* master - [device/bcache] Add bcache_max_prefetches()
@ 2018-04-23 13:51 David Teigland
0 siblings, 0 replies; 2+ messages in thread
From: David Teigland @ 2018-04-23 13:51 UTC (permalink / raw)
To: lvm-devel
Gitweb: https://sourceware.org/git/?p=lvm2.git;a=commitdiff;h=1563b936911d26c665b590f200884c9ed31ab7c3
Commit: 1563b936911d26c665b590f200884c9ed31ab7c3
Parent: c4c4acfd423323cbe8fbfbdb8c1882edb4a92b29
Author: Joe Thornber <ejt@redhat.com>
AuthorDate: Fri Feb 2 12:06:14 2018 +0000
Committer: David Teigland <teigland@redhat.com>
CommitterDate: Fri Apr 20 11:12:50 2018 -0500
[device/bcache] Add bcache_max_prefetches()
Ignore prefetches if max io is in flight.
---
lib/device/bcache.c | 23 +++++++++++++++--------
lib/device/bcache.h | 1 +
2 files changed, 16 insertions(+), 8 deletions(-)
diff --git a/lib/device/bcache.c b/lib/device/bcache.c
index 09ef6ef..4283ce5 100644
--- a/lib/device/bcache.c
+++ b/lib/device/bcache.c
@@ -216,17 +216,18 @@ static bool _engine_issue(struct io_engine *e, enum dir d, int fd,
return true;
}
-#define MAX_IO 64
+#define MAX_IO 1024
+#define MAX_EVENT 64
typedef void complete_fn(void *context, int io_error);
static bool _engine_wait(struct io_engine *e, complete_fn fn)
{
int i, r;
- struct io_event event[MAX_IO];
+ struct io_event event[MAX_EVENT];
struct control_block *cb;
memset(&event, 0, sizeof(event));
- r = io_getevents(e->aio_context, 1, MAX_IO, event, NULL);
+ r = io_getevents(e->aio_context, 1, MAX_EVENT, event, NULL);
if (r < 0) {
log_sys_warn("io_getevents");
return false;
@@ -300,6 +301,7 @@ struct bcache {
sector_t block_sectors;
uint64_t nr_data_blocks;
uint64_t nr_cache_blocks;
+ unsigned max_io;
struct io_engine *engine;
@@ -762,8 +764,8 @@ struct bcache *bcache_create(sector_t block_sectors, unsigned nr_cache_blocks)
cache->block_sectors = block_sectors;
cache->nr_cache_blocks = nr_cache_blocks;
-
- cache->engine = _engine_create(nr_cache_blocks < 1024u ? nr_cache_blocks : 1024u);
+ cache->max_io = nr_cache_blocks < MAX_IO ? nr_cache_blocks : MAX_IO;
+ cache->engine = _engine_create(cache->max_io);
if (!cache->engine) {
dm_free(cache);
return NULL;
@@ -820,16 +822,21 @@ unsigned bcache_nr_cache_blocks(struct bcache *cache)
return cache->nr_cache_blocks;
}
+unsigned bcache_max_prefetches(struct bcache *cache)
+{
+ return cache->max_io;
+}
+
void bcache_prefetch(struct bcache *cache, int fd, block_address index)
{
struct block *b = _hash_lookup(cache, fd, index);
if (!b) {
- cache->prefetches++;
-
b = _new_block(cache, fd, index);
- if (b)
+ if (b && (cache->nr_io_pending < cache->max_io)) {
+ cache->prefetches++;
_issue_read(b);
+ }
}
}
diff --git a/lib/device/bcache.h b/lib/device/bcache.h
index 5c68e3c..14204be 100644
--- a/lib/device/bcache.h
+++ b/lib/device/bcache.h
@@ -62,6 +62,7 @@ enum bcache_get_flags {
typedef uint64_t block_address;
unsigned bcache_nr_cache_blocks(struct bcache *cache);
+unsigned bcache_max_prefetches(struct bcache *cache);
/*
* Use the prefetch method to take advantage of asynchronous IO. For example,
^ permalink raw reply related [flat|nested] 2+ messages in thread
* master - [device/bcache] Add bcache_max_prefetches()
@ 2018-04-23 13:46 David Teigland
0 siblings, 0 replies; 2+ messages in thread
From: David Teigland @ 2018-04-23 13:46 UTC (permalink / raw)
To: lvm-devel
Gitweb: https://sourceware.org/git/?p=lvm2.git;a=commitdiff;h=1563b936911d26c665b590f200884c9ed31ab7c3
Commit: 1563b936911d26c665b590f200884c9ed31ab7c3
Parent: c4c4acfd423323cbe8fbfbdb8c1882edb4a92b29
Author: Joe Thornber <ejt@redhat.com>
AuthorDate: Fri Feb 2 12:06:14 2018 +0000
Committer: David Teigland <teigland@redhat.com>
CommitterDate: Fri Apr 20 11:12:50 2018 -0500
[device/bcache] Add bcache_max_prefetches()
Ignore prefetches if max io is in flight.
