len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj); return simple_read_from_buffer(buf, count, ppos, buffer, len); } /proc/xxx/oom_score:只读。经过oom_badness()计算得出对当前进程消耗页面数目,然后相对于totalpages归一化到1000。 static int proc_oom_score(struct seq_file *m, stru...
*buffer, size_t length, loff_t *offset) { u32 data; if (copy_from_user(&data, buffer, sizeof(data))) { return -EFAULT; } iowrite32(data, mem_map + *offset); *offset += sizeof(data); return sizeof(data); } static struct file_operations fops = { .read = device_read, ....
h> /** * This is a simple example for using open(), write(), read(), lseek() and close(). */ int main(int argc, char *argv[]) { int fd; ssize_t wr_size, rd_size; char buffer[128]; char string_1[30], string_2[30] = "This is the second line!\n"; char *path =...
ctrl-l/u, alt-cClear the kernel ring buffer [d], alt-dShow the dependent modules [1]..[9]Jump to the dependent module [\], tab, backtabShow the next kernel information [/], s, enterSearch a kernel module [+], i, insertLoad a kernel module ...
(copy_from_user(example_buffer, buf, count)) return -EFAULT; return count; } static ssize_t test_proc_read(struct file *file, char __user *buf, size_t size, loff_t *ppos) { return simple_read_from_buffer(buf, size, ppos, example_buffer, strlen(example_buffer)); } static const ...
字符设备与块设备是并列的概念,这两类设备在Linux中的驱动结构差异较大,总体而言,块设备驱动比字符设备驱动要复杂的多,在I/O操作上也表现出极大的不同。缓冲,I/O调度、请求队列等都是与块设备驱动相关的概念。 2.块设备I/O操作特点 字符设备与块设备I/O操作的不同如下: ...
0x61b7b126 simple_strtoull vmlinux EXPORT_SYMBOL 0x528c709d simple_read_from_buffer vmlinux EXPORT_SYMBOL 0xe83e74d0 class_device_destroy vmlinux EXPORT_SYMBOL_GPL 0xa681fe88 generate_random_uuid vmlinux EXPORT_SYMBOL 0x196f57d2 vfs_statfs vmlinux EXPORT_SYMBOL 0x6b37068c udp_ioctl...
read into this file. Change this folder according to your server #pos_file PATH /home/user1/fluent-test/demo_simple_match.log.pos # tag is used to correlate the directives. For example, source with corresponding filter and match directives. tag scom.log #reads the fields from the log ...
6、DMA:负责把 dma buffer 中的音频数据搬运到 I2S tx FIFO。 五、调试命令 ALSA是Linux处理音频的基本接口,但ALSA只提供基层的接口,操作较为繁复,一般情况下可以直接使用其附带提供的 utils 工具集,utils 工具集是一些封装好了的功能模块,直接以命令的方式提供,用户只需要敲入相关命令和参数即可实现音频操作功能。
lib: make sprint_canframe the buffer size aware snprintf_canframe Mar 13, 2024 page.theme import sample program & help page Nov 20, 2013 slcan_attach.c slcan: increase BTR char limit to 8 for 32bit BTR Feb 23, 2023 slcand.c