[PATCH v1] Improve the performance of --num-threads -d 31
Minoru Usui
min-usui at ti.jp.nec.com
Mon Feb 22 23:46:27 PST 2016
Hi,
> -----Original Message-----
> From: "Zhou, Wenjian/周文剑" [mailto:zhouwj-fnst at cn.fujitsu.com]
> Sent: Tuesday, February 23, 2016 12:53 PM
> To: Usui Minoru(碓井 成) <min-usui at ti.jp.nec.com>; kexec at lists.infradead.org
> Subject: Re: [PATCH v1] Improve the performance of --num-threads -d 31
>
> On 02/23/2016 10:16 AM, Minoru Usui wrote:
> > Hello Zhou
> >
> > I'm sorry for late reply, too.
> >
> >> -----Original Message-----
> >> From: "Zhou, Wenjian/周文剑" [mailto:zhouwj-fnst at cn.fujitsu.com]
> >> Sent: Monday, February 15, 2016 11:15 AM
> >> To: Usui Minoru(碓井 成) <min-usui at ti.jp.nec.com>; kexec at lists.infradead.org
> >> Subject: Re: [PATCH v1] Improve the performance of --num-threads -d 31
> >>
> >> Hello Usui,
> >>
> >> Thanks very much for your comments.
> >> And sorry for the late reply.
> >>
> >> See below.
> >>
> >> On 02/08/2016 01:00 PM, Minoru Usui wrote:
> >>> Hello,
> >>>
> >>>> -----Original Message-----
> >>>> From: kexec [mailto:kexec-bounces at lists.infradead.org] On Behalf Of Minoru Usui
> >>>> Sent: Thursday, February 04, 2016 8:52 AM
> >>>> To: Zhou Wenjian <zhouwj-fnst at cn.fujitsu.com>; kexec at lists.infradead.org
> >>>> Subject: Re: [PATCH v1] Improve the performance of --num-threads -d 31
> >>>>
> >>>> Hi, Zhou
> >>>>
> >>>> I have some comments.
> >>>> I'm sorry if I have misunderstood your code.
> >>>>
> >>>>> -----Original Message-----
> >>>>> From: kexec [mailto:kexec-bounces at lists.infradead.org] On Behalf Of Zhou Wenjian
> >>>>> Sent: Monday, February 01, 2016 3:22 PM
> >>>>> To: kexec at lists.infradead.org
> >>>>> Subject: [PATCH v1] Improve the performance of --num-threads -d 31
> >>>>>
> >>>>> v1:
> >>>>> 1. change page_flag.ready's value to enum
> >>>>> 2. change the patch description
> >>>>> 3. cleanup some codes
> >>>>> 4. fix a bug in cyclic mode
> >>>>>
> >>>>> 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: Zhou Wenjian <zhouwj-fnst at cn.fujitsu.com>
> >>>>> ---
> >>>>> makedumpfile.c | 258 ++++++++++++++++++++++++++++++++++++++-------------------
> >>>>> makedumpfile.h | 31 ++++---
> >>>>> 2 files changed, 193 insertions(+), 96 deletions(-)
> >>>>>
> >>>>> diff --git a/makedumpfile.c b/makedumpfile.c
> >>>>> index fa0b779..0ecd065 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] = malloc(sizeof(struct page_flag))) == NULL) {
> >>>>
> >>>> Fist element of struct page_flag in circular list is allocated by malloc(),
> >>>> but other elements are allocated by calloc().(see below)
> >>>> I think both elements should be allocated by calloc().
> >>>>
> >>
> >> Yes, you are right.
> >> I have made a mistake.
> >>
> >>>>> + MSG("Can't allocate memory for page_flag_buf. %s\n",
> >>>>> + strerror(errno));
> >>>>> + return FALSE;
> >>>>> + }
> >>>>> + current = info->page_flag_buf[i];
> >>>>> +
> >>>>> + for (j = 1; j < NUM_BUFFERS; j++) {
> >>>>> + if ((current->next = calloc(0, sizeof(struct page_flag))) == NULL) {
> >>>>> + MSG("Can't allocate memory for data of page_data_buf. %s\n",
> >>>>> + strerror(errno));
> >>>>> + return FALSE;
> >>>>> + }
> >>>>
> >>>>
> >>>> First argument of calloc() should be 1, not 0.
