Hello Minfei,
Since I can't produce the bug, I reviewed the patch and wrote an increment patch.
Though there are some bugs in the increment patch,
I wonder if the previous bug still exists with this patch.
Could you help me confirm it?
And I have another question.
Did it only occur in patch v4?
The previous patches almost have the same logic.
--
Thanks
Zhou
On 03/15/2016 02:34 PM, Minfei Huang wrote:
> Hi, Zhou.
>
> I have applied this patch base on 1.5.9. There are several testcases I
> have tested.
>
> - makedumpfile --num-threads 64 -d 31
> real 0m0.010s
> user 0m0.002s
> sys 0m0.009s
>
> - makedumpfile --num-threads 31 -d 31
> real 2m40.915s
> user 10m50.900s
> sys 23m9.664s
>
> makedumpfile --num-threads 30 -d 31
> real 0m0.006s
> user 0m0.002s
> sys 0m0.004s
>
> makedumpfile --num-threads 32 -d 31
> real 0m0.007s
> user 0m0.002s
> sys 0m0.005s
>
> - makedumpfile --num-threads 8 -d 31
> real 2m32.692s
> user 7m4.630s
> sys 2m0.369s
>
> - makedumpfile --num-threads 1 -d 31
> real 4m42.423s
> user 7m27.153s
> sys 0m22.490s
>
> - makedumpfile.orig -d 31
> real 4m1.297s
> user 3m39.696s
> sys 0m15.200s
>
> This patch has a huge increment to the filter performance under 31. But
> it is not stable, since makedumpfile fails to dump vmcore intermittently.
> You can find the above test result, makedumpfile fails to dump vmcore
> with option --num-threads 64, also it may occur with option
> --number-threads 8.
>
> Thanks
> Minfei
>
> On 03/09/16 at 08:27am, Zhou Wenjian wrote:
>> v4:
>> 1. fix a bug caused by the logic
>> v3:
>> 1. remove some unused variables
>> 2. fix a bug caused by the wrong logic
>> 3. fix a bug caused by optimising
>> 4. improve more performance by using Minoru Usui's code
>>
>> multi-threads implementation will introduce extra cost when handling
>> each page. The origin implementation will also do the extra work for
>> filtered pages. So there is a big performance degradation in
>> --num-threads -d 31.
>> The new implementation won't do the extra work for filtered pages any
>> more. So the performance of -d 31 is close to that of serial processing.
>>
>> The new implementation is just like the following:
>> * The basic idea is producer producing page and consumer writing page.
>> * Each producer have a page_flag_buf list which is used for storing
>> page's description.
>> * The size of page_flag_buf is little so it won't take too much memory.
>> * And all producers will share a page_data_buf array which is
>> used for storing page's compressed data.
>> * The main thread is the consumer. It will find the next pfn and write
>> it into file.
>> * The next pfn is smallest pfn in all page_flag_buf.
>>
>> Signed-off-by: Minoru Usui <min-usui at ti.jp.nec.com>
>> Signed-off-by: Zhou Wenjian <zhouwj-fnst at cn.fujitsu.com>
>> ---
>> makedumpfile.c | 298 +++++++++++++++++++++++++++++++++++----------------------
>> makedumpfile.h | 35 ++++---
>> 2 files changed, 202 insertions(+), 131 deletions(-)
>>
>> diff --git a/makedumpfile.c b/makedumpfile.c
>> index fa0b779..2b0864a 100644
>> --- a/makedumpfile.c
>> +++ b/makedumpfile.c
>> @@ -3483,7 +3483,8 @@ initial_for_parallel()
>> unsigned long page_data_buf_size;
>> unsigned long limit_size;
>> int page_data_num;
>> - int i;
>> + struct page_flag *current;
>> + int i, j;
>>
>> len_buf_out = calculate_len_buf_out(info->page_size);
>>
>> @@ -3560,10 +3561,16 @@ initial_for_parallel()
>>
>> limit_size = (get_free_memory_size()
>> - MAP_REGION * info->num_threads) * 0.6;
>> + if (limit_size < 0) {
