RE: [PATCH v2 2/2] fs: proc: Include cma info in proc/meminfo

[PINTU KUMAR]

Hi,

----- Original Message -----
> From: Gioh Kim <gioh.kim@xxxxxxx>
> To: Pintu Kumar <pintu.k@xxxxxxxxxxx>; akpm@xxxxxxxxxxxxxxxxxxxx;
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> Cc: pintu_agarwal@xxxxxxxxx; cpgs@xxxxxxxxxxx; vishnu.ps@xxxxxxxxxxx;
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> Sent: Thursday, 23 October 2014 5:49 AM
> Subject: Re: [PATCH v2 2/2] fs: proc: Include cma info in proc/meminfo
> 
> 
> 
> 2014-10-22 오후 11:06, Pintu Kumar 쓴 글:
>> This patch include CMA info (CMATotal, CMAFree) in /proc/meminfo.
>> Currently, in a CMA enabled system, if somebody wants to know the
>> total CMA size declared, there is no way to tell, other than the dmesg
>> or /var/log/messages logs.
>> With this patch we are showing the CMA info as part of meminfo, so that
>> it can be determined at any point of time.
>> This will be populated only when CMA is enabled.
>> 
>> Below is the sample output from a ARM based device with RAM:512MB and 
> CMA:16MB.
>> 
>> MemTotal:        471172 kB
>> MemFree:          111712 kB
>> MemAvailable:    271172 kB
>> .
>> .
>> .
>> CmaTotal:          16384 kB
>> CmaFree:            6144 kB
>> 
>> This patch also fix below checkpatch errors that were found during these 
> changes.
> 
> Why don't you split patch for it?
> I think there's a rule not to mix separate patchs.
> 

Last time when we submitted separate patches for checkpatch errors, it was
suggested to 
Include these kinds of fixes along with some meaningful patches together.
So, we included it in same patch.

>> 
>> ERROR: space required after that ',' (ctx:ExV)
>> 199: FILE: fs/proc/meminfo.c:199:
>> +      ,atomic_long_read(&num_poisoned_pages) << (PAGE_SHIFT - 
> 10)
>>           ^
>> 
>> ERROR: space required after that ',' (ctx:ExV)
>> 202: FILE: fs/proc/meminfo.c:202:
>> +      ,K(global_page_state(NR_ANON_TRANSPARENT_HUGEPAGES) *
>>           ^
>> 
>> ERROR: space required after that ',' (ctx:ExV)
>> 206: FILE: fs/proc/meminfo.c:206:
>> +      ,K(totalcma_pages)
>>           ^
>> 
>> total: 3 errors, 0 warnings, 2 checks, 236 lines checked
>> 
>> Signed-off-by: Pintu Kumar <pintu.k@xxxxxxxxxxx>
>> Signed-off-by: Vishnu Pratap Singh <vishnu.ps@xxxxxxxxxxx>
>> ---
>>   fs/proc/meminfo.c |  15 +++++++++++++--
>>   1 file changed, 13 insertions(+), 2 deletions(-)
>> 
>> diff --git a/fs/proc/meminfo.c b/fs/proc/meminfo.c
>> index aa1eee0..d3ebf2e 100644
>> --- a/fs/proc/meminfo.c
>> +++ b/fs/proc/meminfo.c
>> @@ -12,6 +12,9 @@
>>   #include <linux/vmstat.h>
>>   #include <linux/atomic.h>
>>   #include <linux/vmalloc.h>
>> +#ifdef CONFIG_CMA
>> +#include <linux/cma.h>
>> +#endif
>>   #include <asm/page.h>
>>   #include <asm/pgtable.h>
>>   #include "internal.h"
>> @@ -138,6 +141,10 @@ static int meminfo_proc_show(struct seq_file *m,
void 
> *v)
>>   #ifdef CONFIG_TRANSPARENT_HUGEPAGE
>>           "AnonHugePages:  %8lu kB\n"
>>   #endif
>> +#ifdef CONFIG_CMA
>> +        "CmaTotal:      %8lu kB\n"
>> +        "CmaFree:        %8lu kB\n"
>> +#endif
>>           ,
>>           K(i.totalram),
>>           K(i.freeram),
>> @@ -187,12 +194,16 @@ static int meminfo_proc_show(struct seq_file *m,
void 
> *v)
>>           vmi.used >> 10,
>>           vmi.largest_chunk >> 10
>>   #ifdef CONFIG_MEMORY_FAILURE
>> -        ,atomic_long_read(&num_poisoned_pages) << (PAGE_SHIFT - 
> 10)
>> +        , atomic_long_read(&num_poisoned_pages) << (PAGE_SHIFT - 
> 10)
>>   #endif
>>   #ifdef CONFIG_TRANSPARENT_HUGEPAGE
>> -        ,K(global_page_state(NR_ANON_TRANSPARENT_HUGEPAGES) *
>> +        , K(global_page_state(NR_ANON_TRANSPARENT_HUGEPAGES) *
>>             HPAGE_PMD_NR)
>>   #endif
>> +#ifdef CONFIG_CMA
>> +        , K(totalcma_pages)
>> +        , K(global_page_state(NR_FREE_CMA_PAGES))
>> +#endif
>>           );
> 
> Just for sure, are zoneinfo and pagetypeinfo not suitable?
> 

I think zoneinfo shows only current free cma pages.
Same is the case with vmstat.
# cat /proc/zoneinfo | grep cma
    nr_free_cma  2560
# cat /proc/vmstat | grep cma
nr_free_cma 2560

> I don't know HOTPLUG feature so I'm just asking for sure.
> Does HOTPLUG not need printing message like this?
> 

Sorry, I am also not sure what hotplug feature you are referring to.

> Thanks a lot.
> 
> 
>>   
>>       hugetlb_report_meminfo(m);
>> 
> 
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