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| author |   Dave Barach <dave@barachs.net> | 2020-04-09 17:24:07 -0400 |
|---|---|---|
| committer |   Florin Coras <florin.coras@gmail.com> | 2020-04-13 15:54:31 +0000 |
| commit | c74b43c80789f5e437dfe4cc491157b45a7f222e (patch) | |
| tree | 0d149b8147d8225b5a872e709c6845476575fd1f /src/vlib/buffer.c | |
| parent | c54162981cdd41d65ed283df36955007552ddffe (diff) | |
buffers: configurable buffer fault injector
When configured at compile time via the cmake
VPP_BUFFER_FAULT_INJECTOR option, the buffer allocator will appear to
fail a certain fraction of the time.
By default, the allocator succeeds 80% of the time. Detailed command
line configuration options are available, but only when the image has
been compiled with cmake option described above:
vlib { buffer-alloc-success-rate [0.0 ... 1.0]
buffer-alloc-success-seed <nnnn> }
Modify vlib_buffer_pool_create(...) so 0 is always an invalid buffer
index.
Debug images: add checks for bad buffer index enqueues, and also
verify that f->n_vectors doesn't accidentally map one or more
instances of the frame poison pattern 0xfefefefe.
Type: improvement
Signed-off-by: Dave Barach <dave@barachs.net>
Change-Id: Iab939858014463d1e664682805013d334d6fcbe5
Diffstat (limited to 'src/vlib/buffer.c')
| -rw-r--r-- | src/vlib/buffer.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/src/vlib/buffer.c b/src/vlib/buffer.c index 43b1dd63761..f5b813793a3 100644 --- a/src/vlib/buffer.c +++ b/src/vlib/buffer.c @@ -578,6 +578,14 @@ vlib_buffer_pool_create (vlib_main_t * vm, char *name, u32 data_size, p = m->base + (j << m->log2_page_size) + i * alloc_size; p += bm->ext_hdr_size; + /* + * Waste 1 buffer (maximum) so that 0 is never a valid buffer index. + * Allows various places to ASSERT (bi != 0). Much easier + * than debugging downstream crashes in successor nodes. + */ + if (p == m->base) + continue; + vlib_buffer_copy_template ((vlib_buffer_t *) p, &bp->buffer_template); bi = vlib_get_buffer_index (vm, (vlib_buffer_t *) p); @@ -923,6 +931,24 @@ vlib_buffers_configure (vlib_main_t * vm, unformat_input_t * input) VLIB_EARLY_CONFIG_FUNCTION (vlib_buffers_configure, "buffers"); +#if VLIB_BUFFER_ALLOC_FAULT_INJECTOR > 0 +u32 +vlib_buffer_alloc_may_fail (vlib_main_t * vm, u32 n_buffers) +{ + f64 r; + + r = random_f64 (&vm->buffer_alloc_success_seed); + + /* Fail this request? */ + if (r > vm->buffer_alloc_success_rate) + n_buffers--; + /* 5% chance of returning nothing at all */ + if (r > vm->buffer_alloc_success_rate && r > 0.95) + n_buffers = 0; + + return n_buffers; +} +#endif /** @endcond */ /* |