tracefile.c

来自「lustre 1.6.5 source code」· C语言 代码 · 共 1,115 行 · 第 1/3 页

/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
 * vim:expandtab:shiftwidth=8:tabstop=8:
 *
 * Copyright (C) 2004 Cluster File Systems, Inc.
 *   Author: Zach Brown <[e-mail]>
 *   Author: Phil Schwan <[e-mail]>
 *
 *   This file is part of Lustre, http://www.lustre.org.
 *
 *   Lustre is free software; you can redistribute it and/or
 *   modify it under the terms of version 2 of the GNU General Public
 *   License as published by the Free Software Foundation.
 *
 *   Lustre 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 for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with Lustre; if not, write to the Free Software
 *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */


#define DEBUG_SUBSYSTEM S_LNET
#define LUSTRE_TRACEFILE_PRIVATE
#include "tracefile.h"

#include <libcfs/kp30.h>
#include <libcfs/libcfs.h>

/* XXX move things up to the top, comment */
union trace_data_union (*trace_data[TCD_MAX_TYPES])[NR_CPUS] __cacheline_aligned;

char tracefile[TRACEFILE_NAME_SIZE];
long long tracefile_size = TRACEFILE_SIZE;
static struct tracefiled_ctl trace_tctl;
struct semaphore trace_thread_sem;
static int thread_running = 0;

atomic_t tage_allocated = ATOMIC_INIT(0);

static void put_pages_on_tcd_daemon_list(struct page_collection *pc,
                                         struct trace_cpu_data *tcd);

static inline struct trace_page *tage_from_list(struct list_head *list)
{
        return list_entry(list, struct trace_page, linkage);
}

static struct trace_page *tage_alloc(int gfp)
{
        cfs_page_t        *page;
        struct trace_page *tage;

        /*
         * Don't spam console with allocation failures: they will be reported
         * by upper layer anyway.
         */
        gfp |= CFS_ALLOC_NOWARN;
        page = cfs_alloc_page(gfp);
        if (page == NULL)
                return NULL;

        tage = cfs_alloc(sizeof(*tage), gfp);
        if (tage == NULL) {
                cfs_free_page(page);
                return NULL;
        }

        tage->page = page;
        atomic_inc(&tage_allocated);
        return tage;
}

static void tage_free(struct trace_page *tage)
{
        __LASSERT(tage != NULL);
        __LASSERT(tage->page != NULL);

        cfs_free_page(tage->page);
        cfs_free(tage);
        atomic_dec(&tage_allocated);
}

static void tage_to_tail(struct trace_page *tage, struct list_head *queue)
{
        __LASSERT(tage != NULL);
        __LASSERT(queue != NULL);

        list_move_tail(&tage->linkage, queue);
}

int trace_refill_stock(struct trace_cpu_data *tcd, int gfp,
                       struct list_head *stock)
{
        int i;

        /*
         * XXX nikita: do NOT call portals_debug_msg() (CDEBUG/ENTRY/EXIT)
         * from here: this will lead to infinite recursion.
         */

        for (i = 0; i + tcd->tcd_cur_stock_pages < TCD_STOCK_PAGES ; ++ i) {
                struct trace_page *tage;

                tage = tage_alloc(gfp);
                if (tage == NULL)
                        break;
                list_add_tail(&tage->linkage, stock);
        }
        return i;
}

