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authorSebastian Huber <sebastian.huber@embedded-brains.de>2012-03-28 11:30:59 +0200
committerSebastian Huber <sebastian.huber@embedded-brains.de>2012-04-16 11:06:45 +0200
commitac50df23040e57acf577190cff7e7d6bf96ca916 (patch)
tree42359cb3d9f7f5f3e76691e4e433be1b9be0bb5c /cpukit
parentPR1908: QoS library for CBS scheduler (diff)
downloadrtems-ac50df23040e57acf577190cff7e7d6bf96ca916.tar.bz2
libblock: PR2040: Add starvation threshold
Do not use the unavailable block count as the erased blocks starvation threshold. Use instead the block count of the largest segment. This improves the starvation resolution gain of available blocks.
Diffstat (limited to 'cpukit')
-rw-r--r--cpukit/libblock/src/flashdisk.c16
1 files changed, 15 insertions, 1 deletions
diff --git a/cpukit/libblock/src/flashdisk.c b/cpukit/libblock/src/flashdisk.c
index 87e9e53e97..418c6639b1 100644
--- a/cpukit/libblock/src/flashdisk.c
+++ b/cpukit/libblock/src/flashdisk.c
@@ -177,6 +177,7 @@ typedef struct rtems_flashdisk
mappings. */
uint32_t block_count; /**< The number of avail. blocks. */
uint32_t unavail_blocks; /**< The number of unavail blocks. */
+ uint32_t starvation_threshold; /**< Erased blocks starvation threshold. */
uint32_t erased_blocks; /**< The number of erased blocks. */
rtems_fdisk_device_ctl* devices; /**< The flash devices for this
@@ -280,7 +281,7 @@ rtems_fdisk_printf (const rtems_flashdisk* fd, const char *format, ...)
static bool
rtems_fdisk_is_erased_blocks_starvation (rtems_flashdisk* fd)
{
- bool starvation = fd->erased_blocks < fd->unavail_blocks;
+ bool starvation = fd->erased_blocks < fd->starvation_threshold;
if (starvation)
fd->starvations++;
@@ -1405,6 +1406,10 @@ rtems_fdisk_compact (rtems_flashdisk* fd)
if (rtems_fdisk_is_erased_blocks_starvation (fd))
{
+#if RTEMS_FDISK_TRACE
+ rtems_fdisk_printf (fd, " resolve starvation");
+#endif
+
ssc = rtems_fdisk_segment_queue_pop_head (&fd->used);
if (!ssc)
ssc = rtems_fdisk_segment_queue_pop_head (&fd->available);
@@ -1482,7 +1487,12 @@ rtems_fdisk_compact (rtems_flashdisk* fd)
*/
if (!ssc || (pages == 0) || ((compacted_segs + segments) == 1))
+ {
+#if RTEMS_FDISK_TRACE
+ rtems_fdisk_printf (fd, " nothing to compact");
+#endif
break;
+ }
#if RTEMS_FDISK_TRACE
rtems_fdisk_printf (fd, " ssc scan: %d-%d: p=%ld, seg=%ld",
@@ -1539,6 +1549,7 @@ rtems_fdisk_recover_block_mappings (rtems_flashdisk* fd)
* Scan each segment or each device recovering the valid pages.
*/
fd->erased_blocks = 0;
+ fd->starvation_threshold = 0;
for (device = 0; device < fd->device_count; device++)
{
uint32_t segment;
@@ -1557,6 +1568,8 @@ rtems_fdisk_recover_block_mappings (rtems_flashdisk* fd)
sc->pages_desc = rtems_fdisk_page_desc_pages (sd, fd->block_size);
sc->pages =
rtems_fdisk_pages_in_segment (sd, fd->block_size) - sc->pages_desc;
+ if (sc->pages > fd->starvation_threshold)
+ fd->starvation_threshold = sc->pages;
sc->pages_active = 0;
sc->pages_used = 0;
@@ -2225,6 +2238,7 @@ rtems_fdisk_print_status (rtems_flashdisk* fd)
rtems_fdisk_printf (fd, "Block count\t%d", fd->block_count);
rtems_fdisk_printf (fd, "Unavail blocks\t%d", fd->unavail_blocks);
+ rtems_fdisk_printf (fd, "Starvation threshold\t%d", fd->starvation_threshold);
rtems_fdisk_printf (fd, "Starvations\t%d", fd->starvations);
count = rtems_fdisk_segment_count_queue (&fd->available);
total = count;