>> + MSG("Free memory is not enough for multi-threads\n");
>> + return FALSE;
>> + }
>>
>> page_data_num = limit_size / page_data_buf_size;
>> + info->num_buffers = 3 * info->num_threads;
>>
>> - info->num_buffers = MIN(NUM_BUFFERS, page_data_num);
>> + info->num_buffers = MAX(info->num_buffers, NUM_BUFFERS);
>> + info->num_buffers = MIN(info->num_buffers, page_data_num);
>>
>> DEBUG_MSG("Number of struct page_data for produce/consume: %d\n",
>> info->num_buffers);
>> @@ -3588,6 +3595,36 @@ initial_for_parallel()
>> }
>>
>> /*
>> + * initial page_flag for each thread
>> + */
>> + if ((info->page_flag_buf = malloc(sizeof(void *) * info->num_threads))
>> + == NULL) {
>> + MSG("Can't allocate memory for page_flag_buf. %s\n",
>> + strerror(errno));
>> + return FALSE;
>> + }
>> + memset(info->page_flag_buf, 0, sizeof(void *) * info->num_threads);
>> +
>> + for (i = 0; i < info->num_threads; i++) {
>> + if ((info->page_flag_buf[i] = calloc(1, sizeof(struct page_flag))) == NULL) {
>> + MSG("Can't allocate memory for page_flag. %s\n",
>> + strerror(errno));
>> + return FALSE;
>> + }
>> + current = info->page_flag_buf[i];
>> +
>> + for (j = 1; j < NUM_BUFFERS; j++) {
>> + if ((current->next = calloc(1, sizeof(struct page_flag))) == NULL) {
>> + MSG("Can't allocate memory for page_flag. %s\n",
>> + strerror(errno));
>> + return FALSE;
>> + }
>> + current = current->next;
>> + }
>> + current->next = info->page_flag_buf[i];
>> + }
>> +
>> + /*
>> * initial fd_memory for threads
>> */
>> for (i = 0; i < info->num_threads; i++) {
>> @@ -3612,7 +3649,8 @@ initial_for_parallel()
>> void
>> free_for_parallel()
>> {
>> - int i;
>> + int i, j;
>> + struct page_flag *current;
>>
>> if (info->threads != NULL) {
>> for (i = 0; i < info->num_threads; i++) {
>> @@ -3655,6 +3693,19 @@ free_for_parallel()
>> free(info->page_data_buf);
>> }
>>
>> + if (info->page_flag_buf != NULL) {
>> + for (i = 0; i < info->num_threads; i++) {
>> + for (j = 0; j < NUM_BUFFERS; j++) {
>> + if (info->page_flag_buf[i] != NULL) {
>> + current = info->page_flag_buf[i];
>> + info->page_flag_buf[i] = current->next;
>> + free(current);
>> + }
>> + }
>> + }
>> + free(info->page_flag_buf);
>> + }
>> +
>> if (info->parallel_info == NULL)
>> return;
>>
>> @@ -7075,11 +7126,11 @@ void *
>> kdump_thread_function_cyclic(void *arg) {
>> void *retval = PTHREAD_FAIL;
>> struct thread_args *kdump_thread_args = (struct thread_args *)arg;
>> - struct page_data *page_data_buf = kdump_thread_args->page_data_buf;
>> + volatile struct page_data *page_data_buf = kdump_thread_args->page_data_buf;
>> + volatile struct page_flag *page_flag_buf = kdump_thread_args->page_flag_buf;
>> struct cycle *cycle = kdump_thread_args->cycle;
>> - int page_data_num = kdump_thread_args->page_data_num;
>> - mdf_pfn_t pfn;
>> - int index;
>> + mdf_pfn_t pfn = cycle->start_pfn;
>> + int index = kdump_thread_args->thread_num;
>> int buf_ready;
>> int dumpable;
>> int fd_memory = 0;
>> @@ -7125,47 +7176,48 @@ kdump_thread_function_cyclic(void *arg) {
>> kdump_thread_args->thread_num);
>> }
>>
>> - while (1) {
>> - /* get next pfn */
>> - pthread_mutex_lock(&info->current_pfn_mutex);
>> - pfn = info->current_pfn;
>> - info->current_pfn++;
>> - pthread_mutex_unlock(&info->current_pfn_mutex);
>> -
>> - if (pfn >= kdump_thread_args->end_pfn)
>> - break;
>> -
>> - index = -1;
>> + /*
>> + * filtered page won't take anything
>> + * unfiltered zero page will only take a page_flag_buf
>> + * unfiltered non-zero page will take a page_flag_buf and a page_data_buf
