Linux Kernel Architecture

Chapter 2: Process Management and Scheduling At some points in the kernel, the protection by the normal SMP synchronization meth ...

Chapter 2: Process Management and Scheduling The following steps are required if preemption is possible: kernel/sched.c do { add ...

Chapter 2: Process Management and Scheduling This method is only one way of triggering kernel preemption. Another possibility to ...

Chapter 2: Process Management and Scheduling If a large number of read operations is required, this can consume a sizeable amoun ...

Memory Management Memory management is one of the most complex and at the same time most important parts of the kernel. It is ch ...

Chapter 3: Memory Management Chapter 3: Memory Management............................................ allocations in the kernel ...

Chapter3:MemoryManagement Figure 3-1 illustrates the difference between the two approaches. Memory CPU 0 CPU 1 CPU 3 Memory CPU ...

Chapter3:MemoryManagement Sparse memory NUMA UMA Discontiguous Flat memory memory NUMA UMA Address space without holes Figure 3- ...

Chapter3:MemoryManagement pg_data_t ZONELIST Z O N E S pg_data_t ZONELIST Z O N E S pg_data_t ZONELIST Z O N E S Page Tables Fig ...

Chapter3:MemoryManagement Depending on the compile-time configuration, some zones need not be considered. 64-bit systems, for in ...

Chapter3:MemoryManagement ❑ node_zonesis an array that holds the data structures of the zones in the node. ❑ node_zonelistsspeci ...

Chapter3:MemoryManagement N_HIGH_MEMORY, /* The node has regular or high memory */ #else N_HIGH_MEMORY = N_NORMAL_MEMORY, #endif ...

Chapter3:MemoryManagement unsigned long flags; /* zone flags, see below */ /* Zone statistics */ atomic_long_t vm_stat[NR_VM_ZON ...

Chapter3:MemoryManagement ❑ pages_min,pages_high,andpages_loware ‘‘watermarks‘‘used when pages are swapped out. The kernel can w ...

Chapter3:MemoryManagement ZONE_OOM_LOCKED, /* zone is in OOM killer zonelist */ } zone_flags_t; It is also possible that none of ...

Chapter3:MemoryManagement ❑ wait_table,wait_table_bits,andwait_table_hash_nr_entriesimplement a wait queue for processes waiting ...

Chapter3:MemoryManagement ... for_each_zone(zone) { u64 tmp; tmp = (u64)pages_min * zone->present_pages; do_div(tmp,lowmem_pa ...

Chapter3:MemoryManagement Table 3-1: Correlation between Main Memory Size and Minimum Memory Available for Critical Allocations. ...

Chapter3:MemoryManagement it were in RAM. Conversely, acoldpage is not held in cache. As each CPU has one or more caches on mult ...

Chapter3:MemoryManagement Whereascountkeeps a record of the number of pages associated with the element,highis a watermark. If t ...