From 8e1ee18c332e08bee9d8bd66e63cd564fbf17fc2 Mon Sep 17 00:00:00 2001 From: Vlad Yasevich Date: Wed, 8 Oct 2008 14:18:39 -0700 Subject: sctp: Rework the tsn map to use generic bitmap. The tsn map currently use is 4K large and is stuck inside the sctp_association structure making memory references REALLY expensive. What we really need is at most 4K worth of bits so the biggest map we would have is 512 bytes. Also, the map is only really usefull when we have gaps to store and report. As such, starting with minimal map of say 32 TSNs (bits) should be enough for normal low-loss operations. We can grow the map by some multiple of 32 along with some extra room any time we receive the TSN which would put us outside of the map boundry. As we close gaps, we can shift the map to rebase it on the latest TSN we've seen. This saves 4088 bytes per association just in the map alone along savings from the now unnecessary structure members. Signed-off-by: Vlad Yasevich Signed-off-by: David S. Miller --- include/net/sctp/tsnmap.h | 39 +++++++++------------------------------ 1 file changed, 9 insertions(+), 30 deletions(-) (limited to 'include/net/sctp/tsnmap.h') diff --git a/include/net/sctp/tsnmap.h b/include/net/sctp/tsnmap.h index 099211bf998d..6dabbee8bbd3 100644 --- a/include/net/sctp/tsnmap.h +++ b/include/net/sctp/tsnmap.h @@ -60,18 +60,7 @@ struct sctp_tsnmap { * It points at one of the two buffers with which we will * ping-pong between. */ - __u8 *tsn_map; - - /* This marks the tsn which overflows the tsn_map, when the - * cumulative ack point reaches this point we know we can switch - * maps (tsn_map and overflow_map swap). - */ - __u32 overflow_tsn; - - /* This is the overflow array for tsn_map. - * It points at one of the other ping-pong buffers. - */ - __u8 *overflow_map; + unsigned long *tsn_map; /* This is the TSN at tsn_map[0]. */ __u32 base_tsn; @@ -89,15 +78,15 @@ struct sctp_tsnmap { */ __u32 cumulative_tsn_ack_point; + /* This is the highest TSN we've marked. */ + __u32 max_tsn_seen; + /* This is the minimum number of TSNs we can track. This corresponds * to the size of tsn_map. Note: the overflow_map allows us to * potentially track more than this quantity. */ __u16 len; - /* This is the highest TSN we've marked. */ - __u32 max_tsn_seen; - /* Data chunks pending receipt. used by SCTP_STATUS sockopt */ __u16 pending_data; @@ -110,24 +99,17 @@ struct sctp_tsnmap { /* Record gap ack block information here. */ struct sctp_gap_ack_block gabs[SCTP_MAX_GABS]; - - int malloced; - - __u8 raw_map[0]; }; struct sctp_tsnmap_iter { __u32 start; }; -/* This macro assists in creation of external storage for variable length - * internal buffers. We double allocate so the overflow map works. - */ -#define sctp_tsnmap_storage_size(count) (sizeof(__u8) * (count) * 2) - /* Initialize a block of memory as a tsnmap. */ struct sctp_tsnmap *sctp_tsnmap_init(struct sctp_tsnmap *, __u16 len, - __u32 initial_tsn); + __u32 initial_tsn, gfp_t gfp); + +void sctp_tsnmap_free(struct sctp_tsnmap *map); /* Test the tracking state of this TSN. * Returns: @@ -138,7 +120,7 @@ struct sctp_tsnmap *sctp_tsnmap_init(struct sctp_tsnmap *, __u16 len, int sctp_tsnmap_check(const struct sctp_tsnmap *, __u32 tsn); /* Mark this TSN as seen. */ -void sctp_tsnmap_mark(struct sctp_tsnmap *, __u32 tsn); +int sctp_tsnmap_mark(struct sctp_tsnmap *, __u32 tsn); /* Mark this TSN and all lower as seen. */ void sctp_tsnmap_skip(struct sctp_tsnmap *map, __u32 tsn); @@ -183,10 +165,7 @@ static inline struct sctp_gap_ack_block *sctp_tsnmap_get_gabs(struct sctp_tsnmap /* Is there a gap in the TSN map? */ static inline int sctp_tsnmap_has_gap(const struct sctp_tsnmap *map) { - int has_gap; - - has_gap = (map->cumulative_tsn_ack_point != map->max_tsn_seen); - return has_gap; + return (map->cumulative_tsn_ack_point != map->max_tsn_seen); } /* Mark a duplicate TSN. Note: limit the storage of duplicate TSN -- cgit v1.2.3 From 02015180e2509afd2e3fe3790a333b30708a116b