib/librte_eal/common/include/rte_memory.h b/dpdk/dpdk-1.7.0/lib/librte_eal/common/include/rte_memory.h
>> index 4cf8ea9..f6ad95f 100644
>> --- a/dpdk/dpdk-1.7.0/lib/librte_eal/common/include/rte_memory.h
>> +++ b/dpdk/dpdk-1.7.0/lib/librte_eal/common/include/rte_memory.h
>> @@ -172,6 +172,17 @@ unsigned rte_memory_get_nchannel(void);
>>   */
>>  unsigned rte_memory_get_nrank(void);
>>  
>> +/**
>> + * Unlink all hugepages which created by dpdk.
>> + *
>> + * @param void
>> + *
>> + * @return
>> + *       0: successfully
>> + *       negative: error
>> + */
>> +int rte_eal_hugepage_free(void);
>> +
>>  #ifdef RTE_LIBRTE_XEN_DOM0
>>  /**
>>   * Return the physical address of elt, which is an element of the pool mp.
>> diff --git a/dpdk/dpdk-1.7.0/lib/librte_eal/linuxapp/eal/eal_memory.c b/dpdk/dpdk-1.7.0/lib/librte_eal/linuxapp/eal/eal_memory.c
>> index f2454f4..109207c 100644
>> --- a/dpdk/dpdk-1.7.0/lib/librte_eal/linuxapp/eal/eal_memory.c
>> +++ b/dpdk/dpdk-1.7.0/lib/librte_eal/linuxapp/eal/eal_memory.c
>> @@ -98,6 +98,13 @@
>>  #include "eal_filesystem.h"
>>  #include "eal_hugepages.h"
>>  
>> +struct hugepage_table {
>> +	struct hugepage_file *hugepg_tbl;
>> +	unsigned nr_hugefiles;
>> +};
>> +
>> +static struct hugepage_table g_hugepage_table;
>> +
>>  /**
>>   * @file
>>   * Huge page mapping under linux
>> @@ -1202,6 +1209,7 @@ rte_eal_hugepage_init(void)
>>  						(unsigned)
>>  							(used_hp[i].hugepage_sz / 0x100000),
>>  						j);
>> +				g_hugepage_table.nr_hugefiles += used_hp[i].num_pages[j];
>>  			}
>>  		}
>>  	}
>> @@ -1237,6 +1245,8 @@ rte_eal_hugepage_init(void)
>>  		goto fail;
>>  	}
>>  
>> +	g_hugepage_table.hugepg_tbl = hugepage;
>> +
>>  	/* free the temporary hugepage table */
>>  	free(tmp_hp);
>>  	tmp_hp = NULL;
>> @@ -1487,6 +1497,27 @@ error:
>>  	return -1;
>>  }
>>  
>> +int
>> +rte_eal_hugepage_free(void)
>> +{
>> +	struct hugepage_file *hugepg_tbl = g_hugepage_table.hugepg_tbl;
>> +	unsigned i;
>> +	unsigned nr_hugefiles = g_hugepage_table.nr_hugefiles;
>> +	int ret = 0;
>> +
>> +	for (i = 0; i < nr_hugefiles; i++) {
>> +		ret = unlink(hugepg_tbl[i].filepath);
>> +		if (ret != 0) {
>> +			RTE_LOG(ERR, EAL, "Failed to unlink %s", hugepg_tbl[i].filepath);
>> +			return ret;
>> +		}
>> +		hugepg_tbl[i].orig_va = NULL;
> 
> BTW, is it better to first set hugepg_tbl[i].orig_vato NULL, then unlink
> filepath?
> It may be not a good idea to first remove then set to NULL.
> 
> Thanks,
> Michael
> 

If first set hugepg_tbl[i].orig_va to NULL,then failed to unlink you have to restore hugepg_tbl[i].orig_va.
So I first to unlink for less codes.

>> +	}
>> +
>> +	RTE_LOG(INFO, EAL, "unlink %u hugepage files\n", nr_hugefiles);
>> +	return ret;
>> +}
>> +
>>  static int
>>  rte_eal_memdevice_init(void)
>>  {
> 
> 
> .
> 

-- 
Regards,
Haifeng