On 04/13/2016 04:07 PM, Atsushi Kumagai wrote:
>>>>> + }
>>>>> +
>>>>> + limit_size = limit_size - MAP_REGION * info->num_threads;
>>>>> +
>>>
>>> This patch prioritizes the memory for multi thread since it is reserved first,
>>> but I think enough cyclic buffer should be reserved first because it's for more
>>> fundamental feature than multi-threading.
>>>
>>
>> I'm not sure what is the proper value of cyclic buffer size.
>> Should we leave 4MB for it?
>> Or calculate according to the bitmap_size?
>
> In commit:0b7328280, we decided 4MB is enough, please leave it.
>
> BTW, mmap() in 2nd kernel doesn't consume MAP_REGION(4MB) of physical memory
> since the target region is mapped directly to the old memory(/proc/vmcore).
> If 4MB region is mapped, 8KB of page table for the region will be created,
> *this* is the memory footprint of mmap().
>
> OTOH, mmap() in 1st kernel will consume physical memory to copy file data
> from disk to memory by page fault. However, 1st kernel environment must have
> enough free memory, we don't need to worry too much about it.
>
> So now I don't think MAP_REGION should be considered as memory footprint.
> How about you ?
>
Ah, I didn't know that.
And I was strange why the memory each threads costs is far less than 4MB.
Thanks a lot for telling me that!
--
Thanks
Zhou
>
> Thanks,
> Atsushi Kumagai
>
>> --
>> Thanks
>> Zhou
>>>
>>> Thanks,
>>> Atsushi Kumagai
>>>
>>>>> /* Try to keep both 1st and 2nd bitmap at the same time. */
>>>>> bitmap_size = info->max_mapnr * 2 / BITPERBYTE;
>>>>>
>>>>> diff --git a/makedumpfile.h b/makedumpfile.h
>>>>> index e0b5bbf..4b315c0 100644
>>>>> --- a/makedumpfile.h
>>>>> +++ b/makedumpfile.h
>>>>> @@ -44,6 +44,7 @@
>>>>> #include "print_info.h"
>>>>> #include "sadump_mod.h"
>>>>> #include <pthread.h>
>>>>> +#include <semaphore.h>
>>>>>
>>>>> /*
>>>>> * Result of command
>>>>> @@ -977,7 +978,7 @@ typedef unsigned long long int ulonglong;
>>>>> #define PAGE_DATA_NUM (50)
>>>>> #define WAIT_TIME (60 * 10)
>>>>> #define PTHREAD_FAIL ((void *)-2)
>>>>> -#define NUM_BUFFERS (50)
>>>>> +#define NUM_BUFFERS (20)
>>>>>
>>>>> struct mmap_cache {
>>>>> char *mmap_buf;
>>>>> @@ -985,28 +986,33 @@ struct mmap_cache {
>>>>> off_t mmap_end_offset;
>>>>> };
>>>>>
>>>>> +enum {
>>>>> + FLAG_UNUSED,
>>>>> + FLAG_READY,
>>>>> + FLAG_FILLING
>>>>> +};
>>>>> +struct page_flag {
>>>>> + mdf_pfn_t pfn;
>>>>> + char zero;
>>>>> + char ready;
>>>>> + short index;
>>>>> + struct page_flag *next;
>>>>> +};
>>>>> +
>>>>> struct page_data
>>>>> {
>>>>> - mdf_pfn_t pfn;
>>>>> - int dumpable;
>>>>> - int zero;
>>>>> - unsigned int flags;
>>>>> long size;
>>>>> unsigned char *buf;
>>>>> - pthread_mutex_t mutex;
>>>>> - /*
>>>>> - * whether the page_data is ready to be consumed
>>>>> - */
>>>>> - int ready;
>>>>> + int flags;
>>>>> + int used;
>>>>> };
>>>>>
>>>>> struct thread_args {
>>>>> int thread_num;
>>>>> unsigned long len_buf_out;
>>>>> - mdf_pfn_t start_pfn, end_pfn;
>>>>> - int page_data_num;
>>>>> struct cycle *cycle;
>>>>> struct page_data *page_data_buf;
>>>>> + struct page_flag *page_flag_buf;
>>>>> };
>>>>>
>>>>> /*
>>>>> @@ -1295,11 +1301,12 @@ struct DumpInfo {
>>>>> pthread_t **threads;
>>>>> struct thread_args *kdump_thread_args;
>>>>> struct page_data *page_data_buf;
>>>>> + struct page_flag **page_flag_buf;
>>>>> + sem_t page_flag_buf_sem;
>>>>> pthread_rwlock_t usemmap_rwlock;
>>>>> mdf_pfn_t current_pfn;
>>>>> pthread_mutex_t current_pfn_mutex;
>>>>> - mdf_pfn_t consumed_pfn;
>>>>> - pthread_mutex_t consumed_pfn_mutex;
>>>>> + pthread_mutex_t page_data_mutex;
>>>>> pthread_mutex_t filter_mutex;
>>>>> };
>>>>> extern struct DumpInfo *info;
>>>>>
>>>>
>>>>
>>>>
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>>
>>
