diff options
Diffstat (limited to 'src/vnet/session')
| -rw-r--r-- | src/vnet/session/segment_manager.c | 173 | ||||
| -rw-r--r-- | src/vnet/session/segment_manager.h | 16 |
2 files changed, 119 insertions, 70 deletions
diff --git a/src/vnet/session/segment_manager.c b/src/vnet/session/segment_manager.c index 184d3fd597d..cbf6207060c 100644 --- a/src/vnet/session/segment_manager.c +++ b/src/vnet/session/segment_manager.c @@ -89,7 +89,7 @@ segment_manager_segment_index (segment_manager_t * sm, fifo_segment_t * seg) */ static inline int segment_manager_add_segment_inline (segment_manager_t *sm, uword segment_size, - u8 notify_app, u8 flags) + u8 notify_app, u8 flags, u8 need_lock) { segment_manager_main_t *smm = &sm_main; segment_manager_props_t *props; @@ -112,7 +112,7 @@ segment_manager_add_segment_inline (segment_manager_t *sm, uword segment_size, /* * Allocate fifo segment and grab lock if needed */ - if (vlib_num_workers ()) + if (need_lock) clib_rwlock_writer_lock (&sm->segments_rwlock); pool_get_zero (sm->segments, fs); @@ -179,7 +179,7 @@ segment_manager_add_segment_inline (segment_manager_t *sm, uword segment_size, } done: - if (vlib_num_workers ()) + if (need_lock) clib_rwlock_writer_unlock (&sm->segments_rwlock); return fs_index; @@ -189,14 +189,16 @@ int segment_manager_add_segment (segment_manager_t *sm, uword segment_size, u8 notify_app) { - return segment_manager_add_segment_inline (sm, segment_size, notify_app, 0); + return segment_manager_add_segment_inline (sm, segment_size, notify_app, + 0 /* flags */, 0 /* need_lock */); } int segment_manager_add_segment2 (segment_manager_t *sm, uword segment_size, u8 flags) { - return segment_manager_add_segment_inline (sm, segment_size, 0, flags); + return segment_manager_add_segment_inline (sm, segment_size, 0, flags, + vlib_num_workers ()); } /** @@ -333,12 +335,6 @@ segment_manager_segment_reader_unlock (segment_manager_t * sm) clib_rwlock_reader_unlock (&sm->segments_rwlock); } -void -segment_manager_segment_writer_unlock (segment_manager_t * sm) -{ - clib_rwlock_writer_unlock (&sm->segments_rwlock); -} - segment_manager_t * segment_manager_alloc (void) { @@ -740,92 +736,131 @@ segment_manager_try_alloc_fifos (fifo_segment_t * fifo_segment, return 0; } +static inline int +sm_lookup_segment_and_alloc_fifos (segment_manager_t *sm, + segment_manager_props_t *props, + u32 thread_index, svm_fifo_t **rx_fifo, + svm_fifo_t **tx_fifo) +{ + uword free_bytes, max_free_bytes; + fifo_segment_t *cur, *fs = 0; + u32 fs_index; + int rv; + + max_free_bytes = props->rx_fifo_size + props->tx_fifo_size - 1; + + pool_foreach (cur, sm->segments) + { + if (fifo_segment_flags (cur) & FIFO_SEGMENT_F_CUSTOM_USE) + continue; + free_bytes = fifo_segment_available_bytes (cur); + if (free_bytes > max_free_bytes) + { + max_free_bytes = free_bytes; + fs = cur; + } + } + + if (PREDICT_FALSE (!fs)) + return SESSION_E_SEG_NO_SPACE; + + fs_index = segment_manager_segment_index (sm, fs); + rv = segment_manager_try_alloc_fifos (fs, thread_index, props->rx_fifo_size, + props->tx_fifo_size, rx_fifo, tx_fifo); + + return rv ? SESSION_E_SEG_NO_SPACE : fs_index; +} + +static int +sm_lock_and_alloc_segment_and_fifos (segment_manager_t *sm, + segment_manager_props_t *props, + u32 thread_index, svm_fifo_t **rx_fifo, + svm_fifo_t **tx_fifo) +{ + int new_fs_index, rv; + fifo_segment_t *fs; + + if (!props->add_segment) + return SESSION_E_SEG_NO_SPACE; + + clib_rwlock_writer_lock (&sm->segments_rwlock); + + /* Make sure there really is no free space. Another worker might've freed + * some fifos or allocated a segment */ + rv = sm_lookup_segment_and_alloc_fifos (sm, props, thread_index, rx_fifo, + tx_fifo); + if (rv > 0) + goto done; + + new_fs_index = + segment_manager_add_segment (sm, 0 /* segment_size*/, 1 /* notify_app */); + if (new_fs_index < 0) + { + rv = SESSION_E_SEG_CREATE; + goto done; + } + fs = segment_manager_get_segment (sm, new_fs_index); + rv = segment_manager_try_alloc_fifos (fs, thread_index, props->rx_fifo_size, + props->tx_fifo_size, rx_fifo, tx_fifo); + if (rv) + { + clib_warning ("Added a segment, still can't allocate a fifo"); + rv = SESSION_E_SEG_NO_SPACE2; + goto done; + } + + rv = new_fs_index; + +done: + + clib_rwlock_writer_unlock (&sm->segments_rwlock); + + return rv; +} + int segment_manager_alloc_session_fifos (segment_manager_t * sm, u32 thread_index, svm_fifo_t ** rx_fifo, svm_fifo_t ** tx_fifo) { - int alloc_fail = 1, rv = 0, new_fs_index; - uword free_bytes, max_free_bytes = 0; segment_manager_props_t *props; - fifo_segment_t *fs = 0, *cur; - u32 sm_index, fs_index; + u32 sm_index; + int fs_index; props = segment_manager_properties_get (sm); + sm_index = segment_manager_index (sm); /* - * Find the first free segment to allocate the fifos in + * Fast path: find the first segment with enough free space and + * try to allocate the fifos. Done with reader lock */ segment_manager_segment_reader_lock (sm); - pool_foreach (cur, sm->segments) { - if (fifo_segment_flags (cur) & FIFO_SEGMENT_F_CUSTOM_USE) - continue; - free_bytes = fifo_segment_available_bytes (cur); - if (free_bytes > max_free_bytes) - { - max_free_bytes = free_bytes; - fs = cur; - } - } - - if (fs) - { - alloc_fail = segment_manager_try_alloc_fifos (fs, thread_index, - props->rx_fifo_size, - props->tx_fifo_size, - rx_fifo, tx_fifo); - /* On success, keep lock until fifos are initialized */ - if (!alloc_fail) - goto alloc_success; - } + fs_index = sm_lookup_segment_and_alloc_fifos (sm, props, thread_index, + rx_fifo, tx_fifo); segment_manager_segment_reader_unlock (sm); /* - * Allocation failed, see if we can add a new segment + * Slow path: if no fifo segment or alloc fail grab writer lock and try + * to allocate new segment */ - if (props->add_segment) + if (PREDICT_FALSE (fs_index < 0)) { - if ((new_fs_index = segment_manager_add_segment (sm, 0, 1)) < 0) - { - clib_warning ("Failed to add new segment"); - return SESSION_E_SEG_CREATE; - } - fs = segment_manager_get_segment_w_lock (sm, new_fs_index); - alloc_fail = segment_manager_try_alloc_fifos (fs, thread_index, - props->rx_fifo_size, - props->tx_fifo_size, - rx_fifo, tx_fifo); - if (alloc_fail) - { - clib_warning ("Added a segment, still can't allocate a fifo"); - segment_manager_segment_reader_unlock (sm); - return SESSION_E_SEG_NO_SPACE2; - } + fs_index = sm_lock_and_alloc_segment_and_fifos (sm, props, thread_index, + rx_fifo, tx_fifo); + if (fs_index < 0) + return fs_index; } - else - { - SESSION_DBG ("Can't add new seg and no space to allocate fifos!"); - return SESSION_E_SEG_NO_SPACE; - } - -alloc_success: - ASSERT (rx_fifo && tx_fifo); - sm_index = segment_manager_index (sm); - fs_index = segment_manager_segment_index (sm, fs); (*tx_fifo)->segment_manager = sm_index; (*rx_fifo)->segment_manager = sm_index; (*tx_fifo)->segment_index = fs_index; (*rx_fifo)->segment_index = fs_index; - /* Drop the lock after app is notified */ - segment_manager_segment_reader_unlock (sm); - - return rv; + return 0; } void diff --git a/src/vnet/session/segment_manager.h b/src/vnet/session/segment_manager.h index 5a3d772ff02..8b722a02324 100644 --- a/src/vnet/session/segment_manager.h +++ b/src/vnet/session/segment_manager.h @@ -102,8 +102,23 @@ segment_manager_t *segment_manager_get (u32 index); segment_manager_t *segment_manager_get_if_valid (u32 index); u32 segment_manager_index (segment_manager_t * sm); +/** + * Add segment without lock + * + * @param sm Segment manager + * @param segment_size Size of segment to be added + * @param notify_app Flag set if app notification requested + */ int segment_manager_add_segment (segment_manager_t *sm, uword segment_size, u8 notify_app); + +/** + * Add segment with lock + * + * @param sm Segment manager + * @param segment_size Size of segment to be added + * @param flags Flags to be set on segment + */ int segment_manager_add_segment2 (segment_manager_t *sm, uword segment_size, u8 flags); void segment_manager_del_segment (segment_manager_t * sm, @@ -122,7 +137,6 @@ u64 segment_manager_make_segment_handle (u32 segment_manager_index, u64 segment_manager_segment_handle (segment_manager_t * sm, fifo_segment_t * segment); void segment_manager_segment_reader_unlock (segment_manager_t * sm); -void segment_manager_segment_writer_unlock (segment_manager_t * sm); int segment_manager_alloc_session_fifos (segment_manager_t * sm, u32 thread_index, |