Hi, Zhou. This patch works for me. I have tested serveal rounds using option --num_threads 1,2,4,8,16,32,64 and 128, and all of results look fine.
Thanks Minfei Tested-by: Minfei Huang <[email protected]> Thanks Minfei On 04/18/16 at 09:05am, Zhou Wenjian wrote: > v8: > 1. check if info->num_threads equals 0 > v7: > 1. fix a bug pointed by Minfei Huang > v6: > 1. address Atsushi Kumagai's comments about calculating and reserving > memory > v5: > 1. remove unused variable check_out > 2. reset num_threads if memory is not enough > 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 <[email protected]> > Signed-off-by: Zhou Wenjian <[email protected]> > --- > makedumpfile.c | 325 > ++++++++++++++++++++++++++++++++++----------------------- > makedumpfile.h | 38 ++++--- > 2 files changed, 215 insertions(+), 148 deletions(-) > > diff --git a/makedumpfile.c b/makedumpfile.c > index fa0b779..275f35d 100644 > --- a/makedumpfile.c > +++ b/makedumpfile.c > @@ -3481,9 +3481,8 @@ initial_for_parallel() > { > unsigned long len_buf_out; > 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); > > @@ -3553,20 +3552,7 @@ initial_for_parallel() > #endif > } > > - /* > - * get a safe number of page_data > - */ > - page_data_buf_size = MAX(len_buf_out, info->page_size); > - > - limit_size = (get_free_memory_size() > - - MAP_REGION * info->num_threads) * 0.6; > - > - page_data_num = limit_size / page_data_buf_size; > - > - info->num_buffers = MIN(NUM_BUFFERS, page_data_num); > - > - DEBUG_MSG("Number of struct page_data for produce/consume: %d\n", > - info->num_buffers); > + info->num_buffers = PAGE_DATA_NUM * info->num_threads; > > /* > * allocate memory for page_data > @@ -3579,6 +3565,7 @@ initial_for_parallel() > } > memset(info->page_data_buf, 0, sizeof(struct page_data) * > info->num_buffers); > > + page_data_buf_size = MAX(len_buf_out, info->page_size); > for (i = 0; i < info->num_buffers; i++) { > if ((info->page_data_buf[i].buf = malloc(page_data_buf_size)) > == NULL) { > MSG("Can't allocate memory for buf of page_data_buf. > %s\n", > @@ -3588,6 +3575,36 @@ 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 < PAGE_FLAG_NUM; 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 +3629,8 @@ 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 +3673,19 @@ 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 < PAGE_FLAG_NUM; 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 +7106,11 @@ 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 +7156,48 @@ 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 +7210,11 @@ 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. > @@ -7232,12 +7264,14 @@ 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 +7299,15 @@ 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; > + mdf_pfn_t current_pfn, temp_pfn; > > if (info->flag_elf_dumpfile) > return FALSE; > @@ -7284,13 +7319,6 @@ 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 +7342,23 @@ 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 +7371,86 @@ write_kdump_pages_parallel_cyclic(struct cache_data > *cd_header, > } > } > > - consuming_pfn = start_pfn; > - index = -1; > + end_count = 0; > + while (1) { > + consuming = 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; > + 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 +7466,12 @@ 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 +7509,9 @@ 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 +7604,7 @@ 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); > > /* > @@ -10201,7 +10242,6 @@ out: > return free_size; > } > > - > /* > * Choose the less value of the three below as the size of cyclic buffer. > * - the size enough for storing the 1st or 2nd bitmap for the whole of > vmcore > @@ -10223,6 +10263,25 @@ 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 (info->num_threads > 0) { > + if (limit_size <= maximum_size) { > + MSG("There isn't enough memory for multi-threads.\n"); > + info->num_threads = 0; > + } > + else if ((limit_size - maximum_size) / info->num_threads < > THREAD_REGION) { > + MSG("There isn't enough memory for %d threads.\n", > info->num_threads); > + info->num_threads = (limit_size - maximum_size) / > THREAD_REGION; > + MSG("--num_threads is set to %d.\n", info->num_threads); > + > + limit_size = limit_size - THREAD_REGION * > info->num_threads; > + } > + } > + > /* 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..322d31b 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 > @@ -974,10 +975,11 @@ typedef unsigned long long int ulonglong; > * for parallel process > */ > > -#define PAGE_DATA_NUM (50) > +#define PAGE_FLAG_NUM (20) > +#define PAGE_DATA_NUM (5) > #define WAIT_TIME (60 * 10) > #define PTHREAD_FAIL ((void *)-2) > -#define NUM_BUFFERS (50) > +#define THREAD_REGION (200 * 1024) > > struct mmap_cache { > char *mmap_buf; > @@ -985,28 +987,33 @@ 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 +1302,12 @@ 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 > [email protected] > http://lists.infradead.org/mailman/listinfo/kexec _______________________________________________ kexec mailing list [email protected] http://lists.infradead.org/mailman/listinfo/kexec