> >>>> And there is typo in error message.
> >>>> Allocated element is not page_data_buf.
> >>>>
> >>
> >> I agree.
> >>
> >>>>> + 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;
> >>>>>
> >>>>> @@ -7076,10 +7123,10 @@ 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;
> >>>>> + 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;
> >>>>> + int index = kdump_thread_args->thread_num;
> >>>>> int buf_ready;
> >>>>> int dumpable;
> >>>>> int fd_memory = 0;
> >>>>> @@ -7125,47 +7172,47 @@ 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);
> >>>>> + /*
> >>>>> + * 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 (page_flag_buf->pfn < kdump_thread_args->end_pfn) {
> >>>>
> >>>> At first, page_flag_buf->pfn is not initialized.
> >>>> I think this block should be replaced with the following code.
> >>>>
> >>>> ===
> >>>> do {
> >>>> :
> >>>> } while(page_flag_buf->pfn < kdump_thread_args->end_pfn)
> >>>> ===
> >>>
> >>> I'm sorry, above suggestion is meaningless in terms of page_flag_buf->pfn is uninitialized.
> >>> It should be replaced like following.
> >>>
> >>> ===
> >>> while (1) {
> >>> :
> >>> while (buf_ready == FALSE) {
> >>> :
> >>> if (pfn >= kdump_thread_args->end_pfn) {
> >>> :
> >>> goto finish;
> >>> }
> >>> :
> >>> }
> >>> :
> >>> }
> >>> finish:
> >>> ===
> >>>
> >>
> >> page_flag_buf is allocated by calloc().
> >> The page_flag_buf->pfn's value is 0.
> >> So I think it is not necessary to modify the code.
> >>
> >>> Thanks,
> >>> Minoru Usui
> >>>
> >>>
> >>>>> + buf_ready = FALSE;
> >>>>>
> >>>>> - if (pfn >= kdump_thread_args->end_pfn)
> >>>>> - break;
> >>>>> + while (page_data_buf[index].used != 0 ||
> >>>>> + pthread_mutex_trylock(&page_data_buf[index].mutex) != 0)
> >>>>> + index = (index + 1) % info->num_buffers;
> >>>>>
> >>>>> - index = -1;
> >>>>> - buf_ready = FALSE;
> >>>>> + page_data_buf[index].used = 1;
> >>>>
> >>>> "1" is a magic number.
> >>>> It should be changed TRUE or FALSE.
> >>>>
> >>
> >> I see.
> >>
> >>>>> 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;
> >>>>
> >>>> At first, page_flag_buf->ready is uninitialized, too.
> >>>> Should it be initialized in head part of this function, even if FLAG_UNUSED is defined 0?
> >>>>
> >>>>
> >>
> >> The same topic as the page_flag_buf is allocated by calloc().
> >>
> >>>>>
> >>>>> - if (page_data_buf[index].ready != 0)
> >>>>> - continue;
> >>>>> -
> >>>>> - pthread_mutex_lock(&page_data_buf[index].mutex);
> >>>>> + /* get next pfn */
> >>>>> + pthread_mutex_lock(&info->current_pfn_mutex);
> >>>>> + pfn = info->current_pfn;
> >>>>> + info->current_pfn++;
> >>>>> + page_flag_buf->ready = FLAG_FILLING;
> >>>>> + pthread_mutex_unlock(&info->current_pfn_mutex);
> >>>>>
> >>>>> - if (page_data_buf[index].ready != 0)
> >>>>> - goto unlock;
> >>>>> + page_flag_buf->pfn = pfn;
> >>>>
> >>>> It set FLAG_FILLING to page_flag_buf->ready before setting pfn to page_flag_buf->pfn.
