#include #include #include #include #include #include #include #include #include #include "xenfs.h" #define XEN_KSYM_NAME_LEN 127 /* Hypervisor may have different name length */ struct xensyms { struct xen_platform_op op; char *name; uint32_t namelen; }; /* Grab next output page from the hypervisor */ static int xensyms_next_sym(struct xensyms *xs) { int ret; struct xenpf_symdata *symdata = &xs->op.u.symdata; uint64_t symnum; memset(xs->name, 0, xs->namelen); symdata->namelen = xs->namelen; symnum = symdata->symnum; ret = HYPERVISOR_platform_op(&xs->op); if (ret < 0) return ret; /* * If hypervisor's symbol didn't fit into the buffer then allocate * a larger buffer and try again. */ if (unlikely(symdata->namelen > xs->namelen)) { kfree(xs->name); xs->namelen = symdata->namelen; xs->name = kzalloc(xs->namelen, GFP_KERNEL); if (!xs->name) return -ENOMEM; set_xen_guest_handle(symdata->name, xs->name); symdata->symnum--; /* Rewind */ ret = HYPERVISOR_platform_op(&xs->op); if (ret < 0) return ret; } if (symdata->symnum == symnum) /* End of symbols */ return 1; return 0; } static void *xensyms_start(struct seq_file *m, loff_t *pos) { struct xensyms *xs = (struct xensyms *)m->private; xs->op.u.symdata.symnum = *pos; if (xensyms_next_sym(xs)) return NULL; return m->private; } static void *xensyms_next(struct seq_file *m, void *p, loff_t *pos) { struct xensyms *xs = (struct xensyms *)m->private; xs->op.u.symdata.symnum = ++(*pos); if (xensyms_next_sym(xs)) return NULL; return p; } static int xensyms_show(struct seq_file *m, void *p) { struct xensyms *xs = (struct xensyms *)m->private; struct xenpf_symdata *symdata = &xs->op.u.symdata; seq_printf(m, "%016llx %c %s\n", symdata->address, symdata->type, xs->name); return 0; } static void xensyms_stop(struct seq_file *m, void *p) { } static const struct seq_operations xensyms_seq_ops = { .start = xensyms_start, .next = xensyms_next, .show = xensyms_show, .stop = xensyms_stop, }; static int xensyms_open(struct inode *inode, struct file *file) { struct seq_file *m; struct xensyms *xs; int ret; ret = seq_open_private(file, &xensyms_seq_ops, sizeof(struct xensyms)); if (ret) return ret; m = file->private_data; xs = (struct xensyms *)m->private; xs->namelen = XEN_KSYM_NAME_LEN + 1; xs->name = kzalloc(xs->namelen, GFP_KERNEL); if (!xs->name) { seq_release_private(inode, file); return -ENOMEM; } set_xen_guest_handle(xs->op.u.symdata.name, xs->name); xs->op.cmd = XENPF_get_symbol; xs->op.u.symdata.namelen = xs->namelen; return 0; } static int xensyms_release(struct inode *inode, struct file *file) { struct seq_file *m = file->private_data; struct xensyms *xs = (struct xensyms *)m->private; kfree(xs->name); return seq_release_private(inode, file); } const struct file_operations xensyms_ops = { .open = xensyms_open, .read = seq_read, .llseek = seq_lseek, .release = xensyms_release }; -remove&id=79c6f448c8b79c321e4a1f31f98194e4f6b6cae7'>soc/davinci
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 /sound/soc/davinci
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 'sound/soc/davinci')