From 818eb54de01459ed3d823f8a9781bbed0845db82 Mon Sep 17 00:00:00 2001 From: Dave Barach Date: Wed, 2 Aug 2017 13:56:13 -0400 Subject: Improve the svm fifo allocator - Round up requested fifo size to the next power of two - Maintain per-segment power-of-two freelists - Allocate fifos in chunks, to amortize alignment overhead - Detach builtin test client application after each run so we can use different fifo sizes each time - Be more suspicious of session / application indices Useful prep work for dynamically resizing fifos. As far as the svm fifo code is concerned, it's OK to set fifo->nitems anywhere in the interval: [0, 1<<(fifo->freelist_index) + FIFO_SEGMENT_MIN_FIFO_SIZE] It's unlikely that setting nitems below the path MTU will work out very well... Change-Id: Idad73a027dfb7412056cb02988b77e300fa7e8a7 Signed-off-by: Dave Barach --- src/svm/svm_fifo.c | 5 +- src/svm/svm_fifo.h | 3 +- src/svm/svm_fifo_segment.c | 130 ++++++++++++++++++++++++++++++++++++++++----- src/svm/svm_fifo_segment.h | 6 ++- 4 files changed, 127 insertions(+), 17 deletions(-) (limited to 'src/svm') diff --git a/src/svm/svm_fifo.c b/src/svm/svm_fifo.c index e478c06e891..7f8127cfa69 100644 --- a/src/svm/svm_fifo.c +++ b/src/svm/svm_fifo.c @@ -192,8 +192,11 @@ svm_fifo_t * svm_fifo_create (u32 data_size_in_bytes) { svm_fifo_t *f; + u32 rounded_data_size; - f = clib_mem_alloc_aligned_or_null (sizeof (*f) + data_size_in_bytes, + /* always round fifo data size to the next highest power-of-two */ + rounded_data_size = (1 << (max_log2 (data_size_in_bytes))); + f = clib_mem_alloc_aligned_or_null (sizeof (*f) + rounded_data_size, CLIB_CACHE_LINE_BYTES); if (f == 0) return 0; diff --git a/src/svm/svm_fifo.h b/src/svm/svm_fifo.h index f10b4d91a2a..84901d022d6 100644 --- a/src/svm/svm_fifo.h +++ b/src/svm/svm_fifo.h @@ -75,7 +75,8 @@ typedef struct _svm_fifo #if SVM_FIFO_TRACE svm_fifo_trace_elem_t *trace; #endif - i8 refcnt; + u32 freelist_index; /**< aka log2(allocated_size) - const. */ + i8 refcnt; /**< reference count */ CLIB_CACHE_LINE_ALIGN_MARK (data); } svm_fifo_t; diff --git a/src/svm/svm_fifo_segment.c b/src/svm/svm_fifo_segment.c index c04b9d8ccba..2094ba74a9f 100644 --- a/src/svm/svm_fifo_segment.c +++ b/src/svm/svm_fifo_segment.c @@ -17,13 +17,54 @@ svm_fifo_segment_main_t svm_fifo_segment_main; +static void +allocate_new_fifo_chunk (svm_fifo_segment_header_t * fsh, + u32 data_size_in_bytes, int chunk_size) +{ + int freelist_index; + u32 size; + u8 *fifo_space; + u32 rounded_data_size; + svm_fifo_t *f; + int i; + + rounded_data_size = (1 << (max_log2 (data_size_in_bytes))); + freelist_index = max_log2 (rounded_data_size) + - max_log2 (FIFO_SEGMENT_MIN_FIFO_SIZE); + + /* Calculate space requirement $$$ round-up data_size_in_bytes */ + size = (sizeof (*f) + rounded_data_size) * chunk_size; + + /* Allocate fifo space. May fail. */ + fifo_space = clib_mem_alloc_aligned_at_offset + (size, CLIB_CACHE_LINE_BYTES, 0 /* align_offset */ , + 0 /* os_out_of_memory */ ); + + /* Out of space.. */ + if (fifo_space == 0) + return; + + /* Carve fifo space */ + f = (svm_fifo_t *) fifo_space; + for (i = 0; i < chunk_size; i++) + { + f->freelist_index = freelist_index; + f->next = fsh->free_fifos[freelist_index]; + fsh->free_fifos[freelist_index] = f; + fifo_space += sizeof (*f) + rounded_data_size; + f = (svm_fifo_t *) fifo_space; + } +} + static void preallocate_fifo_pairs (svm_fifo_segment_header_t * fsh, svm_fifo_segment_create_args_t * a) { u32 rx_fifo_size, tx_fifo_size; + u32 rx_rounded_data_size, tx_rounded_data_size; svm_fifo_t *f; u8 *rx_fifo_space, *tx_fifo_space; + int rx_freelist_index, tx_freelist_index; int i; /* Parameter check */ @@ -31,10 +72,39 @@ preallocate_fifo_pairs (svm_fifo_segment_header_t * fsh, || a->preallocated_fifo_pairs == 0) return; - /* Calculate space requirements */ - rx_fifo_size = (sizeof (*f) + a->rx_fifo_size) * a->preallocated_fifo_pairs; - tx_fifo_size = (sizeof (*f) + a->tx_fifo_size) * a->preallocated_fifo_pairs; + if (a->rx_fifo_size < FIFO_SEGMENT_MIN_FIFO_SIZE || + a->rx_fifo_size > FIFO_SEGMENT_MAX_FIFO_SIZE) + { + clib_warning ("rx fifo_size out of range %d", a->rx_fifo_size); + return; + } + + if (a->tx_fifo_size < FIFO_SEGMENT_MIN_FIFO_SIZE || + a->tx_fifo_size > FIFO_SEGMENT_MAX_FIFO_SIZE) + { + clib_warning ("tx fifo_size out of range %d", a->rx_fifo_size); + return; + } + + rx_rounded_data_size = (1 << (max_log2 (a->rx_fifo_size))); + + rx_freelist_index = max_log2 (a->rx_fifo_size) + - max_log2 (FIFO_SEGMENT_MIN_FIFO_SIZE); + + tx_rounded_data_size = (1 << (max_log2 (a->rx_fifo_size))); + + tx_freelist_index = max_log2 (a->tx_fifo_size) + - max_log2 (FIFO_SEGMENT_MIN_FIFO_SIZE); + /* Calculate space requirements */ + rx_fifo_size = (sizeof (*f) + rx_rounded_data_size) + * a->preallocated_fifo_pairs; + tx_fifo_size = (sizeof (*f) + tx_rounded_data_size) + * a->preallocated_fifo_pairs; + + vec_validate_init_empty (fsh->free_fifos, + clib_max (rx_freelist_index, tx_freelist_index), + 0); if (0) clib_warning ("rx_fifo_size %u (%d mb), tx_fifo_size %u (%d mb)", rx_fifo_size, rx_fifo_size >> 20, @@ -71,18 +141,20 @@ preallocate_fifo_pairs (svm_fifo_segment_header_t * fsh, f = (svm_fifo_t *) rx_fifo_space; for (i = 0; i < a->preallocated_fifo_pairs; i++) { - f->next = fsh->free_fifos[FIFO_SEGMENT_RX_FREELIST]; - fsh->free_fifos[FIFO_SEGMENT_RX_FREELIST] = f; - rx_fifo_space += sizeof (*f) + a->rx_fifo_size; + f->freelist_index = rx_freelist_index; + f->next = fsh->free_fifos[rx_freelist_index]; + fsh->free_fifos[rx_freelist_index] = f; + rx_fifo_space += sizeof (*f) + rx_rounded_data_size; f = (svm_fifo_t *) rx_fifo_space; } /* Carve tx fifo space */ f = (svm_fifo_t *) tx_fifo_space; for (i = 0; i < a->preallocated_fifo_pairs; i++) { - f->next = fsh->free_fifos[FIFO_SEGMENT_TX_FREELIST]; - fsh->free_fifos[FIFO_SEGMENT_TX_FREELIST] = f; - tx_fifo_space += sizeof (*f) + a->tx_fifo_size; + f->freelist_index = tx_freelist_index; + f->next = fsh->free_fifos[tx_freelist_index]; + fsh->free_fifos[tx_freelist_index] = f; + tx_fifo_space += sizeof (*f) + tx_rounded_data_size; f = (svm_fifo_t *) tx_fifo_space; } } @@ -277,6 +349,21 @@ svm_fifo_segment_alloc_fifo (svm_fifo_segment_private_t * s, svm_fifo_segment_header_t *fsh; svm_fifo_t *f; void *oldheap; + int freelist_index; + + /* + * 2K minimum. It's not likely that anything good will happen + * with a 1K FIFO. + */ + if (data_size_in_bytes < FIFO_SEGMENT_MIN_FIFO_SIZE || + data_size_in_bytes > FIFO_SEGMENT_MAX_FIFO_SIZE) + { + clib_warning ("fifo size out of range %d", data_size_in_bytes); + return 0; + } + + freelist_index = max_log2 (data_size_in_bytes) + - max_log2 (FIFO_SEGMENT_MIN_FIFO_SIZE); sh = s->ssvm.sh; fsh = (svm_fifo_segment_header_t *) sh->opaque[0]; @@ -288,15 +375,24 @@ svm_fifo_segment_alloc_fifo (svm_fifo_segment_private_t * s, { case FIFO_SEGMENT_RX_FREELIST: case FIFO_SEGMENT_TX_FREELIST: - f = fsh->free_fifos[list_index]; - if (f) + vec_validate_init_empty (fsh->free_fifos, freelist_index, 0); + + f = fsh->free_fifos[freelist_index]; + if (PREDICT_FALSE (f == 0)) { - fsh->free_fifos[list_index] = f->next; + allocate_new_fifo_chunk (fsh, data_size_in_bytes, + FIFO_SEGMENT_ALLOC_CHUNK_SIZE); + f = fsh->free_fifos[freelist_index]; + } + if (PREDICT_TRUE (f != 0)) + { + fsh->free_fifos[freelist_index] = f->next; /* (re)initialize the fifo, as in svm_fifo_create */ memset (f, 0, sizeof (*f)); f->nitems = data_size_in_bytes; f->ooos_list_head = OOO_SEGMENT_INVALID_INDEX; f->refcnt = 1; + f->freelist_index = freelist_index; goto found; } /* FALLTHROUGH */ @@ -316,6 +412,7 @@ svm_fifo_segment_alloc_fifo (svm_fifo_segment_private_t * s, ssvm_unlock_non_recursive (sh); return (0); } + f->freelist_index = freelist_index; found: /* If rx_freelist add to active fifos list. When cleaning up segment, @@ -344,6 +441,7 @@ svm_fifo_segment_free_fifo (svm_fifo_segment_private_t * s, svm_fifo_t * f, ssvm_shared_header_t *sh; svm_fifo_segment_header_t *fsh; void *oldheap; + int freelist_index; ASSERT (f->refcnt > 0); @@ -353,6 +451,10 @@ svm_fifo_segment_free_fifo (svm_fifo_segment_private_t * s, svm_fifo_t * f, sh = s->ssvm.sh; fsh = (svm_fifo_segment_header_t *) sh->opaque[0]; + freelist_index = f->freelist_index; + + ASSERT (freelist_index > 0 && freelist_index < vec_len (fsh->free_fifos)); + ssvm_lock_non_recursive (sh, 2); oldheap = ssvm_push_heap (sh); @@ -369,9 +471,9 @@ svm_fifo_segment_free_fifo (svm_fifo_segment_private_t * s, svm_fifo_t * f, /* Fall through: we add only rx fifos to active pool */ case FIFO_SEGMENT_TX_FREELIST: /* Add to free list */ - f->next = fsh->free_fifos[list_index]; + f->next = fsh->free_fifos[freelist_index]; f->prev = 0; - fsh->free_fifos[list_index] = f; + fsh->free_fifos[freelist_index] = f; break; case FIFO_SEGMENT_FREELIST_NONE: break; diff --git a/src/svm/svm_fifo_segment.h b/src/svm/svm_fifo_segment.h index a7a3f469bab..68bb4d3d57d 100644 --- a/src/svm/svm_fifo_segment.h +++ b/src/svm/svm_fifo_segment.h @@ -27,11 +27,15 @@ typedef enum FIFO_SEGMENT_N_FREELISTS } svm_fifo_segment_freelist_t; +#define FIFO_SEGMENT_MIN_FIFO_SIZE 2048 +#define FIFO_SEGMENT_MAX_FIFO_SIZE (8<<20) /* 8mb max fifo size */ +#define FIFO_SEGMENT_ALLOC_CHUNK_SIZE 32 /* allocation quantum */ + typedef struct { svm_fifo_t *fifos; /**< Linked list of active RX fifos */ u8 *segment_name; /**< Segment name */ - svm_fifo_t *free_fifos[FIFO_SEGMENT_N_FREELISTS]; /**< Free lists */ + svm_fifo_t **free_fifos; /**< Freelists, by fifo size */ } svm_fifo_segment_header_t; typedef struct -- cgit 1.2.3-korg