>> + */
>> + while (pfn < cycle->end_pfn) {
>> buf_ready = FALSE;
>>
>> + pthread_mutex_lock(&info->page_data_mutex);
>> + while (page_data_buf[index].used != FALSE) {
>> + index = (index + 1) % info->num_buffers;
>> + }
>> + page_data_buf[index].used = TRUE;
>> + pthread_mutex_unlock(&info->page_data_mutex);
>> +
>> while (buf_ready == FALSE) {
>> pthread_testcancel();
>> -
>> - index = pfn % page_data_num;
>> -
>> - if (pfn - info->consumed_pfn > info->num_buffers)
>> + if (page_flag_buf->ready == FLAG_READY)
>> continue;
>>
>> - if (page_data_buf[index].ready != 0)
>> - continue;
>> -
>> - pthread_mutex_lock(&page_data_buf[index].mutex);
>> -
>> - if (page_data_buf[index].ready != 0)
>> - goto unlock;
>> -
>> - buf_ready = TRUE;
>> + /* get next dumpable pfn */
>> + pthread_mutex_lock(&info->current_pfn_mutex);
>> + for (pfn = info->current_pfn; pfn < cycle->end_pfn; pfn++) {
>> + dumpable = is_dumpable(
>> + info->fd_bitmap ? &bitmap_parallel : info->bitmap2,
>> + pfn,
>> + cycle);
>> + if (dumpable)
>> + break;
>> + }
>> + info->current_pfn = pfn + 1;
>>
>> - page_data_buf[index].pfn = pfn;
>> - page_data_buf[index].ready = 1;
>> + page_flag_buf->pfn = pfn;
>> + page_flag_buf->ready = FLAG_FILLING;
>> + pthread_mutex_unlock(&info->current_pfn_mutex);
>> + sem_post(&info->page_flag_buf_sem);
>>
>> - dumpable = is_dumpable(
>> - info->fd_bitmap ? &bitmap_parallel : info->bitmap2,
>> - pfn,
>> - cycle);
>> - page_data_buf[index].dumpable = dumpable;
>> - if (!dumpable)
>> - goto unlock;
>> + if (pfn >= cycle->end_pfn) {
>> + info->current_pfn = cycle->end_pfn;
>> + page_data_buf[index].used = FALSE;
>> + break;
>> + }
>>
>> if (!read_pfn_parallel(fd_memory, pfn, buf,
>> &bitmap_memory_parallel,
>> @@ -7178,11 +7230,11 @@ kdump_thread_function_cyclic(void *arg) {
>>
>> if ((info->dump_level & DL_EXCLUDE_ZERO)
>> && is_zero_page(buf, info->page_size)) {
>> - page_data_buf[index].zero = TRUE;
>> - goto unlock;
>> + page_flag_buf->zero = TRUE;
>> + goto next;
>> }
>>
>> - page_data_buf[index].zero = FALSE;
>> + page_flag_buf->zero = FALSE;
>>
>> /*
>> * Compress the page data.
>> @@ -7210,6 +7262,7 @@ kdump_thread_function_cyclic(void *arg) {
>> page_data_buf[index].flags =
>> DUMP_DH_COMPRESSED_LZO;
>> page_data_buf[index].size = size_out;
>> +
>> memcpy(page_data_buf[index].buf, buf_out, size_out);
>> #endif
>> #ifdef USESNAPPY
>> @@ -7232,12 +7285,14 @@ kdump_thread_function_cyclic(void *arg) {
>> page_data_buf[index].size = info->page_size;
>> memcpy(page_data_buf[index].buf, buf, info->page_size);
>> }
>> -unlock:
>> - pthread_mutex_unlock(&page_data_buf[index].mutex);
>> + page_flag_buf->index = index;
>> + buf_ready = TRUE;
>> +next:
>> + page_flag_buf->ready = FLAG_READY;
>> + page_flag_buf = page_flag_buf->next;
>>
>> }
>> }
>> -
>> retval = NULL;
>>
>> fail:
>> @@ -7265,14 +7320,15 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
>> struct page_desc pd;
>> struct timeval tv_start;
>> struct timeval last, new;
>> - unsigned long long consuming_pfn;
>> pthread_t **threads = NULL;
>> struct thread_args *kdump_thread_args = NULL;
>> void *thread_result;
>> - int page_data_num;
>> + int page_buf_num;
>> struct page_data *page_data_buf = NULL;
>> int i;
>> int index;
>> + int end_count, consuming, check_count;
>> + mdf_pfn_t current_pfn, temp_pfn;
>>
>> if (info->flag_elf_dumpfile)
>> return FALSE;
>> @@ -7284,13 +7340,6 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
>> goto out;
>> }
>>
