On 1/17/19 7:52 AM, tien.fong.chee@intel.com wrote:
From: Stefan Agner stefan.ag...@toradex.com
Drop the statically allocated get_contents_vfatname_block and dynamically allocate a buffer only if required. This saves 64KiB of memory.
Signed-off-by: Stefan Agner stefan.ag...@toradex.com Signed-off-by: Tien Fong Chee tien.fong.chee@intel.com
fs/fat/fat.c | 19 +++++++++++++------ 1 files changed, 13 insertions(+), 6 deletions(-)
diff --git a/fs/fat/fat.c b/fs/fat/fat.c index 8803fb4..aa4636d 100644 --- a/fs/fat/fat.c +++ b/fs/fat/fat.c @@ -307,9 +307,6 @@ get_cluster(fsdata *mydata, __u32 clustnum, __u8 *buffer, unsigned long size)
- into 'buffer'.
- Update the number of bytes read in *gotsize or return -1 on fatal errors.
*/ -__u8 get_contents_vfatname_block[MAX_CLUSTSIZE]
- __aligned(ARCH_DMA_MINALIGN);
static int get_contents(fsdata *mydata, dir_entry *dentptr, loff_t pos, __u8 *buffer, loff_t maxsize, loff_t *gotsize) { @@ -320,7 +317,7 @@ static int get_contents(fsdata *mydata, dir_entry *dentptr, loff_t pos, loff_t actsize;
*gotsize = 0;
- debug("Filesize: %llu bytes\n", filesize);
- debug("Filesize: %llu bytes, starting at pos %llu\n", filesize, pos);
This looks like a separate change.
if (pos >= filesize) { debug("Read position past EOF: %llu\n", pos); @@ -352,15 +349,25 @@ static int get_contents(fsdata *mydata, dir_entry *dentptr, loff_t pos,
/* align to beginning of next cluster if any */ if (pos) {
__u8 *tmp_buffer;tmp_buffer = malloc_cache_aligned(MAX_CLUSTSIZE);
Don't you know the cluster size by now ?
if (!tmp_buffer) {debug("Error: allocating buffer\n");return -ENOMEM;}- actsize = min(filesize, (loff_t)bytesperclust);
if (get_cluster(mydata, curclust, get_contents_vfatname_block,
if (get_cluster(mydata, curclust, tmp_buffer, (int)actsize) != 0) { printf("Error reading cluster\n");free(tmp_buffer); return -1;
memcpy(buffer, get_contents_vfatname_block + pos, actsize);
memcpy(buffer, tmp_buffer + pos, actsize);free(tmp_buffer);
How many times is this malloc()/free() called ? I wonder how much this slows things down and how much it fragments the heap. Maybe the amount of calls to this can be reduced somehow.
*gotsize += actsize; if (!filesize) return 0;