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
+2
View File
@@ -1001,6 +1001,8 @@ bool llm_arch_supports_rs_rollback(const llm_arch & arch) {
case LLM_ARCH_QWEN35:
case LLM_ARCH_QWEN35MOE:
case LLM_ARCH_DEEPSEEK4:
case LLM_ARCH_NEMOTRON_H:
case LLM_ARCH_NEMOTRON_H_MOE:
return true;
default:
return false;
+1 -1
View File
@@ -103,7 +103,7 @@ llama_context::llama_context(
cparams.n_rs_seq = params.n_rs_seq;
if (cparams.n_rs_seq > 0 && !llm_arch_supports_rs_rollback(model.arch)) {
LLAMA_LOG_DEBUG("%s: n_rs_seq=%u requested but model arch does not support recurrent partial rollback; clamping to 0\n",
LLAMA_LOG_DEBUG("%s: n_rs_seq=%u requested but model does not support recurrent partial rollback; clamping to 0\n",
__func__, cparams.n_rs_seq);
cparams.n_rs_seq = 0;
}
+1 -1
View File
@@ -1002,7 +1002,7 @@ static bool weight_buft_supported(const llama_hparams & hparams, ggml_tensor * w
ggml_tensor * B = ggml_new_tensor_4d(ctx, GGML_TYPE_F32, d_state, n_group, n_seq_tokens, n_seqs);
ggml_tensor * C = ggml_new_tensor_4d(ctx, GGML_TYPE_F32, d_state, n_group, n_seq_tokens, n_seqs);
ggml_tensor * ids = ggml_new_tensor_1d(ctx, GGML_TYPE_I32, n_seqs);
op_tensor = ggml_ssm_scan(ctx, s, x, dt, w, B, C, ids);
op_tensor = ggml_ssm_scan(ctx, s, x, dt, w, B, C, ids, /*K=*/1);
} break;
case GGML_OP_RWKV_WKV6:
{
+32 -16
View File
@@ -2,6 +2,8 @@
#include "llama-memory-recurrent.h"
#include <algorithm>
llm_build_mamba_base::llm_build_mamba_base(const llm_graph_params & params) : llm_graph_context(params) {}
ggml_tensor * llm_build_mamba_base::build_mamba_layer(llm_graph_input_rs * inp,
@@ -118,7 +120,7 @@ ggml_tensor * llm_build_mamba_base::build_mamba_layer(llm_graph_input_rs * inp,
// Custom operator to optimize the parallel associative scan
// as described in the Annex D of the Mamba paper.
// => {d_inner, n_seq_tokens, n_seqs} and {d_state, d_inner, n_seqs}
return ggml_ssm_scan(ctx, ssm, x, dt, A, B, C, ids);
return ggml_ssm_scan(ctx, ssm, x, dt, A, B, C, ids, /*K=*/1);
};
ggml_tensor * y_ssm = build_rs(inp, ssm_states_all, hparams.n_embd_s(), ubatch.n_seqs, get_ssm_rows);
@@ -153,7 +155,8 @@ ggml_tensor * llm_build_mamba_base::build_mamba2_layer(llm_graph_input_rs * inp,
int il) const {
const auto * mctx_cur = inp->mctx;
const auto kv_head = mctx_cur->get_head();
const auto kv_head = mctx_cur->get_head();
const auto mem_size = mctx_cur->get_size();
const int64_t d_conv = hparams.ssm_d_conv;
const int64_t d_inner = hparams.ssm_d_inner;
@@ -164,6 +167,7 @@ ggml_tensor * llm_build_mamba_base::build_mamba2_layer(llm_graph_input_rs * inp,
const int64_t n_seqs = ubatch.n_seqs;
const int64_t n_seq_tokens = ubatch.n_seq_tokens;
const int64_t K = cparams.n_rs_seq > 0 ? (int64_t) cparams.n_rs_seq + 1 : 1;
GGML_ASSERT(n_seqs != 0);
GGML_ASSERT(ubatch.equal_seqs());
@@ -173,6 +177,7 @@ ggml_tensor * llm_build_mamba_base::build_mamba2_layer(llm_graph_input_rs * inp,
ggml_tensor * conv_states_all = mctx_cur->get_r_l(il);