>> - res = pthread_mutex_init(&info->consumed_pfn_mutex, NULL);
>> - if (res != 0) {
>> - ERRMSG("Can't initialize consumed_pfn_mutex. %s\n",
>> - strerror(res));
>> - goto out;
>> - }
>> -
>> res = pthread_mutex_init(&info->filter_mutex, NULL);
>> if (res != 0) {
>> ERRMSG("Can't initialize filter_mutex. %s\n", strerror(res));
>> @@ -7314,36 +7363,23 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
>> end_pfn = cycle->end_pfn;
>>
>> info->current_pfn = start_pfn;
>> - info->consumed_pfn = start_pfn - 1;
>>
>> threads = info->threads;
>> kdump_thread_args = info->kdump_thread_args;
>>
>> - page_data_num = info->num_buffers;
>> + page_buf_num = info->num_buffers;
>> page_data_buf = info->page_data_buf;
>> + pthread_mutex_init(&info->page_data_mutex, NULL);
>> + sem_init(&info->page_flag_buf_sem, 0, 0);
>>
>> - for (i = 0; i < page_data_num; i++) {
>> - /*
>> - * producer will use pfn in page_data_buf to decide the
>> - * consumed pfn
>> - */
>> - page_data_buf[i].pfn = start_pfn - 1;
>> - page_data_buf[i].ready = 0;
>> - res = pthread_mutex_init(&page_data_buf[i].mutex, NULL);
>> - if (res != 0) {
>> - ERRMSG("Can't initialize mutex of page_data_buf. %s\n",
>> - strerror(res));
>> - goto out;
>> - }
>> - }
>> + for (i = 0; i < page_buf_num; i++)
>> + page_data_buf[i].used = FALSE;
>>
>> for (i = 0; i < info->num_threads; i++) {
>> kdump_thread_args[i].thread_num = i;
>> kdump_thread_args[i].len_buf_out = len_buf_out;
>> - kdump_thread_args[i].start_pfn = start_pfn;
>> - kdump_thread_args[i].end_pfn = end_pfn;
>> - kdump_thread_args[i].page_data_num = page_data_num;
>> kdump_thread_args[i].page_data_buf = page_data_buf;
>> + kdump_thread_args[i].page_flag_buf = info->page_flag_buf[i];
>> kdump_thread_args[i].cycle = cycle;
>>
>> res = pthread_create(threads[i], NULL,
>> @@ -7356,55 +7392,88 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
>> }
>> }
>>
>> - consuming_pfn = start_pfn;
>> - index = -1;
>> + end_count = 0;
>> + while (1) {
>> + consuming = 0;
>> + check_count = 0;
>>
>> - gettimeofday(&last, NULL);
>> + /*
>> + * The basic idea is producer producing page and consumer writing page.
>> + * Each producer have a page_flag_buf list which is used for storing page's description.
>> + * The size of page_flag_buf is little so it won't take too much memory.
>> + * And all producers will share a page_data_buf array which is used for storing page's compressed data.
>> + * The main thread is the consumer. It will find the next pfn and write it into file.
>> + * The next pfn is smallest pfn in all page_flag_buf.
>> + */
>> + sem_wait(&info->page_flag_buf_sem);
>> + gettimeofday(&last, NULL);
>> + while (1) {
>> + current_pfn = end_pfn;
>>
>> - while (consuming_pfn < end_pfn) {
>> - index = consuming_pfn % page_data_num;
>> + /*
>> + * page_flag_buf is in circular linked list.
>> + * The array info->page_flag_buf[] records the current page_flag_buf in each thread's
>> + * page_flag_buf list.
>> + * consuming is used for recording in which thread the pfn is the smallest.
>> + * current_pfn is used for recording the value of pfn when checking the pfn.
>> + */
>> + for (i = 0; i < info->num_threads; i++) {
>> + if (info->page_flag_buf[i]->ready == FLAG_UNUSED)
>> + continue;
>> + temp_pfn = info->page_flag_buf[i]->pfn;
>>
>> - gettimeofday(&new, NULL);
>> - if (new.tv_sec - last.tv_sec > WAIT_TIME) {
>> - ERRMSG("Can't get data of pfn %llx.\n", consuming_pfn);
>> - goto out;
>> - }
>> + /*
>> + * count how many threads have reached the end.
