ggml : recurrent state rollback for ggml_ssm_scan (#26623)

* Initial changes for Recurrent state rollback for nemotron for cpu and cuda

* Removing CPU RS rollback. Will enable it in subsequent PRs

* addition of test case

* Removing assert and calling runtime API to check if op is supported

* removing extra API and updating the call sites for K

* replace static cuda detection to runtime fused_op api

* address review comments and fallback when SSM rollback not supprted

* Adding changes for supporting RS-rollback in CPU. Also added test-backend-ops for cpu and cuda

* removing memory manipulation as rs rollback is now supported in CPU

* removing the static probe which is not needed now

* correcting the format

* address review comments

* enabling test for all the backends, unsupported backends will fallback to CPU

* Apply suggestions from code review

Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>

* choose different graph based on the result of fused_ssm_op is supported or not and also handled memory->n_rs_seq >1 case incase of op is not supported

* Support K > 1 in ssm_scan for all backends

* Fix CI Issues

---------

Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>
Co-authored-by: Gaurav Garg <gaugarg@nvidia.com>
This commit is contained in:
lnigam
2026-08-14 17:20:40 +03:00
committed by GitHub
co-authored by Georgi Gerganov Gaurav Garg
parent 4c1a0af40d
commit 1692f9e50b
25 changed files with 291 additions and 43 deletions
+117 -4
View File
@@ -4111,9 +4111,10 @@ struct test_ssm_scan : public test_case {
const int64_t n_seq_tokens;
const int64_t n_seqs;
const bool xbc_overlap;
const int64_t K;
std::string vars() override {
return VARS_TO_STR8(type, d_state, head_dim, n_head, n_group, n_seq_tokens, n_seqs, xbc_overlap);
return VARS_TO_STR9(type, d_state, head_dim, n_head, n_group, n_seq_tokens, n_seqs, xbc_overlap, K);
}
test_ssm_scan(ggml_type type = GGML_TYPE_F32,
@@ -4123,8 +4124,9 @@ struct test_ssm_scan : public test_case {
int64_t n_group = 1,
int64_t n_seq_tokens = 32,
int64_t n_seqs = 32,
bool xbc_overlap = false)
: type(type), d_state(d_state), head_dim(head_dim), n_head(n_head), n_group(n_group), n_seq_tokens(n_seq_tokens), n_seqs(n_seqs), xbc_overlap(xbc_overlap) {}
bool xbc_overlap = false,
int64_t K = 1)
: type(type), d_state(d_state), head_dim(head_dim), n_head(n_head), n_group(n_group), n_seq_tokens(n_seq_tokens), n_seqs(n_seqs), xbc_overlap(xbc_overlap), K(K) {}
double max_nmse_err() override {
// SSD path (head_dim > 1) uses FP16 intermediates (M matrix, X_dt); Mamba-1 is pure FP32.
@@ -4153,7 +4155,7 @@ struct test_ssm_scan : public test_case {
C = ggml_new_tensor_4d(ctx, type, d_state, n_group, n_seq_tokens, n_seqs);
}
ggml_tensor * ids = ggml_new_tensor_1d(ctx, GGML_TYPE_I32, n_seqs);
ggml_tensor * out = ggml_ssm_scan(ctx, s, x, dt, A, B, C, ids);
ggml_tensor * out = ggml_ssm_scan(ctx, s, x, dt, A, B, C, ids, K);
return out;
}
@@ -4185,6 +4187,114 @@ struct test_ssm_scan : public test_case {
}
};
struct test_ssm_scan_rollback : public test_case {
const ggml_type type;
const int64_t d_state;
const int64_t head_dim;
const int64_t n_head;
const int64_t n_group;
const int64_t n_seq_tokens;
const int64_t n_seqs;
const int64_t K;
std::string vars() override {
return VARS_TO_STR8(type, d_state, head_dim, n_head, n_group, n_seq_tokens, n_seqs, K);
}
std::string op_desc(ggml_tensor * t) override {
GGML_UNUSED(t);
return "SSM_SCAN_ROLLBACK";
}
bool run_whole_graph() override {
return true;
}
double max_err() override {
return 1e-6;
}
double err(const float * a, const float * b, size_t n) override {
double result = 0.0;
for (size_t i = 0; i < n; ++i) {
result = std::max(result, (double) fabsf(a[i]));
result = std::max(result, (double) fabsf(b[i]));
}
return result;
}
test_ssm_scan_rollback(ggml_type type = GGML_TYPE_F32,
int64_t d_state = 32,
int64_t head_dim = 64,
int64_t n_head = 16,
int64_t n_group = 2,
int64_t n_seq_tokens = 8,
int64_t n_seqs = 2,
int64_t K = 3)
