Hi, Minfei > -----Original Message----- > From: kexec [mailto:kexec-bounces at lists.infradead.org] On Behalf Of Minoru Usui > Sent: Monday, March 07, 2016 4:37 PM > To: Minfei Huang <mhuang at redhat.com>; Zhou Wenjian <zhouwj-fnst at cn.fujitsu.com> > Cc: kexec at lists.infradead.org > Subject: Re: [PATCH v3] Improve the performance of --num-threads -d 31 > > Hi, Minfei, Zhou > > > -----Original Message----- > > From: kexec [mailto:kexec-bounces at lists.infradead.org] On Behalf Of Minfei Huang > > Sent: Monday, March 07, 2016 4:05 PM > > To: Zhou Wenjian <zhouwj-fnst at cn.fujitsu.com> > > Cc: kexec at lists.infradead.org > > Subject: Re: [PATCH v3] Improve the performance of --num-threads -d 31 > > > > Hi, Wenjian. > > > > Since your patch applied Minoru Usui's draft patch, I have vierified it. > > And it works well under 4T memory. > > > > applied makedumpfile with option -d 31 > > real 3m48.681s > > > > applied makedumpfile with option -d 31 --num-threads 32 > > real 3m3.533s > > > > original makedumpfile with option -d 31 > > real 3m57.163s > > > > Now with or without option --num-thread, it takes almost same time. > > Thank you for your test on big memory machine. > I am relieved to see your test results. I'm sorry, I may be misunderstood. Is above result is Zhou's v3 patch or v2 + my patch? If above result is Zhou's v3 patch, could you test v2 + my patch? Thanks Minoru Usui > Zhou, my patch may not be sophisticated, > but getting mutex logic is robust, it works well and its performance is not bad. > I think it reaches the goal of the original purpose. > I understand you don't like getting mutex, but if you are debugging now, could you apply my approach? > > Thanks, > Minoru Usui > > > > Thanks > > Minfei > > > > On 03/04/16 at 04:35pm, Zhou Wenjian wrote: > > > 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 | 300 +++++++++++++++++++++++++++++++++++---------------------- > > > makedumpfile.h | 33 ++++--- > > > 2 files changed, 203 insertions(+), 130 deletions(-) > > > > > > diff --git a/makedumpfile.c b/makedumpfile.c > > > index fa0b779..d75f7f7 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) > > > - continue; > > > - > > > - if (page_data_buf[index].ready != 0) > > > + if (page_flag_buf->ready == FLAG_READY) > > > continue; > > > > > > - pthread_mutex_lock(&page_data_buf[index].mutex); > > > - > > > - if (page_data_buf[index].ready != 0) > > > - goto unlock; > > > + /* 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; > > > > > > - buf_ready = TRUE; > > > + page_flag_buf->pfn = pfn; > > > + page_flag_buf->ready = FLAG_FILLING; > > > + pthread_mutex_unlock(&info->current_pfn_mutex); > > > > > > - page_data_buf[index].pfn = pfn; > > > - page_data_buf[index].ready = 1; > > > > > > - 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 +7363,22 @@ 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); > > > > > > - 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 +7391,94 @@ 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. > > > + */ > > > + 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; > > > + } > > > + > > > + /* > > > + * If all the threads have reached the end, we will finish writing. > > > + */ > > > + if (end_count >= info->num_threads) > > > + goto finish; > > > + > > > + /* > > > + * Since it has the probabilty that there is no page_flag_buf being ready, > > > + * we should recheck if it happens. > > > + */ > > > + if (check_count == 0) > > > + continue; > > > + > > > + /* > > > + * 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; > > > + } > > > > > > - /* 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 (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 +7494,12 @@ 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 +7537,8 @@ out: > > > } > > > } > > > > > > - if (page_data_buf != NULL) { > > > - for (i = 0; i < page_data_num; i++) { > > > - pthread_mutex_destroy(&page_data_buf[i].mutex); > > > - } > > > - } > > > - > > > 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 +7631,7 @@ 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..5865827 100644 > > > --- a/makedumpfile.h > > > +++ b/makedumpfile.h > > > @@ -977,7 +977,7 @@ 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 +985,33 @@ 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 +1300,11 @@ struct DumpInfo { > > > pthread_t **threads; > > > struct thread_args *kdump_thread_args; > > > struct page_data *page_data_buf; > > > + struct page_flag **page_flag_buf; > > > 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 > > > > _______________________________________________ > > kexec mailing list > > kexec at lists.infradead.org > > http://lists.infradead.org/mailman/listinfo/kexec > > _______________________________________________ > kexec mailing list > kexec at lists.infradead.org > http://lists.infradead.org/mailman/listinfo/kexec