---
lib/device/bcache.c | 23 +++++++++++++++--------
lib/device/bcache.h | 1 +
2 files changed, 16 insertions(+), 8 deletions(-)
diff --git a/lib/device/bcache.c b/lib/device/bcache.c
index 09ef6ef..4283ce5 100644
--- a/lib/device/bcache.c
+++ b/lib/device/bcache.c
@@ -216,17 +216,18 @@ static bool _engine_issue(struct io_engine *e, enum dir d, int fd,
return true;
}
-#define MAX_IO 64
+#define MAX_IO 1024
+#define MAX_EVENT 64
typedef void complete_fn(void *context, int io_error);
static bool _engine_wait(struct io_engine *e, complete_fn fn)
{
int i, r;
- struct io_event event[MAX_IO];
+ struct io_event event[MAX_EVENT];
struct control_block *cb;
memset(&event, 0, sizeof(event));
- r = io_getevents(e->aio_context, 1, MAX_IO, event, NULL);
+ r = io_getevents(e->aio_context, 1, MAX_EVENT, event, NULL);
if (r < 0) {
log_sys_warn("io_getevents");
return false;
@@ -300,6 +301,7 @@ struct bcache {
sector_t block_sectors;
uint64_t nr_data_blocks;
uint64_t nr_cache_blocks;
+ unsigned max_io;
struct io_engine *engine;
@@ -762,8 +764,8 @@ struct bcache *bcache_create(sector_t block_sectors, unsigned nr_cache_blocks)
cache->block_sectors = block_sectors;
cache->nr_cache_blocks = nr_cache_blocks;
-
- cache->engine = _engine_create(nr_cache_blocks < 1024u ? nr_cache_blocks : 1024u);
+ cache->max_io = nr_cache_blocks < MAX_IO ? nr_cache_blocks : MAX_IO;
+ cache->engine = _engine_create(cache->max_io);
if (!cache->engine) {
dm_free(cache);
return NULL;
@@ -820,16 +822,21 @@ unsigned bcache_nr_cache_blocks(struct bcache *cache)
return cache->nr_cache_blocks;
}
+unsigned bcache_max_prefetches(struct bcache *cache)
+{
+ return cache->max_io;
+}
+
void bcache_prefetch(struct bcache *cache, int fd, block_address index)
{
struct block *b = _hash_lookup(cache, fd, index);
if (!b) {
- cache->prefetches++;
-
b = _new_block(cache, fd, index);
- if (b)
+ if (b && (cache->nr_io_pending < cache->max_io)) {
+ cache->prefetches++;
_issue_read(b);
+ }
}
}
diff --git a/lib/device/bcache.h b/lib/device/bcache.h
index 5c68e3c..14204be 100644
--- a/lib/device/bcache.h
+++ b/lib/device/bcache.h
@@ -62,6 +62,7 @@ enum bcache_get_flags {
typedef uint64_t block_address;
unsigned bcache_nr_cache_blocks(struct bcache *cache);
+unsigned bcache_max_prefetches(struct bcache *cache);
/*
* Use the prefetch method to take advantage of asynchronous IO. For example,
^ permalink raw reply related [flat|nested] 2+ messages in thread
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