>> + */
>> + if (temp_pfn >= end_pfn) {
>> + info->page_flag_buf[i]->ready = FLAG_UNUSED;
>> + end_count++;
>> + continue;
>> + }
>>
>> - /*
>> - * check pfn first without mutex locked to reduce the time
>> - * trying to lock the mutex
>> - */
>> - if (page_data_buf[index].pfn != consuming_pfn)
>> - continue;
>> + if (current_pfn < temp_pfn)
>> + continue;
>>
>> - if (pthread_mutex_trylock(&page_data_buf[index].mutex) != 0)
>> - continue;
>> + check_count++;
>> + consuming = i;
>> + current_pfn = temp_pfn;
>> + }
>>
>> - /* check whether the found one is ready to be consumed */
>> - if (page_data_buf[index].pfn != consuming_pfn ||
>> - page_data_buf[index].ready != 1) {
>> - goto unlock;
>> + /*
>> + * If all the threads have reached the end, we will finish writing.
>> + */
>> + if (end_count >= info->num_threads)
>> + goto finish;
>> +
>> + /*
>> + * If the page_flag_buf is not ready, the pfn recorded may be changed.
>> + * So we should recheck.
>> + */
>> + if (info->page_flag_buf[consuming]->ready != FLAG_READY) {
>> + gettimeofday(&new, NULL);
>> + if (new.tv_sec - last.tv_sec > WAIT_TIME) {
>> + ERRMSG("Can't get data of pfn.\n");
>> + goto out;
>> + }
>> + continue;
>> + }
>> +
>> + if (current_pfn == info->page_flag_buf[consuming]->pfn)
>> + break;
>> }
>>
>> if ((num_dumped % per) == 0)
>> print_progress(PROGRESS_COPY, num_dumped, info->num_dumpable);
>>
>> - /* next pfn is found, refresh last here */
>> - last = new;
>> - consuming_pfn++;
>> - info->consumed_pfn++;
>> - page_data_buf[index].ready = 0;
>> -
>> - if (page_data_buf[index].dumpable == FALSE)
>> - goto unlock;
>> -
>> num_dumped++;
>>
>> - if (page_data_buf[index].zero == TRUE) {
>> +
>> + if (info->page_flag_buf[consuming]->zero == TRUE) {
>> if (!write_cache(cd_header, pd_zero, sizeof(page_desc_t)))
>> goto out;
>> pfn_zero++;
>> } else {
>> + index = info->page_flag_buf[consuming]->index;
>> pd.flags = page_data_buf[index].flags;
>> pd.size = page_data_buf[index].size;
>> pd.page_flags = 0;
>> @@ -7420,12 +7489,12 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
>> */
>> if (!write_cache(cd_page, page_data_buf[index].buf, pd.size))
>> goto out;
>> -
>> + page_data_buf[index].used = FALSE;
>> }
>> -unlock:
>> - pthread_mutex_unlock(&page_data_buf[index].mutex);
>> + info->page_flag_buf[consuming]->ready = FLAG_UNUSED;
>> + info->page_flag_buf[consuming] = info->page_flag_buf[consuming]->next;
>> }
>> -
>> +finish:
>> ret = TRUE;
>> /*
>> * print [100 %]
>> @@ -7463,15 +7532,9 @@ out:
>> }
>> }
>>
>> - if (page_data_buf != NULL) {
>> - for (i = 0; i < page_data_num; i++) {
>> - pthread_mutex_destroy(&page_data_buf[i].mutex);
>> - }
>> - }
>> -
>> + sem_destroy(&info->page_flag_buf_sem);
>> pthread_rwlock_destroy(&info->usemmap_rwlock);
>> pthread_mutex_destroy(&info->filter_mutex);
>> - pthread_mutex_destroy(&info->consumed_pfn_mutex);
>> pthread_mutex_destroy(&info->current_pfn_mutex);
>>
>> return ret;
>> @@ -7564,6 +7627,7 @@ write_kdump_pages_cyclic(struct cache_data *cd_header, struct cache_data *cd_pag
>> num_dumped++;
>> if (!read_pfn(pfn, buf))
>> goto out;
>> +
>> filter_data_buffer(buf, pfn_to_paddr(pfn), info->page_size);
>>
>> /*
>> 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;
>> --
>> 1.8.3.1
>>
>>
>>
>>
>> _______________________________________________
>> kexec mailing list
>> kexec at lists.infradead.org
>> http://lists.infradead.org/mailman/listinfo/kexec
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