ae6706f067
And put this into net/dccp/ccids/lib/, where packet_history.[ch] will also be moved and then we'll have a tfrc_lib.ko module that will be used by dccp_ccid3.ko and other CCIDs that are variations of TFRC (RFC 3448). Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com> Signed-off-by: David S. Miller <davem@davemloft.net>
144 lines
3.5 KiB
C
144 lines
3.5 KiB
C
/*
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* net/dccp/ccids/lib/loss_interval.c
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*
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* Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand.
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* Copyright (c) 2005 Ian McDonald <iam4@cs.waikato.ac.nz>
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* Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*/
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#include <linux/config.h>
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#include <linux/module.h>
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#include "loss_interval.h"
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struct dccp_li_hist *dccp_li_hist_new(const char *name)
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{
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struct dccp_li_hist *hist = kmalloc(sizeof(*hist), GFP_ATOMIC);
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static const char dccp_li_hist_mask[] = "li_hist_%s";
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char *slab_name;
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if (hist == NULL)
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goto out;
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slab_name = kmalloc(strlen(name) + sizeof(dccp_li_hist_mask) - 1,
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GFP_ATOMIC);
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if (slab_name == NULL)
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goto out_free_hist;
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sprintf(slab_name, dccp_li_hist_mask, name);
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hist->dccplih_slab = kmem_cache_create(slab_name,
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sizeof(struct dccp_li_hist_entry),
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0, SLAB_HWCACHE_ALIGN,
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NULL, NULL);
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if (hist->dccplih_slab == NULL)
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goto out_free_slab_name;
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out:
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return hist;
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out_free_slab_name:
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kfree(slab_name);
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out_free_hist:
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kfree(hist);
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hist = NULL;
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goto out;
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}
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EXPORT_SYMBOL_GPL(dccp_li_hist_new);
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void dccp_li_hist_delete(struct dccp_li_hist *hist)
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{
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const char* name = kmem_cache_name(hist->dccplih_slab);
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kmem_cache_destroy(hist->dccplih_slab);
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kfree(name);
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kfree(hist);
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}
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EXPORT_SYMBOL_GPL(dccp_li_hist_delete);
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void dccp_li_hist_purge(struct dccp_li_hist *hist, struct list_head *list)
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{
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struct dccp_li_hist_entry *entry, *next;
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list_for_each_entry_safe(entry, next, list, dccplih_node) {
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list_del_init(&entry->dccplih_node);
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kmem_cache_free(hist->dccplih_slab, entry);
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}
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}
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EXPORT_SYMBOL_GPL(dccp_li_hist_purge);
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/* Weights used to calculate loss event rate */
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/*
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* These are integers as per section 8 of RFC3448. We can then divide by 4 *
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* when we use it.
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*/
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static const int dccp_li_hist_w[DCCP_LI_HIST_IVAL_F_LENGTH] = {
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4, 4, 4, 4, 3, 2, 1, 1,
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};
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u32 dccp_li_hist_calc_i_mean(struct list_head *list)
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{
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struct dccp_li_hist_entry *li_entry, *li_next;
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int i = 0;
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u32 i_tot;
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u32 i_tot0 = 0;
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u32 i_tot1 = 0;
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u32 w_tot = 0;
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list_for_each_entry_safe(li_entry, li_next, list, dccplih_node) {
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if (i < DCCP_LI_HIST_IVAL_F_LENGTH) {
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i_tot0 += li_entry->dccplih_interval * dccp_li_hist_w[i];
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w_tot += dccp_li_hist_w[i];
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}
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if (i != 0)
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i_tot1 += li_entry->dccplih_interval * dccp_li_hist_w[i - 1];
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if (++i > DCCP_LI_HIST_IVAL_F_LENGTH)
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break;
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}
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if (i != DCCP_LI_HIST_IVAL_F_LENGTH)
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return 0;
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i_tot = max(i_tot0, i_tot1);
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/* FIXME: Why do we do this? -Ian McDonald */
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if (i_tot * 4 < w_tot)
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i_tot = w_tot * 4;
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return i_tot * 4 / w_tot;
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}
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EXPORT_SYMBOL_GPL(dccp_li_hist_calc_i_mean);
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struct dccp_li_hist_entry *dccp_li_hist_interval_new(struct dccp_li_hist *hist,
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struct list_head *list,
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const u64 seq_loss,
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const u8 win_loss)
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{
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struct dccp_li_hist_entry *tail = NULL, *entry;
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int i;
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for (i = 0; i <= DCCP_LI_HIST_IVAL_F_LENGTH; ++i) {
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entry = dccp_li_hist_entry_new(hist, SLAB_ATOMIC);
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if (entry == NULL) {
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dccp_li_hist_purge(hist, list);
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return NULL;
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}
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if (tail == NULL)
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tail = entry;
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list_add(&entry->dccplih_node, list);
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}
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entry->dccplih_seqno = seq_loss;
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entry->dccplih_win_count = win_loss;
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return tail;
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}
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EXPORT_SYMBOL_GPL(dccp_li_hist_interval_new);
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