dark0707
/
px4-firmware
forked from Archive/PX4-Autopilot
1
0
Fork 0
Code Pull Requests Activity

Reduce potential dataman memory fragmentation 

The data manager dynamically allocates relatively small work item blocks
on an as needed basis. It never frees these, instead maintaining then in
a list of available block for reuse when needed. Even if these blocks
are small, the are required at non-deterministic times and can end up
scattered in memory thus causing memory fragmentation. In order to
mitigate this problems work item blocks are allocated in groups of 8 in
contiguous memory to reduce the number of scattered memory allocations.
In reality, based on current usage, rarely will more than one group of 8
be allocated.
This commit is contained in:
Jean Cyr 2014-05-13 19:59:44 -04:00
parent 178a3e8567
commit 8d3fed0944
1 changed files with 16 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
src/modules/dataman/dataman.c
View File

@ -100,6 +100,8 @@ typedef struct {
};
} work_q_item_t;
const size_t k_work_item_allocation_chunk_size = 8;
/* Usage statistics */
static unsigned g_func_counts[dm_number_of_funcs];
@ -177,9 +179,20 @@ create_work_item(void)
unlock_queue(&g_free_q);
/* If we there weren't any free items then obtain memory for a new one */
if (item == NULL)
item = (work_q_item_t *)malloc(sizeof(work_q_item_t));
/* If we there weren't any free items then obtain memory for a new ones */
if (item == NULL) {
item = (work_q_item_t *)malloc(k_work_item_allocation_chunk_size * sizeof(work_q_item_t));
if (item) {
lock_queue(&g_free_q);
for (int i = 1; i < k_work_item_allocation_chunk_size; i++)
sq_addfirst(&(item + i)->link, &(g_free_q.q));
/* Update the queue size and potentially the maximum queue size */
g_free_q.size += k_work_item_allocation_chunk_size - 1;
if (g_free_q.size > g_free_q.max_size)
g_free_q.max_size = g_free_q.size;
unlock_queue(&g_free_q);
}
}
/* If we got one then lock the item*/
if (item)