+++ /dev/null
-/*
- * GPL HEADER START
- *
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 only,
- * as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License version 2 for more details (a copy is included
- * in the LICENSE file that accompanied this code).
- *
- * You should have received a copy of the GNU General Public License
- * version 2 along with this program; If not, see
- * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
- *
- * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
- * CA 95054 USA or visit www.sun.com if you need additional information or
- * have any questions.
- *
- * GPL HEADER END
- */
-/*
- * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
- * Use is subject to license terms.
- */
-/*
- * This file is part of Lustre, http://www.lustre.org/
- * Lustre is a trademark of Sun Microsystems, Inc.
- *
- * libcfs/libcfs/lwt.c
- *
- * Author: Eric Barton <eeb@clusterfs.com>
- */
-
-#define DEBUG_SUBSYSTEM S_LNET
-
-#include <libcfs/libcfs.h>
-
-#if LWT_SUPPORT
-
-#if !KLWT_SUPPORT
-int lwt_enabled;
-lwt_cpu_t lwt_cpus[CFS_NR_CPUS];
-#endif
-
-int lwt_pages_per_cpu;
-
-/* NB only root is allowed to retrieve LWT info; it's an open door into the
- * kernel... */
-
-int
-lwt_lookup_string (int *size, char *knl_ptr,
- char *user_ptr, int user_size)
-{
- int maxsize = 128;
-
- /* knl_ptr was retrieved from an LWT snapshot and the caller wants to
- * turn it into a string. NB we can crash with an access violation
- * trying to determine the string length, so we're trusting our
- * caller... */
-
- if (!cfs_capable(CFS_CAP_SYS_ADMIN))
- return (-EPERM);
-
- if (user_size > 0 &&
- maxsize > user_size)
- maxsize = user_size;
-
- *size = strnlen (knl_ptr, maxsize - 1) + 1;
-
- if (user_ptr != NULL) {
- if (user_size < 4)
- return -EINVAL;
-
- if (copy_to_user(user_ptr, knl_ptr, *size))
- return -EFAULT;
-
- /* Did I truncate the string? */
- if (knl_ptr[*size - 1] != 0)
- copy_to_user(user_ptr + *size - 4, "...", 4);
- }
-
- return 0;
-}
-
-int
-lwt_control (int enable, int clear)
-{
- lwt_page_t *p;
- int i;
- int j;
-
- if (!cfs_capable(CFS_CAP_SYS_ADMIN))
- return (-EPERM);
-
- if (!enable) {
- LWT_EVENT(0,0,0,0);
- lwt_enabled = 0;
- cfs_mb();
- /* give people some time to stop adding traces */
- cfs_schedule_timeout(10);
- }
-
- for (i = 0; i < cfs_num_online_cpus(); i++) {
- p = lwt_cpus[i].lwtc_current_page;
-
- if (p == NULL)
- return (-ENODATA);
-
- if (!clear)
- continue;
-
- for (j = 0; j < lwt_pages_per_cpu; j++) {
- memset(p->lwtp_events, 0, PAGE_CACHE_SIZE);
-
- p = cfs_list_entry (p->lwtp_list.next,
- lwt_page_t, lwtp_list);
- }
- }
-
- if (enable) {
- lwt_enabled = 1;
- cfs_mb();
- LWT_EVENT(0,0,0,0);
- }
-
- return (0);
-}
-
-int
-lwt_snapshot(cfs_cycles_t *now, int *ncpu, int *total_size,
