libcfs/libcfs/tracefile.h

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License version 2 for more details (a copy is included
  14  * in the LICENSE file that accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * version 2 along with this program; If not, see
  18  * http://www.gnu.org/licenses/gpl-2.0.html
  19  *
  20  * GPL HEADER END
  21  */
  22 /*
  23  * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Use is subject to license terms.
  25  *
  26  * Copyright (c) 2012, 2017, Intel Corporation.
  27  */
  28 /*
  29  * This file is part of Lustre, http://www.lustre.org/
  30  */
  31
  32 #ifndef __LIBCFS_TRACEFILE_H__
  33 #define __LIBCFS_TRACEFILE_H__
  34
  35 #include <libcfs/libcfs.h>
  36
  37 #define TRACEFILE_NAME_SIZE 1024
  38 extern char      cfs_tracefile[TRACEFILE_NAME_SIZE];
  39 extern long long cfs_tracefile_size;
  40
  41 /**
  42  * The path of debug log dump upcall script.
  43  */
  44 extern char lnet_debug_log_upcall[1024];
  45
  46 int cfs_tracefile_dump_all_pages(char *filename);
  47 void cfs_trace_debug_print(void);
  48 void cfs_trace_flush_pages(void);
  49 int cfs_trace_start_thread(void);
  50 void cfs_trace_stop_thread(void);
  51 int cfs_tracefile_init(int max_pages);
  52 void cfs_tracefile_exit(void);
  53
  54
  55
  56 int cfs_trace_copyout_string(char __user *usr_buffer, int usr_buffer_nob,
  57                              const char *knl_str, char *append);
  58 int cfs_trace_dump_debug_buffer_usrstr(void __user *usr_str, int usr_str_nob);
  59 int cfs_trace_daemon_command(char *str);
  60 int cfs_trace_daemon_command_usrstr(void __user *usr_str, int usr_str_nob);
  61 int cfs_trace_set_debug_mb(int mb);
  62 int cfs_trace_get_debug_mb(void);
  63
  64 extern int  libcfs_panic_in_progress;
  65
  66 #define TCD_MAX_PAGES (5 << (20 - PAGE_SHIFT))
  67 #define TCD_STOCK_PAGES (TCD_MAX_PAGES)
  68 #define CFS_TRACEFILE_SIZE (500 << 20)
  69
  70 union cfs_trace_data_union {
  71         struct cfs_trace_cpu_data {
  72                 /*
  73                  * Even though this structure is meant to be per-CPU, locking
  74                  * is needed because in some places the data may be accessed
  75                  * from other CPUs. This lock is directly used in trace_get_tcd
  76                  * and trace_put_tcd, which are called in libcfs_debug_msg and
  77                  * tcd_for_each_type_lock
  78                  */
  79                 spinlock_t              tcd_lock;
  80                 unsigned long           tcd_lock_flags;
  81
  82                 /*
  83                  * pages with trace records not yet processed by tracefiled.
  84                  */
  85                 struct list_head        tcd_pages;
  86                 /* number of pages on ->tcd_pages */
  87                 unsigned long           tcd_cur_pages;
  88
  89                 /*
  90                  * Maximal number of pages allowed on ->tcd_pages
  91                  * Always TCD_MAX_PAGES * tcd_pages_factor / 100 in current
  92                  * implementation.
  93                  */
  94                 unsigned long           tcd_max_pages;
  95
  96                 /*
  97                  * preallocated pages to write trace records into. Pages from
  98                  * ->tcd_stock_pages are moved to ->tcd_pages by
  99                  * portals_debug_msg().
 100                  *
 101                  * This list is necessary, because on some platforms it's
 102                  * impossible to perform efficient atomic page allocation in a
 103                  * non-blockable context.
 104                  *
 105                  * Such platforms fill ->tcd_stock_pages "on occasion", when
 106                  * tracing code is entered in blockable context.
 107                  *
 108                  * trace_get_tage_try() tries to get a page from
 109                  * ->tcd_stock_pages first and resorts to atomic page
 110                  * allocation only if this queue is empty. ->tcd_stock_pages
 111                  * is replenished when tracing code is entered in blocking
 112                  * context (darwin-tracefile.c:trace_get_tcd()). We try to
 113                  * maintain TCD_STOCK_PAGES (40 by default) pages in this
 114                  * queue. Atomic allocation is only required if more than
 115                  * TCD_STOCK_PAGES pagesful are consumed by trace records all
 116                  * emitted in non-blocking contexts. Which is quite unlikely.
 117                  */
 118                 struct list_head        tcd_stock_pages;
 119                 /* number of pages on ->tcd_stock_pages */
 120                 unsigned long           tcd_cur_stock_pages;
 121
 122                 unsigned short          tcd_shutting_down;
 123                 unsigned short          tcd_cpu;
 124                 unsigned short          tcd_type;
 125                 /* The factors to share debug memory. */
 126                 unsigned short          tcd_pages_factor;
 127         } tcd;
 128         char __pad[L1_CACHE_ALIGN(sizeof(struct cfs_trace_cpu_data))];
 129 };
 130
 131 /* XXX nikita: this declaration is internal to tracefile.c and should probably
 132  * be moved there */
 133 struct page_collection {
 134         struct list_head        pc_pages;
 135 };
 136
 137 /*
 138  * small data-structure for each page owned by tracefiled.
 139  */
 140 /* XXX nikita: this declaration is internal to tracefile.c and should probably
 141  * be moved there */
 142 struct cfs_trace_page {
 143         /*
 144          * page itself
 145          */
 146         struct page             *page;
 147         /*
 148          * linkage into one of the lists in trace_data_union or
 149          * page_collection
 150          */
 151         struct list_head        linkage;
 152         /*
 153          * number of bytes used within this page
 154          */
 155         unsigned int            used;
 156         /*
 157          * cpu that owns this page
 158          */
 159         unsigned short          cpu;
 160         /*
 161          * type(context) of this page
 162          */
 163         unsigned short          type;
 164 };
 165
 166 int cfs_tcd_owns_tage(struct cfs_trace_cpu_data *tcd,
 167                       struct cfs_trace_page *tage);
 168
 169 extern void cfs_trace_assertion_failed(const char *str,
 170                                        struct libcfs_debug_msg_data *m);
 171
 172 /* ASSERTION that is safe to use within the debug system */
 173 #define __LASSERT(cond)                                                 \
 174 do {                                                                    \
 175         if (unlikely(!(cond))) {                                        \
 176                 LIBCFS_DEBUG_MSG_DATA_DECL(msgdata, D_EMERG, NULL);     \
 177                 cfs_trace_assertion_failed("ASSERTION("#cond") failed", \
 178                                            &msgdata);                   \
 179         }                                                               \
 180 } while (0)
 181
 182 #define __LASSERT_TAGE_INVARIANT(tage)                                  \
 183 do {                                                                    \
 184         __LASSERT(tage != NULL);                                        \
 185         __LASSERT(tage->page != NULL);                                  \
 186         __LASSERT(tage->used <= PAGE_SIZE);                             \
 187         __LASSERT(page_count(tage->page) > 0);                          \
 188 } while (0)
 189
 190 #endif /* __LIBCFS_TRACEFILE_H__ */