/* return a page that has 'len' bytes left at the end */
static struct trace_page *trace_get_tage_try(struct trace_cpu_data *tcd,
                                             unsigned long len)
{
        struct trace_page *tage;

        if (tcd->tcd_cur_pages > 0) {
                __LASSERT(!list_empty(&tcd->tcd_pages));
                tage = tage_from_list(tcd->tcd_pages.prev);
                if (tage->used + len <= CFS_PAGE_SIZE)
                        return tage;
        }

        if (tcd->tcd_cur_pages < tcd->tcd_max_pages) {
                if (tcd->tcd_cur_stock_pages > 0) {
                        tage = tage_from_list(tcd->tcd_stock_pages.prev);
                        -- tcd->tcd_cur_stock_pages;
                        list_del_init(&tage->linkage);
                } else {
                        tage = tage_alloc(CFS_ALLOC_ATOMIC);
                        if (tage == NULL) {
                                printk(KERN_WARNING
                                       "failure to allocate a tage (%ld)\n",
                                       tcd->tcd_cur_pages);
                                return NULL;
                        }
                }

                tage->used = 0;
                tage->cpu = smp_processor_id();
                tage->type = tcd->tcd_type;
                list_add_tail(&tage->linkage, &tcd->tcd_pages);
                tcd->tcd_cur_pages++;

                if (tcd->tcd_cur_pages > 8 && thread_running) {
                        struct tracefiled_ctl *tctl = &trace_tctl;
                        /*
                         * wake up tracefiled to process some pages.
                         */
                        cfs_waitq_signal(&tctl->tctl_waitq);
                }
                return tage;
        }
        return NULL;
}

static void tcd_shrink(struct trace_cpu_data *tcd)
{
        int pgcount = tcd->tcd_cur_pages / 10;
        struct page_collection pc;
        struct trace_page *tage;
        struct trace_page *tmp;

	/*
	 * XXX nikita: do NOT call portals_debug_msg() (CDEBUG/ENTRY/EXIT)
	 * from here: this will lead to infinite recursion.
	 */

        printk(KERN_WARNING "debug daemon buffer overflowed; discarding"
               " 10%% of pages (%d of %ld)\n", pgcount + 1, tcd->tcd_cur_pages);

        CFS_INIT_LIST_HEAD(&pc.pc_pages);
        spin_lock_init(&pc.pc_lock);

        list_for_each_entry_safe(tage, tmp, &tcd->tcd_pages, linkage) {
                if (pgcount-- == 0)
                        break;

                list_move_tail(&tage->linkage, &pc.pc_pages);
                tcd->tcd_cur_pages--;
        }
        put_pages_on_tcd_daemon_list(&pc, tcd);
}

/* return a page that has 'len' bytes left at the end */
static struct trace_page *trace_get_tage(struct trace_cpu_data *tcd,
                                         unsigned long len)
{
        struct trace_page *tage;

	/*
	 * XXX nikita: do NOT call portals_debug_msg() (CDEBUG/ENTRY/EXIT)
	 * from here: this will lead to infinite recursion.
	 */

        if (len > CFS_PAGE_SIZE) {
                printk(KERN_ERR
                       "cowardly refusing to write %lu bytes in a page\n", len);
                return NULL;
        }

        tage = trace_get_tage_try(tcd, len);
        if (tage != NULL)
                return tage;
        if (thread_running)
                tcd_shrink(tcd);
        if (tcd->tcd_cur_pages > 0) {
                tage = tage_from_list(tcd->tcd_pages.next);
                tage->used = 0;
                tage_to_tail(tage, &tcd->tcd_pages);
        }
        return tage;
}

int libcfs_debug_vmsg2(cfs_debug_limit_state_t *cdls, int subsys, int mask,
                       const char *file, const char *fn, const int line,
                       const char *format1, va_list args,
                       const char *format2, ...)		       
{
        struct trace_cpu_data   *tcd = NULL;
        struct ptldebug_header   header;
        struct trace_page       *tage;
        /* string_buf is used only if tcd != NULL, and is always set then */
        char                    *string_buf = NULL;
        char                    *debug_buf;
        int                      known_size;
        int                      needed = 85; /* average message length */
        int                      max_nob;
        va_list                  ap;
        int                      depth;
        int                      i;
        int                      remain;

        if (strchr(file, '/'))
                file = strrchr(file, '/') + 1;


        set_ptldebug_header(&header, subsys, mask, line, CDEBUG_STACK());

        tcd = trace_get_tcd();
        if (tcd == NULL)                /* arch may not log in IRQ context */
                goto console;

        if (tcd->tcd_shutting_down) {
                trace_put_tcd(tcd);
                tcd = NULL;
                goto console;
        }

        depth = __current_nesting_level();
        known_size = strlen(file) + 1 + depth;
        if (fn)
                known_size += strlen(fn) + 1;

        if (libcfs_debug_binary)
                known_size += sizeof(header);

