[TFRC]: Cache allocation of entries
This updates and simplifies the allocation of kmem_cache entries with regard
to the new structure.
Main changes:
1. On-demand allocation: no memory consumption when running over loss-free links.
2. Since cache allocation is local to the module, the cache constructor/destructor
have been integrated into the module initialisation/cleanup routines.
Signed-off-by: Gerrit Renker <gerrit@xxxxxxxxxxxxxx>
---
net/dccp/ccids/ccid3.c | 25 +--------
net/dccp/ccids/lib/loss_interval.c | 93 +++++++++----------------------------
net/dccp/ccids/lib/loss_interval.h | 22 --------
net/dccp/ccids/lib/tfrc_module.c | 8 ++-
4 files changed, 36 insertions(+), 112 deletions(-)
--- a/net/dccp/ccids/lib/tfrc_module.c
+++ b/net/dccp/ccids/lib/tfrc_module.c
@@ -6,12 +6,17 @@
#include "tfrc.h"
/* Initialisation / Clean-up routines */
+extern int li_init(void);
+extern void li_cleanup(void);
extern int packet_history_init(void);
extern void packet_history_cleanup(void);
static int __init tfrc_module_init(void)
{
- int rc = packet_history_init();
+ int rc = li_init();
+
+ if (rc == 0)
+ rc = packet_history_init();
return rc;
}
@@ -19,6 +24,7 @@ static int __init tfrc_module_init(void)
static void __exit tfrc_module_exit(void)
{
packet_history_cleanup();
+ li_cleanup();
}
module_init(tfrc_module_init);
--- a/net/dccp/ccids/lib/loss_interval.h
+++ b/net/dccp/ccids/lib/loss_interval.h
@@ -40,9 +40,6 @@ struct tfrc_loss_interval {
u32 li_length;
};
-extern struct dccp_li_hist *dccp_li_hist_new(const char *name);
-extern void dccp_li_hist_delete(struct dccp_li_hist *hist);
-
/**
* tfrc_loss_hist - Loss record database
* @ring: Circular queue managed in LIFO manner
@@ -68,25 +65,8 @@ static inline u8 tfrc_lh_length(struct t
return min(lh->counter, (u8)LIH_SIZE);
}
-static inline struct dccp_li_hist_entry *
- dccp_li_hist_entry_new(struct dccp_li_hist *hist,
- const gfp_t prio)
-{
- return kmem_cache_alloc(hist->dccplih_slab, prio);
-}
-
-static inline void dccp_li_hist_entry_delete(struct dccp_li_hist *hist,
- struct dccp_li_hist_entry *entry)
-{
- if (entry != NULL)
- kmem_cache_free(hist->dccplih_slab, entry);
-}
-
-extern void dccp_li_hist_purge(struct dccp_li_hist *hist,
- struct list_head *list);
+extern void tfrc_lh_cleanup(struct tfrc_loss_hist *lh);
extern u32 dccp_li_hist_calc_i_mean(struct list_head *list);
-extern int dccp_li_hist_interval_new(struct dccp_li_hist *hist,
- struct list_head *list, const u64 seq_loss, const u8 win_loss);
#endif /* _DCCP_LI_HIST_ */
--- a/net/dccp/ccids/lib/loss_interval.c
+++ b/net/dccp/ccids/lib/loss_interval.c
@@ -16,6 +16,8 @@
#include "../../dccp.h"
#include "loss_interval.h"
+static struct kmem_cache *tfrc_lh_slab;
+
/*
* Access macros: These require that at least one entry is present in lh,
* and implement array semantics (0 is first, n-1 is the last of n entries).
@@ -37,61 +39,25 @@ static inline struct tfrc_loss_interval
return lh->counter ? __curr_entry(lh) : NULL;
}
-struct dccp_li_hist *dccp_li_hist_new(const char *name)
+/*
+ * On-demand allocation and de-allocation of entries
+ */
+static struct tfrc_loss_interval *tfrc_lh_demand_next(struct tfrc_loss_hist *lh)
{
- struct dccp_li_hist *hist = kmalloc(sizeof(*hist), GFP_ATOMIC);
- static const char dccp_li_hist_mask[] = "li_hist_%s";
- char *slab_name;
-
- if (hist == NULL)
- goto out;
-
- slab_name = kmalloc(strlen(name) + sizeof(dccp_li_hist_mask) - 1,
- GFP_ATOMIC);
- if (slab_name == NULL)
- goto out_free_hist;
+ if (__next_entry(lh) == NULL)
+ __next_entry(lh) = kmem_cache_alloc(tfrc_lh_slab, GFP_ATOMIC);
- sprintf(slab_name, dccp_li_hist_mask, name);
- hist->dccplih_slab = kmem_cache_create(slab_name,
- sizeof(struct dccp_li_hist_entry),
- 0, SLAB_HWCACHE_ALIGN,
- NULL, NULL);
- if (hist->dccplih_slab == NULL)
- goto out_free_slab_name;
-out:
- return hist;
