Hi,
I am using sample project (with the name of LittleFS) and am using nRF52840 dev kit. I modified the project to run a loop of 100 iteration. In the loop I am writing 1KB array in separate file on external flash (mx25r64). Most of the the time the process of opening, writing 1KB data and closing the file takes around 100 to 150ms. But sometimes one of the step (out of opening, writing or closing file) gets stuck for upto 13 seconds. Which is considerably longer than the average.
Has anyone else experienced anything like that? What should I do to eliminate the random SLOW IOs
the function that writes the file (and is called in a loop from main()) does things like:
int64_t s2 = k_uptime_get();
rc = fs_open(&file, fname, FS_O_CREATE | FS_O_WRITE);
int64_t s3 = k_uptime_get();
rc = fs_seek(&file, 0, FS_SEEK_SET);
int64_t s4 = k_uptime_get();
rc = fs_write(&file, data, len);
int64_t s5 = k_uptime_get();
fs_close(&file);
int64_t s6 = k_uptime_get();
int64_t res1 = s2 - s1;
int64_t res2 = s3 - s2;
int64_t res3 = s4 - s3;
int64_t res4 = s5 - s4;
int64_t res5 = s6 - s5;
int64_t res_all = (res1 + res2 + res3 + res4 + res5);
/**
* @brief Print them out
*
*/
printk("init = %lld, open = %lld, seek = %lld, write = %lld, close = %lld, \t\t total = %lld\n", res1, res2, res3, res4, res5, res_all);
The overlay file is:
The prj.conf are:
/delete-node/ &storage_partition;
/ {
fstab {
compatible = "zephyr,fstab";
lfs1: lfs1 {
compatible = "zephyr,fstab,littlefs";
mount-point = "/lfs1";
partition = <&lfs1_part>;
automount;
read-size = <64>;
prog-size = <64>;
cache-size = <256>;
lookahead-size = <128>;
block-cycles = <512>;
};
};
};
&mx25r64 {
partitions {
compatible = "fixed-partitions";
#address-cells = <1>;
#size-cells = <1>;
lfs1_part: partition@0 {
label = "storage";
reg = <0x0 0x800000>;
};
};
};
/ {
chosen {
nordic,pm-ext-flash = &mx25r64;
};
};
The prj.conf are:
CONFIG_MAIN_STACK_SIZE=40960
# Let __ASSERT do its job
CONFIG_DEBUG=y
CONFIG_LOG=y
CONFIG_FLASH=y
CONFIG_FLASH_MAP=y
CONFIG_FLASH_PAGE_LAYOUT=y
CONFIG_FILE_SYSTEM=y
CONFIG_FILE_SYSTEM_LITTLEFS=y
CONFIG_APP_WIPE_STORAGE=n
CONFIG_LOG_BUFFER_SIZE=60240