: type(type), d_state(d_state), head_dim(head_dim), n_head(n_head), n_group(n_group),
n_seq_tokens(n_seq_tokens), n_seqs(n_seqs), K(K) {}
ggml_tensor * build_graph(ggml_context * ctx) override {
ggml_tensor * s = ggml_new_tensor_4d(ctx, type, d_state, head_dim, n_head, n_seqs);
ggml_tensor * x = ggml_new_tensor_4d(ctx, type, head_dim, n_head, n_seq_tokens, n_seqs);
ggml_tensor * dt = ggml_new_tensor_3d(ctx, type, n_head, n_seq_tokens, n_seqs);
ggml_tensor * A = ggml_new_tensor_2d(ctx, type, 1, n_head);
ggml_tensor * B = ggml_new_tensor_4d(ctx, type, d_state, n_group, n_seq_tokens, n_seqs);
ggml_tensor * C = ggml_new_tensor_4d(ctx, type, d_state, n_group, n_seq_tokens, n_seqs);
ggml_tensor * ids = ggml_new_tensor_1d(ctx, GGML_TYPE_I32, n_seqs);
ggml_tensor * full = ggml_ssm_scan(ctx, s, x, dt, A, B, C, ids, K);
const int64_t y_elems = head_dim * n_head * n_seq_tokens * n_seqs;
const int64_t state_elems = d_state * head_dim * n_head * n_seqs;
ggml_tensor * out = nullptr;
for (int64_t slot = 0; slot < K; ++slot) {
const int64_t prefix_tokens = n_seq_tokens - slot;
ggml_tensor * x_prefix = ggml_cont(ctx, ggml_view_4d(ctx, x, head_dim, n_head, prefix_tokens, n_seqs, x->nb[1], x->nb[2], x->nb[3], 0));
ggml_tensor * dt_prefix = ggml_cont(ctx, ggml_view_3d(ctx, dt, n_head, prefix_tokens, n_seqs, dt->nb[1], dt->nb[2], 0));
ggml_tensor * B_prefix = ggml_cont(ctx, ggml_view_4d(ctx, B, d_state, n_group, prefix_tokens, n_seqs, B->nb[1], B->nb[2], B->nb[3], 0));
ggml_tensor * C_prefix = ggml_cont(ctx, ggml_view_4d(ctx, C, d_state, n_group, prefix_tokens, n_seqs, C->nb[1], C->nb[2], C->nb[3], 0));
ggml_tensor * prefix = ggml_ssm_scan(ctx, s, x_prefix, dt_prefix, A, B_prefix, C_prefix, ids, /*K=*/1);
ggml_tensor * full_state = ggml_view_1d(ctx, full, state_elems, (y_elems + slot*state_elems)*ggml_element_size(full));
ggml_tensor * prefix_state = ggml_view_1d(ctx, prefix, state_elems, (head_dim*n_head*prefix_tokens*n_seqs)*ggml_element_size(prefix));
ggml_tensor * diff = ggml_sum(ctx, ggml_sqr(ctx, ggml_sub(ctx, full_state, prefix_state)));
out = out == nullptr ? diff : ggml_add(ctx, out, diff);
}
return out;
}
void initialize_tensors(ggml_context * ctx) override {
std::random_device rd;
std::default_random_engine rng(rd());
for (ggml_tensor * t = ggml_get_first_tensor(ctx); t != NULL; t = ggml_get_next_tensor(ctx, t)) {
if (t->type == GGML_TYPE_I32) {
if (ggml_is_view_op(t->op)) { continue; }
for (int64_t r = 0; r < ggml_nrows(t); r++) {
std::vector<int32_t> data(t->ne[0]);
for (int i = 0; i < t->ne[0]; i++) {
data[i] = i;
}
std::shuffle(data.begin(), data.end(), rng);
ggml_backend_tensor_set(t, data.data(), r * t->nb[1], t->ne[0] * sizeof(int32_t));
}
} else if (ggml_is_view_op(t->op)) {
continue;
} else if (t->ne[1] == n_head && t->ne[2] == 1) {
init_tensor_uniform(t, -1.0f, -0.5f);
} else {
init_tensor_uniform(t);
}
}
}
};
// GGML_OP_RWKV_WKV6
struct test_rwkv_wkv6 : public test_case {
const ggml_type type;
@@ -8952,6 +9062,9 @@ static std::vector<std::unique_ptr<test_case>> make_test_cases_eval() {
test_cases.emplace_back(new test_ssm_scan(GGML_TYPE_F32, 128, 80, 128, 1, 256, 1)); // Nemotron-9B SSD path
test_cases.emplace_back(new test_ssm_scan(GGML_TYPE_F32, 128, 80, 128, 1, 512, 1)); // Nemotron-9B SSD multi-chunk (2 aligned chunks)
test_cases.emplace_back(new test_ssm_scan(GGML_TYPE_F32, 128, 64, 80, 8, 300, 2)); // Mamba-2 SSD multi-chunk (partial 2nd chunk, 2 seqs)
test_cases.emplace_back(new test_ssm_scan(GGML_TYPE_F32, 128, 64, 16, 2, 4, 2, false, /*K=*/4)); // Mamba-2 rollback snapshots
test_cases.emplace_back(new test_ssm_scan(GGML_TYPE_F32, 128, 64, 16, 2, 8, 2, false, /*K=*/3)); // Mamba-2 rollback overflow
test_cases.emplace_back(new test_ssm_scan_rollback(GGML_TYPE_F32, 128, 64, 16, 2, 8, 2, /*K=*/3)); // rollback snapshots match prefix states
test_cases.emplace_back(new test_rwkv_wkv6(GGML_TYPE_F32, 32, 64, 1, 1));
test_cases.emplace_back(new test_rwkv_wkv6(GGML_TYPE_F32, 32, 64, 32, 1));