        /*/
         * '2' used because vsnprintf return real size required for output
         * _without_ terminating NULL.
         * if needed is to small for this format.
         */
        for (i=0;i<2;i++) {
                tage = trace_get_tage(tcd, needed + known_size + 1);
                if (tage == NULL) {
                        if (needed + known_size > CFS_PAGE_SIZE)
                                mask |= D_ERROR;

                        trace_put_tcd(tcd);
                        tcd = NULL;
                        goto console;
                }

                string_buf = (char *)cfs_page_address(tage->page)+tage->used+known_size;

                max_nob = CFS_PAGE_SIZE - tage->used - known_size;
                if (max_nob <= 0) {
                        printk(KERN_EMERG "negative max_nob: %i\n", max_nob);
                        mask |= D_ERROR;
                        trace_put_tcd(tcd);
                        tcd = NULL;
                        goto console;
                }

                needed = 0;
                if (format1) {
                        va_copy(ap, args);
                        needed = vsnprintf(string_buf, max_nob, format1, ap);
                        va_end(ap);
                }
		

                if (format2) {
		        remain = max_nob - needed;
                        if (remain < 0)
                                remain = 0;
		
                        va_start(ap, format2);
                        needed += vsnprintf(string_buf+needed, remain, format2, ap);
                        va_end(ap);
                }

                if (needed < max_nob) /* well. printing ok.. */
                        break;
        }
	
        if (*(string_buf+needed-1) != '\n')
                printk(KERN_INFO "format at %s:%d:%s doesn't end in newline\n",
                       file, line, fn);
	
        header.ph_len = known_size + needed;
        debug_buf = (char *)cfs_page_address(tage->page) + tage->used;

        if (libcfs_debug_binary) {
                memcpy(debug_buf, &header, sizeof(header));
                tage->used += sizeof(header);
                debug_buf += sizeof(header);
        }

        /* indent message according to the nesting level */
        while (depth-- > 0) {
                *(debug_buf++) = '.';
                ++ tage->used;
        }

        strcpy(debug_buf, file);
        tage->used += strlen(file) + 1;
        debug_buf += strlen(file) + 1;

        if (fn) {
                strcpy(debug_buf, fn);
                tage->used += strlen(fn) + 1;
                debug_buf += strlen(fn) + 1;
        }

        __LASSERT(debug_buf == string_buf);

        tage->used += needed;
        __LASSERT (tage->used <= CFS_PAGE_SIZE);

console:
        if ((mask & libcfs_printk) == 0) {
                /* no console output requested */
                if (tcd != NULL)
                        trace_put_tcd(tcd);
                return 1;
        }

        if (cdls != NULL) {
                if (libcfs_console_ratelimit &&
                    cdls->cdls_next != 0 &&     /* not first time ever */
                    !cfs_time_after(cfs_time_current(), cdls->cdls_next)) {
                        /* skipping a console message */
                        cdls->cdls_count++;
                        if (tcd != NULL)
                                trace_put_tcd(tcd);
                        return 1;
                }

                if (cfs_time_after(cfs_time_current(), cdls->cdls_next +
                                                       libcfs_console_max_delay
                                                       + cfs_time_seconds(10))) {
                        /* last timeout was a long time ago */
                        cdls->cdls_delay /= libcfs_console_backoff * 4;
                } else {
                        cdls->cdls_delay *= libcfs_console_backoff;

                        if (cdls->cdls_delay < libcfs_console_min_delay)