-out_free_slab_name:
- kfree(slab_name);
-out_free_hist:
- kfree(hist);
- hist = NULL;
- goto out;
+ return __next_entry(lh);
}
-EXPORT_SYMBOL_GPL(dccp_li_hist_new);
-
-void dccp_li_hist_delete(struct dccp_li_hist *hist)
+void tfrc_lh_cleanup(struct tfrc_loss_hist *lh)
{
- const char* name = kmem_cache_name(hist->dccplih_slab);
-
- kmem_cache_destroy(hist->dccplih_slab);
- kfree(name);
- kfree(hist);
+ if (tfrc_lh_is_initialised(lh))
+ for (lh->counter = 0; lh->counter < LIH_SIZE; lh->counter++)
+ if (__next_entry(lh) != NULL)
+ kmem_cache_free(tfrc_lh_slab, __next_entry(lh));
}
-
-EXPORT_SYMBOL_GPL(dccp_li_hist_delete);
-
-void dccp_li_hist_purge(struct dccp_li_hist *hist, struct list_head *list)
-{
- struct dccp_li_hist_entry *entry, *next;
-
- list_for_each_entry_safe(entry, next, list, dccplih_node) {
- list_del_init(&entry->dccplih_node);
- kmem_cache_free(hist->dccplih_slab, entry);
- }
-}
-
-EXPORT_SYMBOL_GPL(dccp_li_hist_purge);
+EXPORT_SYMBOL_GPL(tfrc_lh_cleanup);
/* Weights used to calculate loss event rate */
/*
@@ -139,26 +105,17 @@ u32 dccp_li_hist_calc_i_mean(struct list
EXPORT_SYMBOL_GPL(dccp_li_hist_calc_i_mean);
-int dccp_li_hist_interval_new(struct dccp_li_hist *hist,
- struct list_head *list, const u64 seq_loss, const u8 win_loss)
+int __init li_init(void)
{
- struct dccp_li_hist_entry *entry;
- int i;
+ tfrc_lh_slab = kmem_cache_create("tfrc_loss_history",
+ sizeof(struct tfrc_loss_interval),
+ 0, SLAB_HWCACHE_ALIGN, NULL, NULL);
- for (i = 0; i < DCCP_LI_HIST_IVAL_F_LENGTH; i++) {
- entry = dccp_li_hist_entry_new(hist, GFP_ATOMIC);
- if (entry == NULL) {
- dccp_li_hist_purge(hist, list);
- DCCP_BUG("loss interval list entry is NULL");
- return 0;
- }
- entry->dccplih_interval = ~0;
- list_add(&entry->dccplih_node, list);
- }
-
- entry->dccplih_seqno = seq_loss;
- entry->dccplih_win_count = win_loss;
- return 1;
+ return tfrc_lh_slab == NULL? -ENOBUFS : 0;
}
-EXPORT_SYMBOL_GPL(dccp_li_hist_interval_new);
+void __exit li_cleanup(void)
+{
+ if (tfrc_lh_slab != NULL)
+ kmem_cache_destroy(tfrc_lh_slab);
+}
--- a/net/dccp/ccids/ccid3.c
+++ b/net/dccp/ccids/ccid3.c
@@ -48,7 +48,6 @@ static int ccid3_debug;
#endif
DECLARE_TFRC_TX_CACHE(ccid3_tx_hist);
-static struct dccp_li_hist *ccid3_li_hist;
/*
* Transmitter Half-Connection Routines
@@ -908,7 +907,7 @@ static int ccid3_hc_rx_init(struct ccid
if (tfrc_rx_hist_init(&hcrx->ccid3hcrx_hist))
return 1;
- INIT_LIST_HEAD(&hcrx->ccid3hcrx_li_hist);
+ tfrc_lh_init(&hcrx->ccid3hcrx_li_hist);
hcrx->ccid3hcrx_state = TFRC_RSTATE_NO_DATA;
hcrx->ccid3hcrx_s = 0;
hcrx->ccid3hcrx_rtt = 0;
@@ -922,9 +921,7 @@ static void ccid3_hc_rx_exit(struct sock
ccid3_hc_rx_set_state(sk, TFRC_RSTATE_TERM);
tfrc_rx_hist_cleanup(&hcrx->ccid3hcrx_hist);
-
- /* Empty loss interval history */
- dccp_li_hist_purge(ccid3_li_hist, &hcrx->ccid3hcrx_li_hist);
+ tfrc_lh_cleanup(&hcrx->ccid3hcrx_li_hist);
}
static void ccid3_hc_rx_get_info(struct sock *sk, struct tcp_info *info)
@@ -1001,22 +998,11 @@ static __init int ccid3_module_init(void
if (tfrc_tx_cache_init(&ccid3_tx_hist, "ccid3"))
goto out;
- ccid3_li_hist = dccp_li_hist_new("ccid3");
- if (ccid3_li_hist == NULL)
- goto out_free_tx;
-
rc = ccid_register(&ccid3);
if (rc != 0)
- goto out_free_loss_interval_history;
+ tfrc_tx_cache_cleanup(ccid3_tx_hist);
out:
return rc;
-
-out_free_loss_interval_history:
- dccp_li_hist_delete(ccid3_li_hist);
- ccid3_li_hist = NULL;
-out_free_tx:
- tfrc_tx_cache_cleanup(ccid3_tx_hist);
- goto out;
}
module_init(ccid3_module_init);
@@ -1026,11 +1012,6 @@ static __exit void ccid3_module_exit(voi
if (ccid3_tx_hist != NULL)
tfrc_tx_cache_cleanup(ccid3_tx_hist);
-
- if (ccid3_li_hist != NULL) {
- dccp_li_hist_delete(ccid3_li_hist);
- ccid3_li_hist = NULL;
- }
}
module_exit(ccid3_module_exit);
-
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