Mon Sep 17 00:00:00 2001 From: Vlad Yasevich Date: Wed, 8 Oct 2008 14:19:01 -0700 Subject: sctp: shrink sctp_tsnmap some more by removing gabs array The gabs array in the sctp_tsnmap structure is only used in one place, sctp_make_sack(). As such, carrying the array around in the sctp_tsnmap and thus directly in the sctp_association is rather pointless since most of the time it's just taking up space. Now, let sctp_make_sack create and populate it and then throw it away when it's done. Signed-off-by: Vlad Yasevich Signed-off-by: David S. Miller --- include/net/sctp/tsnmap.h | 14 +++----------- net/sctp/sm_make_chunk.c | 6 ++++-- net/sctp/tsnmap.c | 15 ++++++++------- 3 files changed, 15 insertions(+), 20 deletions(-) (limited to 'include/net/sctp/tsnmap.h') diff --git a/include/net/sctp/tsnmap.h b/include/net/sctp/tsnmap.h index 6dabbee8bbd3..4aabc5a96cf6 100644 --- a/include/net/sctp/tsnmap.h +++ b/include/net/sctp/tsnmap.h @@ -94,11 +94,8 @@ struct sctp_tsnmap { * every SACK. Store up to SCTP_MAX_DUP_TSNS worth of * information. */ - __be32 dup_tsns[SCTP_MAX_DUP_TSNS]; __u16 num_dup_tsns; - - /* Record gap ack block information here. */ - struct sctp_gap_ack_block gabs[SCTP_MAX_GABS]; + __be32 dup_tsns[SCTP_MAX_DUP_TSNS]; }; struct sctp_tsnmap_iter { @@ -151,17 +148,12 @@ static inline __be32 *sctp_tsnmap_get_dups(struct sctp_tsnmap *map) } /* How many gap ack blocks do we have recorded? */ -__u16 sctp_tsnmap_num_gabs(struct sctp_tsnmap *map); +__u16 sctp_tsnmap_num_gabs(struct sctp_tsnmap *map, + struct sctp_gap_ack_block *gabs); /* Refresh the count on pending data. */ __u16 sctp_tsnmap_pending(struct sctp_tsnmap *map); -/* Return pointer to gap ack blocks as needed by SACK. */ -static inline struct sctp_gap_ack_block *sctp_tsnmap_get_gabs(struct sctp_tsnmap *map) -{ - return map->gabs; -} - /* Is there a gap in the TSN map? */ static inline int sctp_tsnmap_has_gap(const struct sctp_tsnmap *map) { diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c index 6dd9b3ef33d0..fd8acb48c3f2 100644 --- a/net/sctp/sm_make_chunk.c +++ b/net/sctp/sm_make_chunk.c @@ -702,12 +702,14 @@ struct sctp_chunk *sctp_make_sack(const struct sctp_association *asoc) __u32 ctsn; __u16 num_gabs, num_dup_tsns; struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map; + struct sctp_gap_ack_block gabs[SCTP_MAX_GABS]; + memset(gabs, 0, sizeof(gabs)); ctsn = sctp_tsnmap_get_ctsn(map); SCTP_DEBUG_PRINTK("sackCTSNAck sent: 0x%x.\n", ctsn); /* How much room is needed in the chunk? */ - num_gabs = sctp_tsnmap_num_gabs(map); + num_gabs = sctp_tsnmap_num_gabs(map, gabs); num_dup_tsns = sctp_tsnmap_num_dups(map); /* Initialize the SACK header. */ @@ -763,7 +765,7 @@ struct sctp_chunk *sctp_make_sack(const struct sctp_association *asoc) /* Add the gap ack block information. */ if (num_gabs) sctp_addto_chunk(retval, sizeof(__u32) * num_gabs, - sctp_tsnmap_get_gabs(map)); + gabs); /* Add the duplicate TSN information. */ if (num_dup_tsns) diff --git a/net/sctp/tsnmap.c b/net/sctp/tsnmap.c index 142ed7ca424d..35c73e82553a 100644 --- a/net/sctp/tsnmap.c +++ b/net/sctp/tsnmap.c @@ -335,10 +335,11 @@ void sctp_tsnmap_renege(struct sctp_tsnmap *map, __u32 tsn) } /* How many gap ack blocks do we have recorded? */ -__u16 sctp_tsnmap_num_gabs(struct sctp_tsnmap *map) +__u16 sctp_tsnmap_num_gabs(struct sctp_tsnmap *map, + struct sctp_gap_ack_block *gabs) { struct sctp_tsnmap_iter iter; - int gabs = 0; + int ngaps = 0; /* Refresh the gap ack information. */ if (sctp_tsnmap_has_gap(map)) { @@ -348,14 +349,14 @@ __u16 sctp_tsnmap_num_gabs(struct sctp_tsnmap *map) &start, &end)) { - map->gabs[gabs].start = htons(start); - map->gabs[gabs].end = htons(end); - gabs++; - if (gabs >= SCTP_MAX_GABS) + gabs[ngaps].start = htons(start); + gabs[ngaps].end = htons(end); + ngaps++; + if (ngaps >= SCTP_MAX_GABS) break; } } - return gabs; + return ngaps; } static int sctp_tsnmap_grow(struct sctp_tsnmap *map, u16 gap) -- cgit v1.2.3