> >>>> But consumer gets page_flag_buf->pfn after checking page_flag_buf->ready != FLAG_UNUSED
> >>>> in getting minimum pfn of each thread block.
> >>>> Should it set page_flag_buf->pfn first?
> >>>>
> >>
> >> Have you noticed the following code in the consumer?
> >> <cut>
> >> if (current_pfn == info->page_flag_buf[consuming]->pfn)
> >> break;
> >> <cut>
> >
> > No, I pointed following code.
> > This part accesses info->page_flag_buf[i]->ready, then it accesses info->page_flag_buf[i]->pfn immediately.
> > So, temp_pfn may be wrong pfn at this moment.
> >
> > ---
> > 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;
> > ---
> >
> >> The consumer will check if the pfn is changed after the page_flag_buf->ready turns to be FLAG_READY.
> >> So it's not important whether setting page_flag_buf->pfn first or not.
> >
> > As you said, consumer checks pfn which is changed.
> > So it works well.
> >
> >> In the other hand, even setting page_flag_buf->pfn first, if the pfn is not dumpable, the producer
> >> will also reset the page_flag_buf->pfn.
> >
> > Thank you for your explanation.
> > I didn't notice that pfn can be undumpable.
> >
> >>>>>
> >>>>> - buf_ready = TRUE;
> >>>>> -
> >>>>> - page_data_buf[index].pfn = pfn;
> >>>>> - page_data_buf[index].ready = 1;
> >>>>> + if (pfn >= kdump_thread_args->end_pfn) {
> >>>>> + page_data_buf[index].used = 0;
> >>>>> + page_flag_buf->ready = FLAG_READY;
> >>>>> + info->current_pfn--;
> >>>>> + break;
> >>>>> + }
> >>>>
> >>>> This block decrements info->current_pfn without info->current_pfn_mutex.
> >>>> I think this block should be moved into previous pthread_mutex_lock(info->current_pfn_mutex) block, so it can remove.
> >>>>
> >>
> >> Why do you think it should have current_pfn_mutex?
> >>
> >> If pfn >= kdump_thread_args->end_pfn, info->current_pfn will always larger than
> >> kdump_thread_args->end_pfn. info->current_pfn-- won't affect anything.
> >>
> >> The decrement operation is for cyclic mode.
> >>
> >>>>>
> >>>>> dumpable = is_dumpable(
> >>>>> info->fd_bitmap ? &bitmap_parallel : info->bitmap2,
> >>>>> pfn,
> >>>>> cycle);
> >>>>> - page_data_buf[index].dumpable = dumpable;
> >>>>> if (!dumpable)
> >>>>> - goto unlock;
> >>>>> + continue;
> >>>>>
> >>>>> if (!read_pfn_parallel(fd_memory, pfn, buf,
> >>>>> &bitmap_memory_parallel,
> >>>>> @@ -7178,11 +7225,11 @@ 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;
> >>>>> }
> >>>>
> >>>> First, this code gets page_data_buf, then it gets page_flag_buf.
> >>>> However, if processed pfn is zero page,
> >>>> it processes next pfn while keeping page_data_buf.
> >>>>
> >>>> I think it should get page_flag_buf, then get page_data_buf
> >>>> in order to shorten the holding period of the page_data_buf[index].mutex.
> >>>>
> >>
> >> Do you mean the following logic?
> >> 1. get the page_flag_buf first
> >> 2. if the pfn is not zero page, then get the page_data_buf.
> >
> > Yes.
> >
> >> Think about the following case.
> >> A producer get the page_flag_buf, and the pfn is not zero page.
> >> It wants to get a page_data_buf, but there is no more page_data_buf.
> >> Then ...
> >
> > It's not a problem.
> > In not zero page case, this logic needs both page_flag_buf and page_data_buf,
> > so waiting buffer is obvious when it isn't able to get page_flag_buf or page_data_buf.
> >
>
> Of course, waiting is not a problem.
