深入理解Linux内核共享内存机制- shmem&tmpfs 搞过Linux人都知道,Linux的世界中,进程的虚拟地址空间有两部分组成:内核空间和用户空间,内核空间各个进程直接共享,而用户空间彼此隔离,大家井水不犯河水。但是并不是老死不相往来,我们有时候需要进程直接共享一些数据,于是乎,Linux就有了共享内存的机制。 我们在使用Linux时...
(struct vfsmount *mnt, const char *name, loff_t size, unsigned long flags) shmem_kernel_file_setup(const char *name, loff_t size, unsigned long flags) shmem_read_mapping_page_gfp(struct address_space *mapping, pgoff_t index, gfp_t gfp) shmem_zero_setup(struct vm_area_struct *vma)...
struct file *shmem_file_setup_with_mnt(struct vfsmount *mnt, const char *name,loff_t size, unsigned long flags){return __shmem_file_setup(mnt, name, size, flags, 0);}EXPORT_SYMBOL_GPL(shmem_file_setup_with_mnt);/*** shmem_zero_setup - setup a shared anonymous mapping...
wait count can be incremented only if the SmcvUnusable flag is off in the lockword flag field. If this flag is on, the condition variable has been destroyed and is no longer usable. On a pthread_cond_signal, if the wait count is found to be zero, no call to the...
(shmem_file_setup); /** * shmem_zero_setup - setup a shared anonymous mapping * @vma: the vma to be mmapped is prepared by do_mmap_pgoff */ int shmem_zero_setup(struct vm_area_struct *vma) { struct file *file; loff_t size = vma->vm_end - vma->vm_start; /* * Cloning a...
// Zero out the first two words (ncmd and nsig), so that we don't have garbage there // if executor crashes before writing non-garbage there. for i := 0; i < 4; i++ { @@ -265,7 +257,7 @@ func (env *Env) ExecProg(opts *flatrpc.ExecOpts, progData []byte) ( } star...
这个时候会发生缺页异常,page cache查询不到物理页面PAGE1,会申请物理页面并加入文件实例对应的page cache,并通过页表映射PAGE1到send进程的虚拟地址空间。 缺页返回后,将数据写入PAGE1(这里都是'a')。 5)recv进程首次读访问数据 同样也会发生缺页异常,但是会首先查询page cache,发现PAGE1,然后通过页表映射PAGE1到...
wait count can be incremented only if the SmcvUnusable flag is off in the lockword flag field. If this flag is on, the condition variable has been destroyed and is no longer usable. On a pthread_cond_signal, if the wait count is found to be zero, no call to the...
这个时候会发生缺页异常,page cache查询不到物理页面PAGE1,会申请物理页面并加入文件实例对应的page cache,并通过页表映射PAGE1到send进程的虚拟地址空间。 缺页返回后,将数据写入PAGE1(这里都是'a')。 5)recv进程首次读访问数据 同样也会发生缺页异常,但是会首先查询page cache,发现PAGE1,然后通过页表映射PAGE1到...
ZeroEnum common sub_init_loop CMakeLists.txt DCPS_IDL_tests.mwc_skip README FACE Utils cmake dissector googletest security stress-tests transport unit-tests CMakeLists.txt auto_run_tests.pl core_ci_tests.lst dcps_tests.lst gtest_setup.txt tsan_tests.lst ubsan_tests.lst valgrind_tests.lst ...