[CRIU] [PATCH] deduplication: bunch neighbour data to punch together
Pavel Tikhomirov
snorcht at gmail.com
Fri Mar 7 00:24:21 PST 2014
2014-03-04 9:30 GMT+04:00 Pavel Tikhomirov <snorcht at gmail.com>:
> 2014-03-03 17:51 GMT+04:00 Tikhomirov Pavel <snorcht at gmail.com>:
>
> when decide that data is no longer needed, there are two cases:
>> 1. if data neighbours previous block of "no needed" data, extend bunch
>> block(it holds begining and size of concequent "no needed" data) by
>> length of curent block and go next.
>> 2. if data not neighbours bunch block(or bunch block size is bigger
>> than MAX_BUNCH_SIZE), than punch bunch block and set bunch block
>> to curent block.
>>
>> in the end make cleanup to punch last bunch block.
>>
>> Signed-off-by: Tikhomirov Pavel <snorcht at gmail.com>
>> ---
>> cr-dedup.c | 34 ++++++++++++++++++++++++++--------
>> include/page-read.h | 5 ++++-
>> page-read.c | 14 +++++++++++++-
>> 3 files changed, 43 insertions(+), 10 deletions(-)
>>
>> diff --git a/cr-dedup.c b/cr-dedup.c
>> index 6f059d1..9d269d2 100644
>> --- a/cr-dedup.c
>> +++ b/cr-dedup.c
>> @@ -7,6 +7,8 @@
>> #include "page-read.h"
>> #include "restorer.h"
>>
>> +#define MAX_BUNCH_SIZE 256
>> +
>> static int cr_dedup_one_pagemap(int pid);
>>
>> int cr_dedup(void)
>> @@ -101,15 +103,30 @@ exit:
>> return 0;
>> }
>>
>> -int punch_hole(int fd, unsigned long off, unsigned long len)
>> +int punch_hole(int fd, unsigned long off, unsigned long len,
>> + struct iovec * bunch, bool cleanup, int pr_id)
>> {
>> int ret;
>> - pr_debug("Punch!/%lu/%lu/\n", off, len);
>> - ret = fallocate(fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
>> - off, len);
>> - if (ret != 0) {
>> - pr_perror("Error punching hole");
>> - return -1;
>> +
>> + if ((unsigned long)bunch->iov_base + bunch->iov_len == off &&
>> !cleanup
>> + && bunch->iov_len < MAX_BUNCH_SIZE * PAGE_SIZE) {
>> + pr_debug("pr%d:Extend bunch len from %lx to %lx\n", pr_id,
>> + bunch->iov_len, bunch->iov_len + len);
>> + bunch->iov_len += len;
>> + } else {
>> + if (bunch->iov_len > 0) {
>> + pr_debug("Punch!/%lx/%lx/\n", (unsigned
>> long)bunch->iov_base, bunch->iov_len);
>> + ret = fallocate(fd, FALLOC_FL_PUNCH_HOLE |
>> FALLOC_FL_KEEP_SIZE,
>> + (unsigned long)bunch->iov_base,
>> bunch->iov_len);
>> + if (ret != 0) {
>> + pr_perror("Error punching hole");
>> + return -1;
>> + }
>> + }
>> + bunch->iov_base = (void *)off;
>> + bunch->iov_len = len;
>> + pr_debug("pr%d:New bunch/%lx/%lx/\n", pr_id,
>> + (unsigned long)bunch->iov_base, bunch->iov_len);
>> }
>> return 0;
>> }
>> @@ -146,7 +163,8 @@ int dedup_one_iovec(struct page_read *pr, struct
>> iovec *iov)
>> piov_end = (unsigned long)piov.iov_base + piov.iov_len;
>> off_real = lseek(pr->fd_pg, 0, SEEK_CUR);
>> if (!pr->pe->in_parent) {
>> - ret = punch_hole(pr->fd_pg, off_real,
>> min(piov_end, iov_end) - off);
>> + ret = punch_hole(pr->fd_pg, off_real,
>> min(piov_end, iov_end) - off,
>> + &pr->bunch, false, pr->id);
>> if (ret == -1)
>> return ret;
>> }
>> diff --git a/include/page-read.h b/include/page-read.h
>> index 8b467c6..28435c7 100644
>> --- a/include/page-read.h
>> +++ b/include/page-read.h
>> @@ -63,6 +63,8 @@ struct page_read {
>> read_pagemap_page */
>> unsigned long cvaddr; /* vaddr we are on */
>>
>> + struct iovec bunch; /* record consequent neighbour
>> + iovecs to punch together */
>> unsigned id; /* for logging */
>> };
>>
>> @@ -72,5 +74,6 @@ extern void pagemap2iovec(PagemapEntry *pe, struct
>> iovec *iov);
>> extern int seek_pagemap_page(struct page_read *pr, unsigned long vaddr,
>> bool warn);
>>
>> extern int dedup_one_iovec(struct page_read *pr, struct iovec *iov);
>> -extern int punch_hole(int fd, unsigned long off, unsigned long len);
>> +extern int punch_hole(int fd, unsigned long off, unsigned long len,
>> + struct iovec * bunch, bool cleanup, int pr_id);
>> #endif /* __CR_PAGE_READ_H__ */
>> diff --git a/page-read.c b/page-read.c
>> index e2514d6..0fd3464 100644
>> --- a/page-read.c
>> +++ b/page-read.c
>> @@ -149,7 +149,8 @@ static int read_pagemap_page(struct page_read *pr,
>> unsigned long vaddr, void *bu
>> }
>>
>> if (opts.auto_dedup) {
>> - ret = punch_hole(pr->fd_pg, current_vaddr,
>> (unsigned int)PAGE_SIZE);
>> + ret = punch_hole(pr->fd_pg, current_vaddr,
>> (unsigned int)PAGE_SIZE,
>> + &pr->bunch, false, pr->id);
>> if (ret == -1) {
>> return -1;
>> }
>> @@ -163,6 +164,15 @@ static int read_pagemap_page(struct page_read *pr,
>> unsigned long vaddr, void *bu
>>
>> static void close_page_read(struct page_read *pr)
>> {
>> + int ret;
>> + if (pr->bunch.iov_len > 0) {
>> + ret = punch_hole(pr->fd_pg, 0, 0, &pr->bunch, true,
>> pr->id);
>> + if (ret == -1)
>> + return;
>>
>
> Here I'm not sure if I can do something like this, and what will be better
> way to do it.
> But this place is really suitable to make cleanup. So give me an advice,
> Thanks!
>
Make close_page_read return int? Or it is unappropriate to make cleanup in
close func?
>
>
>> +
>> + pr->bunch.iov_len = 0;
>> + }
>> +
>> if (pr->parent) {
>> close_page_read(pr->parent);
>> xfree(pr->parent);
>> @@ -207,6 +217,8 @@ err_cl:
>> int open_page_read_at(int dfd, int pid, struct page_read *pr, int flags)
>> {
>> pr->pe = NULL;
>> + pr->bunch.iov_len = 0;
>> + pr->bunch.iov_base = NULL;
>>
>> pr->fd = open_image_at(dfd, CR_FD_PAGEMAP, O_RSTR, (long)pid);
>> if (pr->fd < 0) {
>> --
>> 1.8.3.2
>>
>>
>
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