> But if other page_data_bufs are all used by later pfns, it will
> wait forever. That's the problem.
I understand.
Thank you for your explanation.
Minoru Usui
> --
> Thanks
> Zhou
>
> >> Since there are several page_data_bufs, it's not a problem that each producer
> >> will always hold a page_data_buf.
> >
> > It depends on the speed of consumer and producer.
> > It's not possible to predict it.
> >
> > In zero page case, I think each producer executes more parallel theoretically
> > if page_data_buf doesn't get.
> >
> > Thanks,
> > Minoru Usui
> >
> >>
> >> Thanks again for your comments.
> >> And I will post the next version later.
> >>
> >> --
> >> Thanks
> >> Zhou
> >>
> >>>> Thanks,
> >>>> Minoru Usui
> >>>>
> >>>>>
> >>>>> - page_data_buf[index].zero = FALSE;
> >>>>> + page_flag_buf->zero = FALSE;
> >>>>>
> >>>>> /*
> >>>>> * Compress the page data.
> >>>>> @@ -7232,12 +7279,16 @@ 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;
> >>>>>
> >>>>> }
> >>>>> - }
> >>>>>
> >>>>> + pthread_mutex_unlock(&page_data_buf[index].mutex);
> >>>>> + }
> >>>>> 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, check_count;
> >>>>> + mdf_pfn_t current_pfn, temp_pfn;
> >>>>>
> >>>>> if (info->flag_elf_dumpfile)
> >>>>> return FALSE;
> >>>>> @@ -7319,16 +7371,11 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
> >>>>> 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;
> >>>>>
> >>>>> - 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;
> >>>>> + for (i = 0; i < page_buf_num; i++) {
> >>>>> + page_data_buf[i].used = 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",
> >>>>> @@ -7342,8 +7389,9 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
> >>>>> 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_buf_num = page_buf_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 +7404,94 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
> >>>>> }
> >>>>> }
> >>>>>
> >>>>> - consuming_pfn = start_pfn;
> >>>>> - index = -1;
> >>>>> + while (1) {
> >>>>> + consuming = 0;
> >>>>> + check_count = 0;
> >>>>> + end_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.
> >>>>> + */
> >>>>> + 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) {
> >>>>> + end_count++;
> >>>>> + info->page_flag_buf[i]->ready = FLAG_UNUSED;
> >>>>> + 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;
> >>>>> +
> >>>>> + /*
> >>>>> + * When we check the pfn in page_flag_buf, it may be being produced.
> >>>>> + * So we should wait until it is ready to use. And if the pfn is
> >>>>> + * different from the value when we check, we should rechoose the buf.
> >>>>> + */
> >>>>> + gettimeofday(&last, NULL);
> >>>>> + while (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;
> >>>>> + }
> >>>>> + }
> >>>>>
> >>>>> - /* 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 +7507,12 @@ 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 = 0;
> >>>>> }
> >>>>> -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 %]
> >>>>> @@ -7464,7 +7551,7 @@ out:
> >>>>> }
> >>>>>
> >>>>> if (page_data_buf != NULL) {
> >>>>> - for (i = 0; i < page_data_num; i++) {
> >>>>> + for (i = 0; i < page_buf_num; i++) {
> >>>>> pthread_mutex_destroy(&page_data_buf[i].mutex);
> >>>>> }
> >>>>> }
> >>>>> @@ -7564,6 +7651,7 @@ 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..8a9a5b2 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 +985,36 @@ 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;
> >>>>> + pthread_mutex_t mutex;
> >>>>> 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;
> >>>>> + int page_buf_num;
> >>>>> struct cycle *cycle;
> >>>>> struct page_data *page_data_buf;
> >>>>> + struct page_flag *page_flag_buf;
> >>>>> };
> >>>>>
> >>>>> /*
> >>>>> @@ -1295,6 +1303,7 @@ 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;
> >>>>> --
> >>>>> 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
> >>>
> >>>
> >>
>
>
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