On linux, there are commands for almost everything, because the gui might not be always available. When working on servers only shell access is available and everything has to be done from these commands. So today we shall be checking the commands that can be used to check memory usage on...
Check Linux memory usage with the free command To check available free memory and swaps, use thefreecommand. Just run the command like bellow, no root privilege required. free -h It's worth to pass few more command line arguments to get more convenient results. ...
[root@my-host mg4a]# grep kernel /var/log/messagesJan 14 19:01:11 my-host kernel: mce: [Hardware Error]: Machine check events loggedJan 14 19:01:12 my-host kernel: EDAC MC0: 1 CE memoryreaderror on CPU_SrcID#0_Ha#1_Chan#1_DIMM#0 (channel:5 slot:0 page:0x554c02 offset:0x3...
即可以传输到设备也可以从设备传出,返回物理地址 scratch_addr = dma_map_single(..., DMA_BIDIRECTIONAL); dwc->scratch_addr = scratch_addr // 保存物理地址 param = lower_32_bits(scratch_addr) // 获取低32位物理地址 dwc3_send_gadget_generic_command(..., DWC3_DGCMD_SET_SCRATCHPAD_ADDR_LO,...
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 22804 root 20 0 108096 616 516 R 99.7 0.0 1:05.71 dd 可以看到该 dd 进程消耗了 99.7% 的 CPU。备注 可以通过选择 1 在top工具中显示每 CPU 使用率。 如果进程是多线程的,并且跨越多个 CPU,该工具 top 将显示总使用率超过 100%。另...
CMA区域的创建有两种方法,一种是通过dts的reserved memory,另外一种是通过command line参数和内核配置参数。 dts方式: reserved-memory { /* global autoconfigured region for contiguous allocations */ linux,cma { compatible = "shared-dma-pool";
MEMORY: 崩溃主机的物理内存 PANIC: 崩溃类型,常见的崩溃类型包括: SysRq (System Request):通过魔法组合键导致的系统崩溃,通常是测试使用。通过 echo c > /proc/sysrq-trigger,就可以触发系统崩溃。 oops:可以看成是内核级的 Segmentation Fault。应用程序如果进行了非法内存访问或执行了非法指令,会得到 Segfault ...
command line方式:cma=nn[MG]@[start[MG][-end[MG]]] static int __init early_cma(char *p){ pr_debug("%s(%s)\n", __func__, p); size_cmdline = memparse(p, &p); if (*p != '@') { /* if base and limit are not assigned, set limit to high memory bondary to use low memo...
which [-a] COMMAND -a:列出所有COMMAND命令。 文件内容查看 cat 正向显示全部内容。 cat [-AbEnTv] FILENAME[ ...]|STDIN -A:相当于-vET。 -b:显示行号,仅针对非空白行。 -E:将换行符显示为$。 -n:显示行号,包括空白行。 -T:将Tab显示为^I。
非一致性内存访问 NUMA(Non-Uniform Memory Access)意思是内存被划分为各个node,访问一个node花费的时间取决于CPU离这个node的距离。每一个cpu内部有一个本地的node,访问本地node时间比访问其他node的速度快 一致性内存访问 UMA(Uniform Memory Access)也可以称为SMP(Symmetric Multi-Process)对称多处理器。意思是所有...