On 04/12/2016 04:25 PM, Atsushi Kumagai wrote:
> Hello Zhou,
>
>> Hello Atsushi and Minfei,
>>
>> How about this version?
>
> Thanks for making v5 patch.
> I agree with the concept, but I have comments.
>
>>> @@ -10223,6 +10281,20 @@ calculate_cyclic_buffer_size(void) {
>>> * free memory for safety.
>>> */
>>> limit_size = get_free_memory_size() * 0.6;
>>> +
>>> + /*
>>> + * Recalculate the limit_size according to num_threads.
>>> + * And reset num_threads if there is not enough memory.
>>> + */
>>> + if (limit_size < MAP_REGION * info->num_threads) {
>>> + MSG("There isn't enough memory for %d threads.\n", info->num_threads);
>
> You assume only MAP_REGION is the extra memory consumption for multi thread.
> However, there are other stuff allocated in each thread, e.g. BUF_PARALLEL(i)
> and the buffer for compression calculated by calculate_len_buf_out().
>
> Shouldn't we consider them ?
>
Yes.
Previously, I thought we don't need the accurate value.
But now I think it will lead to some failures sometime.
>>> +
>>> + info->num_threads = MIN(info->num_threads % 2, limit_size % MAP_REGION);
>>> + MSG("--num_threads is set to %d.\n", info->num_threads);
>
> What does "info->num_threads % 2" mean ?
>
Something I thought is wrong. I will remove it.
>>> + }
>>> +
>>> + 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?
--
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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