include/spl-trace.h

   1 /*****************************************************************************\
   2  *  Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
   3  *  Copyright (C) 2007 The Regents of the University of California.
   4  *  Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
   5  *  Written by Brian Behlendorf <behlendorf1@llnl.gov>.
   6  *  UCRL-CODE-235197
   7  *
   8  *  This file is part of the SPL, Solaris Porting Layer.
   9  *  For details, see <http://zfsonlinux.org/>.
  10  *
  11  *  The SPL is free software; you can redistribute it and/or modify it
  12  *  under the terms of the GNU General Public License as published by the
  13  *  Free Software Foundation; either version 2 of the License, or (at your
  14  *  option) any later version.
  15  *
  16  *  The SPL is distributed in the hope that it will be useful, but WITHOUT
  17  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  18  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  19  *  for more details.
  20  *
  21  *  You should have received a copy of the GNU General Public License along
  22  *  with the SPL.  If not, see <http://www.gnu.org/licenses/>.
  23 \*****************************************************************************/
  24
  25 #ifndef _SPL_TRACE_H
  26 #define _SPL_TRACE_H
  27
  28 #define TCD_MAX_PAGES                   (5 << (20 - PAGE_SHIFT))
  29 #define TCD_STOCK_PAGES                 (TCD_MAX_PAGES)
  30 #define TRACE_CONSOLE_BUFFER_SIZE       1024
  31
  32 #define SPL_DEFAULT_MAX_DELAY           (600 * HZ)
  33 #define SPL_DEFAULT_MIN_DELAY           ((HZ + 1) / 2)
  34 #define SPL_DEFAULT_BACKOFF             2
  35
  36 #define DL_NOTHREAD                     0x0001 /* Do not create a new thread */
  37 #define DL_SINGLE_CPU                   0x0002 /* Collect pages from this CPU*/
  38
  39 typedef struct dumplog_priv {
  40         wait_queue_head_t       dp_waitq;
  41         pid_t                   dp_pid;
  42         int                     dp_flags;
  43         atomic_t                dp_done;
  44 } dumplog_priv_t;
  45
  46 /* Three trace data types */
  47 typedef enum {
  48         TCD_TYPE_PROC,
  49         TCD_TYPE_SOFTIRQ,
  50         TCD_TYPE_IRQ,
  51         TCD_TYPE_MAX
  52 } tcd_type_t;
  53
  54 union trace_data_union {
  55         struct trace_cpu_data {
  56                 /* pages with trace records not yet processed by tracefiled */
  57                 struct list_head        tcd_pages;
  58                 /* number of pages on ->tcd_pages */
  59                 unsigned long   tcd_cur_pages;
  60                 /* Max number of pages allowed on ->tcd_pages */
  61                 unsigned long   tcd_max_pages;
  62
  63                 /*
  64                  * preallocated pages to write trace records into. Pages from
  65                  * ->tcd_stock_pages are moved to ->tcd_pages by spl_debug_msg().
  66                  *
  67                  * This list is necessary, because on some platforms it's
  68                  * impossible to perform efficient atomic page allocation in a
  69                  * non-blockable context.
  70                  *
  71                  * Such platforms fill ->tcd_stock_pages "on occasion", when
  72                  * tracing code is entered in blockable context.
  73                  *
  74                  * trace_get_tage_try() tries to get a page from
  75                  * ->tcd_stock_pages first and resorts to atomic page
  76                  * allocation only if this queue is empty. ->tcd_stock_pages
  77                  * is replenished when tracing code is entered in blocking
  78                  * context (darwin-tracefile.c:trace_get_tcd()). We try to
  79                  * maintain TCD_STOCK_PAGES (40 by default) pages in this
  80                  * queue. Atomic allocation is only required if more than
  81                  * TCD_STOCK_PAGES pagesful are consumed by trace records all
  82                  * emitted in non-blocking contexts. Which is quite unlikely.
  83                  */
  84                 struct list_head        tcd_stock_pages;
  85                 /* number of pages on ->tcd_stock_pages */
  86                 unsigned long   tcd_cur_stock_pages;
  87
  88                 unsigned short  tcd_shutting_down;
  89                 unsigned short  tcd_cpu;
  90                 unsigned short  tcd_type;
  91                 /* The factors to share debug memory. */
  92                 unsigned short  tcd_pages_factor;
  93
  94                 /*
  95                  * This spinlock is needed to workaround the problem of
  96                  * set_cpus_allowed() being GPL-only. Since we cannot
  97                  * schedule a thread on a specific CPU when dumping the
  98                  * pages, we must use the spinlock for mutual exclusion.
  99                  */
 100                 spinlock_t      tcd_lock;
 101                 unsigned long   tcd_lock_flags;
 102         } tcd;
 103         char __pad[L1_CACHE_ALIGN(sizeof(struct trace_cpu_data))];
 104 };
 105
 106 extern union trace_data_union (*trace_data[TCD_TYPE_MAX])[NR_CPUS];
 107
 108 #define tcd_for_each(tcd, i, j)                                         \
 109     for (i = 0; i < TCD_TYPE_MAX && trace_data[i]; i++)                 \
 110         for (j = 0, ((tcd) = &(*trace_data[i])[j].tcd);                 \
 111              j < num_possible_cpus(); j++, (tcd) = &(*trace_data[i])[j].tcd)
 112
 113 #define tcd_for_each_type_lock(tcd, i, cpu)                             \
 114     for (i = 0; i < TCD_TYPE_MAX && trace_data[i] &&                    \
 115          (tcd = &(*trace_data[i])[cpu].tcd) &&                          \
 116          trace_lock_tcd(tcd); trace_unlock_tcd(tcd), i++)
 117
 118 struct trace_page {
 119         struct page     *page;    /* page itself */
 120         struct list_head linkage;  /* Used by trace_data_union */
 121         unsigned int    used;     /* number of bytes used within this page */
 122         unsigned short  cpu;      /* cpu that owns this page */
 123         unsigned short  type;     /* type(context) of this page */
 124 };
 125
 126 struct page_collection {
 127         struct list_head pc_pages;
 128         spinlock_t      pc_lock;
 129         int             pc_want_daemon_pages;
 130 };
 131
 132 #endif /* SPL_TRACE_H */