libcfs/libcfs/tracefile.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2
   3 /*
   4  * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
   5  * Use is subject to license terms.
   6  *
   7  * Copyright (c) 2012, 2017, Intel Corporation.
   8  */
   9
  10 /*
  11  * This file is part of Lustre, http://www.lustre.org/
  12  */
  13
  14 #ifndef __LIBCFS_TRACEFILE_H__
  15 #define __LIBCFS_TRACEFILE_H__
  16
  17 #include <libcfs/libcfs.h>
  18
  19 #define TRACEFILE_NAME_SIZE 1024
  20 extern char      cfs_tracefile[TRACEFILE_NAME_SIZE];
  21 extern long long cfs_tracefile_size;
  22
  23 /**
  24  * The path of debug log dump upcall script.
  25  */
  26 extern char lnet_debug_log_upcall[1024];
  27
  28 int cfs_tracefile_dump_all_pages(char *filename);
  29 void cfs_trace_debug_print(void);
  30 void cfs_trace_flush_pages(void);
  31 int cfs_trace_start_thread(void);
  32 void cfs_trace_stop_thread(void);
  33 int cfs_tracefile_init(int max_pages);
  34 void cfs_tracefile_exit(void);
  35
  36
  37
  38 int cfs_trace_copyout_string(char __user *usr_buffer, int usr_buffer_nob,
  39                              const char *knl_str, char *append);
  40 int cfs_trace_dump_debug_buffer_usrstr(void __user *usr_str, int usr_str_nob);
  41 int cfs_trace_daemon_command(char *str);
  42 int cfs_trace_daemon_command_usrstr(void __user *usr_str, int usr_str_nob);
  43 int cfs_trace_set_debug_mb(int mb);
  44 int cfs_trace_get_debug_mb(void);
  45
  46 extern int  libcfs_panic_in_progress;
  47
  48 #define TCD_MAX_PAGES (5 << (20 - PAGE_SHIFT))
  49 #define TCD_STOCK_PAGES (TCD_MAX_PAGES)
  50 #define CFS_TRACEFILE_SIZE (500 << 20)
  51
  52 union cfs_trace_data_union {
  53         struct cfs_trace_cpu_data {
  54                 /*
  55                  * Even though this structure is meant to be per-CPU, locking
  56                  * is needed because in some places the data may be accessed
  57                  * from other CPUs. This lock is directly used in trace_get_tcd
  58                  * and trace_put_tcd, which are called in libcfs_debug_msg and
  59                  * tcd_for_each_type_lock
  60                  */
  61                 spinlock_t              tcd_lock;
  62                 unsigned long           tcd_lock_flags;
  63
  64                 /*
  65                  * pages with trace records not yet processed by tracefiled.
  66                  */
  67                 struct list_head        tcd_pages;
  68                 /* number of pages on ->tcd_pages */
  69                 unsigned long           tcd_cur_pages;
  70
  71                 /*
  72                  * Maximal number of pages allowed on ->tcd_pages
  73                  * Always TCD_MAX_PAGES * tcd_pages_factor / 100 in current
  74                  * implementation.
  75                  */
  76                 unsigned long           tcd_max_pages;
  77
  78                 /*
  79                  * preallocated pages to write trace records into. Pages from
  80                  * ->tcd_stock_pages are moved to ->tcd_pages by
  81                  * portals_debug_msg().
  82                  *
  83                  * This list is necessary, because on some platforms it's
  84                  * impossible to perform efficient atomic page allocation in a
  85                  * non-blockable context.
  86                  *
  87                  * Such platforms fill ->tcd_stock_pages "on occasion", when
  88                  * tracing code is entered in blockable context.
  89                  *
  90                  * trace_get_tage_try() tries to get a page from
  91                  * ->tcd_stock_pages first and resorts to atomic page
  92                  * allocation only if this queue is empty. ->tcd_stock_pages
  93                  * is replenished when tracing code is entered in blocking
  94                  * context (darwin-tracefile.c:trace_get_tcd()). We try to
  95                  * maintain TCD_STOCK_PAGES (40 by default) pages in this
  96                  * queue. Atomic allocation is only required if more than
  97                  * TCD_STOCK_PAGES pagesful are consumed by trace records all
  98                  * emitted in non-blocking contexts. Which is quite unlikely.
  99                  */
 100                 struct list_head        tcd_stock_pages;
 101                 /* number of pages on ->tcd_stock_pages */
 102                 unsigned long           tcd_cur_stock_pages;
 103
 104                 unsigned short          tcd_shutting_down;
 105                 unsigned short          tcd_cpu;
 106                 unsigned short          tcd_type;
 107                 /* The factors to share debug memory. */
 108                 unsigned short          tcd_pages_factor;
 109         } tcd;
 110         char __pad[L1_CACHE_ALIGN(sizeof(struct cfs_trace_cpu_data))];
 111 };
 112
 113 /* XXX nikita: this declaration is internal to tracefile.c and should probably
 114  * be moved there */
 115 struct page_collection {
 116         struct list_head        pc_pages;
 117 };
 118
 119 /*
 120  * small data-structure for each page owned by tracefiled.
 121  */
 122 /* XXX nikita: this declaration is internal to tracefile.c and should probably
 123  * be moved there */
 124 struct cfs_trace_page {
 125         /*
 126          * page itself
 127          */
 128         struct page             *page;
 129         /*
 130          * linkage into one of the lists in trace_data_union or
 131          * page_collection
 132          */
 133         struct list_head        linkage;
 134         /*
 135          * number of bytes used within this page
 136          */
 137         unsigned int            used;
 138         /*
 139          * cpu that owns this page
 140          */
 141         unsigned short          cpu;
 142         /*
 143          * type(context) of this page
 144          */
 145         unsigned short          type;
 146 };
 147
 148 int cfs_tcd_owns_tage(struct cfs_trace_cpu_data *tcd,
 149                       struct cfs_trace_page *tage);
 150
 151 extern void cfs_trace_assertion_failed(const char *str,
 152                                        struct libcfs_debug_msg_data *m);
 153
 154 /* ASSERTION that is safe to use within the debug system */
 155 #define __LASSERT(cond)                                                 \
 156 do {                                                                    \
 157         if (unlikely(!(cond))) {                                        \
 158                 LIBCFS_DEBUG_MSG_DATA_DECL(msgdata, D_EMERG, NULL);     \
 159                 cfs_trace_assertion_failed("ASSERTION("#cond") failed", \
 160                                            &msgdata);                   \
 161         }                                                               \
 162 } while (0)
 163
 164 #define __LASSERT_TAGE_INVARIANT(tage)                                  \
 165 do {                                                                    \
 166         __LASSERT(tage != NULL);                                        \
 167         __LASSERT(tage->page != NULL);                                  \
 168         __LASSERT(tage->used <= PAGE_SIZE);                             \
 169         __LASSERT(page_count(tage->page) > 0);                          \
 170 } while (0)
 171
 172 #endif /* __LIBCFS_TRACEFILE_H__ */