/* * linux/mm/msync.c * * Copyright (C) 1994-1999 Linus Torvalds */ /* * The msync() system call. */ #include #include #include #include #include #include /* * MS_SYNC syncs the entire file - including mappings. * * MS_ASYNC does not start I/O (it used to, up to 2.5.67). * Nor does it marks the relevant pages dirty (it used to up to 2.6.17). * Now it doesn't do anything, since dirty pages are properly tracked. * * The application may now run fsync() to * write out the dirty pages and wait on the writeout and check the result. * Or the application may run fadvise(FADV_DONTNEED) against the fd to start * async writeout immediately. * So by _not_ starting I/O in MS_ASYNC we provide complete flexibility to * applications. */ SYSCALL_DEFINE3(msync, unsigned long, start, size_t, len, int, flags) { unsigned long end; struct mm_struct *mm = current->mm; struct vm_area_struct *vma; int unmapped_error = 0; int error = -EINVAL; if (flags & ~(MS_ASYNC | MS_INVALIDATE | MS_SYNC)) goto out; if (offset_in_page(start)) goto out; if ((flags & MS_ASYNC) && (flags & MS_SYNC)) goto out; error = -ENOMEM; len = (len + ~PAGE_MASK) & PAGE_MASK; end = start + len; if (end < start) goto out; error = 0; if (end == start) goto out; /* * If the interval [start,end) covers some unmapped address ranges, * just ignore them, but return -ENOMEM at the end. */ down_read(&mm->mmap_sem); vma = find_vma(mm, start); for (;;) { struct file *file; loff_t fstart, fend; /* Still start < end. */ error = -ENOMEM; if (!vma) goto out_unlock; /* Here start < vma->vm_end. */ if (start < vma->vm_start) { start = vma->vm_start; if (start >= end) goto out_unlock; unmapped_error = -ENOMEM; } /* Here vma->vm_start <= start < vma->vm_end. */ if ((flags & MS_INVALIDATE) && (vma->vm_flags & VM_LOCKED)) { error = -EBUSY; goto out_unlock; } file = vma->vm_file; fstart = (start - vma->vm_start) + ((loff_t)vma->vm_pgoff << PAGE_SHIFT); fend = fstart + (min(end, vma->vm_end) - start) - 1; start = vma->vm_end; if ((flags & MS_SYNC) && file && (vma->vm_flags & VM_SHARED)) { get_file(file); up_read(&mm->mmap_sem); error = vfs_fsync_range(file, fstart, fend, 1); fput(file); if (error || start >= end) goto out; down_read(&mm->mmap_sem); vma = find_vma(mm, start); } else { if (start >= end) { error = 0; goto out_unlock; } vma = vma->vm_next; } } out_unlock: up_read(&mm->mmap_sem); out: return error ? : unmapped_error; } earch'/>
path: root/include/scsi/libiscsi_tcp.h
diff options
context:
space:
mode:
authorSteven Rostedt (VMware) <rostedt@goodmis.org>2017-01-30 19:27:10 -0500
committerSteven Rostedt (VMware) <rostedt@goodmis.org>2017-01-31 09:13:49 -0500
commit79c6f448c8b79c321e4a1f31f98194e4f6b6cae7 (patch)
tree370efda701f03cccf21e02bb1fdd3b852547d75c /include/scsi/libiscsi_tcp.h
parent0c744ea4f77d72b3dcebb7a8f2684633ec79be88 (diff)
tracing: Fix hwlat kthread migration
The hwlat tracer creates a kernel thread at start of the tracer. It is pinned to a single CPU and will move to the next CPU after each period of running. If the user modifies the migration thread's affinity, it will not change after that happens. The original code created the thread at the first instance it was called, but later was changed to destroy the thread after the tracer was finished, and would not be created until the next instance of the tracer was established. The code that initialized the affinity was only called on the initial instantiation of the tracer. After that, it was not initialized, and the previous affinity did not match the current newly created one, making it appear that the user modified the thread's affinity when it did not, and the thread failed to migrate again. Cc: stable@vger.kernel.org Fixes: 0330f7aa8ee6 ("tracing: Have hwlat trace migrate across tracing_cpumask CPUs") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'include/scsi/libiscsi_tcp.h')