[PATCH V5] Improve the performance of --num-threads -d 31
Minfei Huang
mhuang at redhat.com
Tue Apr 12 21:53:25 PDT 2016
On 04/12/16 at 11:17am, "Zhou, Wenjian/周文剑" wrote:
> Hello Atsushi and Minfei,
>
Hi, Zhou.
There is no machine available now. I will retest it, once I get one.
Thanks
Minfei
> How about this version?
>
> --
> Thanks
> Zhou
>
> On 04/08/2016 04:20 PM, Zhou Wenjian wrote:
> >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 <min-usui at ti.jp.nec.com>
> >Signed-off-by: Zhou Wenjian <zhouwj-fnst at cn.fujitsu.com>
> >---
> > makedumpfile.c | 306 +++++++++++++++++++++++++++++++++++----------------------
> > makedumpfile.h | 35 ++++---
> > 2 files changed, 210 insertions(+), 131 deletions(-)
> >
> >diff --git a/makedumpfile.c b/makedumpfile.c
> >index fa0b779..52811d5 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);
> >
> >@@ -3562,8 +3563,10 @@ initial_for_parallel()
> > - MAP_REGION * info->num_threads) * 0.6;
> >
> > 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 +3591,36 @@ 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 +3645,8 @@ 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 +3689,19 @@ 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 +7122,11 @@ 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 +7172,48 @@ 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 +7226,11 @@ 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 +7258,7 @@ 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 +7281,14 @@ 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 +7316,15 @@ 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 +7336,6 @@ 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 +7359,23 @@ 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 +7388,86 @@ 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 +7483,12 @@ 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 +7526,9 @@ 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 +7621,7 @@ 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);
> >
> > /*
> >@@ -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);
> >+
> >+ info->num_threads = MIN(info->num_threads % 2, limit_size % MAP_REGION);
> >+ MSG("--num_threads is set to %d.\n", info->num_threads);
> >+ }
> >+
> >+ limit_size = limit_size - MAP_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..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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