1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
2 * vim:expandtab:shiftwidth=8:tabstop=8:
4 * Copyright (C) 2003 Cluster File Systems, Inc.
5 * Author: Eric Barton <eeb@clusterfs.com>
7 * This file is part of Lustre, http://www.lustre.org.
9 * Lustre is free software; you can redistribute it and/or
10 * modify it under the terms of version 2 of the GNU General Public
11 * License as published by the Free Software Foundation.
13 * Lustre is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with Lustre; if not, write to the Free Software
20 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25 #include <linux/config.h>
26 #include <linux/module.h>
27 #include <linux/kmod.h>
28 #include <linux/kernel.h>
29 #include <linux/kernel.h>
31 #include <linux/string.h>
32 #include <linux/stat.h>
33 #include <linux/errno.h>
34 #include <linux/smp_lock.h>
35 #include <linux/unistd.h>
36 #include <linux/interrupt.h>
37 #include <asm/system.h>
38 #include <asm/uaccess.h>
40 #define DEBUG_SUBSYSTEM S_PORTALS
42 #include <linux/kp30.h>
46 #define LWT_MEMORY (1<<20) /* 1Mb of trace memory */
47 #define LWT_MAX_CPUS 4
50 int lwt_pages_per_cpu;
51 lwt_cpu_t lwt_cpus[LWT_MAX_CPUS];
53 /* NB only root is allowed to retrieve LWT info; it's an open door into the
57 lwt_lookup_string (int *size, char *knl_ptr,
58 char *user_ptr, int user_size)
60 /* knl_ptr was retrieved from an LWT snapshot and the caller wants to
61 * turn it into a string. NB we can crash with an access violation
62 * trying to determine the string length, so we're trusting our
65 if (!capable(CAP_SYS_ADMIN))
68 *size = strlen (knl_ptr) + 1;
70 if (user_ptr != NULL &&
71 copy_to_user (user_ptr, knl_ptr, *size))
78 lwt_control (int enable, int clear)
84 if (!capable(CAP_SYS_ADMIN))
88 for (i = 0; i < num_online_cpus(); i++) {
89 p = lwt_cpus[i].lwtc_current_page;
91 for (j = 0; j < lwt_pages_per_cpu; j++) {
93 memset (p->lwtp_events, 0, PAGE_SIZE);
95 p = list_entry (p->lwtp_list.next,
96 lwt_page_t, lwtp_list);
100 lwt_enabled = enable;
103 /* give people some time to stop adding traces */
104 schedule_timeout(10);
111 lwt_snapshot (int *ncpu, int *total_size,
112 void *user_ptr, int user_size)
114 const int events_per_page = PAGE_SIZE / sizeof(lwt_event_t);
115 const int bytes_per_page = events_per_page * sizeof(lwt_event_t);
120 if (!capable(CAP_SYS_ADMIN))
123 *ncpu = num_online_cpus();
124 *total_size = num_online_cpus() * lwt_pages_per_cpu * bytes_per_page;
126 if (user_ptr == NULL)
129 for (i = 0; i < num_online_cpus(); i++) {
130 p = lwt_cpus[i].lwtc_current_page;
132 for (j = 0; j < lwt_pages_per_cpu; j++) {
133 if (copy_to_user(user_ptr, p->lwtp_events,
137 user_ptr = ((char *)user_ptr) + bytes_per_page;
138 p = list_entry(p->lwtp_list.next,
139 lwt_page_t, lwtp_list);
153 if (num_online_cpus() > LWT_MAX_CPUS) {
154 CERROR ("Too many CPUs\n");
158 /* NULL pointers, zero scalars */
159 memset (lwt_cpus, 0, sizeof (lwt_cpus));
160 lwt_pages_per_cpu = LWT_MEMORY / (num_online_cpus() * PAGE_SIZE);
162 for (i = 0; i < num_online_cpus(); i++)
163 for (j = 0; j < lwt_pages_per_cpu; j++) {
164 struct page *page = alloc_page (GFP_KERNEL);
168 CERROR ("Can't allocate page\n");
173 PORTAL_ALLOC(lwtp, sizeof (*lwtp));
175 CERROR ("Can't allocate lwtp\n");
181 lwtp->lwtp_page = page;
182 lwtp->lwtp_events = page_address(page);
183 memset (lwtp->lwtp_events, 0, PAGE_SIZE);
186 INIT_LIST_HEAD (&lwtp->lwtp_list);
187 lwt_cpus[i].lwtc_current_page = lwtp;
189 list_add (&lwtp->lwtp_list,
190 &lwt_cpus[i].lwtc_current_page->lwtp_list);
205 if (num_online_cpus() > LWT_MAX_CPUS)
208 for (i = 0; i < num_online_cpus(); i++)
209 while (lwt_cpus[i].lwtc_current_page != NULL) {
210 lwt_page_t *lwtp = lwt_cpus[i].lwtc_current_page;
212 if (list_empty (&lwtp->lwtp_list)) {
213 lwt_cpus[i].lwtc_current_page = NULL;
215 lwt_cpus[i].lwtc_current_page =
216 list_entry (lwtp->lwtp_list.next,
217 lwt_page_t, lwtp_list);
219 list_del (&lwtp->lwtp_list);
222 __free_page (lwtp->lwtp_page);
223 PORTAL_FREE (lwtp, sizeof (*lwtp));
227 EXPORT_SYMBOL(lwt_enabled);
228 EXPORT_SYMBOL(lwt_cpus);
230 EXPORT_SYMBOL(lwt_init);
231 EXPORT_SYMBOL(lwt_fini);
232 EXPORT_SYMBOL(lwt_lookup_string);
233 EXPORT_SYMBOL(lwt_control);
234 EXPORT_SYMBOL(lwt_snapshot);