- void *user_ptr, int user_size)
-{
- const int events_per_page = PAGE_CACHE_SIZE / sizeof(lwt_event_t);
- const int bytes_per_page = events_per_page * sizeof(lwt_event_t);
- lwt_page_t *p;
- int i;
- int j;
-
- if (!cfs_capable(CFS_CAP_SYS_ADMIN))
- return (-EPERM);
-
- *ncpu = cfs_num_online_cpus();
- *total_size = cfs_num_online_cpus() * lwt_pages_per_cpu *
- bytes_per_page;
- *now = get_cycles();
-
- if (user_ptr == NULL)
- return (0);
-
- for (i = 0; i < cfs_num_online_cpus(); i++) {
- p = lwt_cpus[i].lwtc_current_page;
-
- if (p == NULL)
- return -ENODATA;
-
- for (j = 0; j < lwt_pages_per_cpu; j++) {
- if (copy_to_user(user_ptr, p->lwtp_events,
- bytes_per_page))
- return -EFAULT;
-
- user_ptr = ((char *)user_ptr) + bytes_per_page;
- p = cfs_list_entry(p->lwtp_list.next,
- lwt_page_t, lwtp_list);
- }
- }
-
- return (0);
-}
-
-int
-lwt_init ()
-{
- int i;
- int j;
-
- for (i = 0; i < cfs_num_online_cpus(); i++)
- if (lwt_cpus[i].lwtc_current_page != NULL)
- return (-EALREADY);
-
- LASSERT (!lwt_enabled);
-
- /* NULL pointers, zero scalars */
- memset (lwt_cpus, 0, sizeof (lwt_cpus));
- lwt_pages_per_cpu =
- LWT_MEMORY / (cfs_num_online_cpus() * PAGE_CACHE_SIZE);
-
- for (i = 0; i < cfs_num_online_cpus(); i++)
- for (j = 0; j < lwt_pages_per_cpu; j++) {
- struct page *page = alloc_page(GFP_KERNEL);
- lwt_page_t *lwtp;
-
- if (page == NULL) {
- CERROR ("Can't allocate page\n");
- lwt_fini ();
- return (-ENOMEM);
- }
-
- LIBCFS_ALLOC(lwtp, sizeof (*lwtp));
- if (lwtp == NULL) {
- CERROR ("Can't allocate lwtp\n");
- __free_page(page);
- lwt_fini ();
- return (-ENOMEM);
- }
-
- lwtp->lwtp_page = page;
- lwtp->lwtp_events = page_address(page);
- memset(lwtp->lwtp_events, 0, PAGE_CACHE_SIZE);
-
- if (j == 0) {
- CFS_INIT_LIST_HEAD (&lwtp->lwtp_list);
- lwt_cpus[i].lwtc_current_page = lwtp;
- } else {
- cfs_list_add (&lwtp->lwtp_list,
- &lwt_cpus[i].lwtc_current_page->lwtp_list);
- }
- }
-
- lwt_enabled = 1;
- cfs_mb();
-
- LWT_EVENT(0,0,0,0);
-
- return (0);
-}
-
-void
-lwt_fini ()
-{
- int i;
-
- lwt_control(0, 0);
-
- for (i = 0; i < cfs_num_online_cpus(); i++)
- while (lwt_cpus[i].lwtc_current_page != NULL) {
- lwt_page_t *lwtp = lwt_cpus[i].lwtc_current_page;
-
- if (cfs_list_empty (&lwtp->lwtp_list)) {
- lwt_cpus[i].lwtc_current_page = NULL;
- } else {
- lwt_cpus[i].lwtc_current_page =
- cfs_list_entry (lwtp->lwtp_list.next,
- lwt_page_t, lwtp_list);
-
- cfs_list_del (&lwtp->lwtp_list);
- }
-
- __free_page (lwtp->lwtp_page);
- LIBCFS_FREE (lwtp, sizeof (*lwtp));
- }
-}
-
-EXPORT_SYMBOL(lwt_enabled);
-EXPORT_SYMBOL(lwt_cpus);
-
-EXPORT_SYMBOL(lwt_init);
-EXPORT_SYMBOL(lwt_fini);
-EXPORT_SYMBOL(lwt_lookup_string);
-EXPORT_SYMBOL(lwt_control);
-EXPORT_SYMBOL(lwt_snapshot);
-#endif
git://git.whamcloud.com / fs / lustre-release.git / blobdiff