ggml_tensor * ssm_states_all = mctx_cur->get_s_l(il);
const int64_t state_slots = ssm_states_all->ne[1];
ggml_tensor * conv = build_rs(inp, conv_states_all, hparams.n_embd_r(), n_seqs);
conv = ggml_reshape_3d(ctx0, conv, d_conv - 1, d_inner + 2 * n_group * d_state, n_seqs);
@@ -198,15 +203,19 @@ ggml_tensor * llm_build_mamba_base::build_mamba2_layer(llm_graph_input_rs * inp,
// => {d_conv - 1 + n_seq_tokens, d_inner + 2*n_group*d_state, n_seqs}
ggml_tensor * conv_x = ggml_concat(ctx0, conv, ggml_transpose(ctx0, xBC), 0);
// copy last (d_conv - 1) columns back into the state cache
ggml_tensor * last_conv = ggml_view_3d(ctx0, conv_x, d_conv - 1, d_inner + 2 * n_group * d_state, n_seqs,
conv_x->nb[1], conv_x->nb[2], n_seq_tokens * (conv_x->nb[0]));
const int64_t row_count = (d_conv - 1) * (d_inner + 2 * n_group * d_state);
const size_t row_size = ggml_row_size(conv_states_all->type, row_count);
const int64_t n_written = std::min<int64_t>(n_seq_tokens, K);
ggml_build_forward_expand(gf, ggml_cpy(ctx0, last_conv,
ggml_view_1d(ctx0, conv_states_all,
(d_conv - 1) * (d_inner + 2 * n_group * d_state) * (n_seqs),
kv_head * (d_conv - 1) * (d_inner + 2 * n_group * d_state) *
ggml_element_size(conv_states_all))));
for (int64_t slot = 0; slot < n_written; ++slot) {
ggml_tensor * last_conv = ggml_view_3d(ctx0, conv_x, d_conv - 1, d_inner + 2 * n_group * d_state, n_seqs,
conv_x->nb[1], conv_x->nb[2], (n_seq_tokens - slot) * conv_x->nb[0]);
ggml_build_forward_expand(gf, ggml_cpy(ctx0, last_conv,
ggml_view_2d(ctx0, conv_states_all, row_count, n_seqs,
conv_states_all->nb[1],
((size_t) slot * mem_size + kv_head) * row_size)));
}
// 1D convolution
// The equivalent is to make a self-overlapping view of conv_x
@@ -244,20 +253,27 @@ ggml_tensor * llm_build_mamba_base::build_mamba2_layer(llm_graph_input_rs * inp,
// (this is necessary in order to properly use the states before they are overwritten,
// while avoiding to make unnecessary copies of the states)
auto get_ssm_rows = [&](ggml_context * ctx, ggml_tensor * states, ggml_tensor * ids) {
ggml_tensor * ssm = ggml_reshape_4d(ctx, states, d_state, head_dim, n_head, mctx_cur->get_size());
ggml_tensor * ssm = ggml_reshape_4d(ctx, states, d_state, head_dim, n_head, state_slots);
// TODO: use semistructured matrices to implement state-space duality
// => {d_inner, n_seq_tokens, n_seqs} and {d_state, d_inner, n_seqs}
return ggml_ssm_scan(ctx, ssm, x, dt, A, B, C, ids);
// K > 1 asks the backend to return rollback snapshots in addition to the final state.
return ggml_ssm_scan(ctx, ssm, x, dt, A, B, C, ids, K);
};
ggml_tensor * y_ssm = build_rs(inp, ssm_states_all, hparams.n_embd_s(), ubatch.n_seqs, get_ssm_rows);
const int64_t D = d_state * d_inner;
const int64_t n_written = std::min<int64_t>(n_seq_tokens, K);
const size_t row_size = ggml_row_size(ssm_states_all->type, D);
const size_t y_row_size = ggml_row_size(y_ssm->type, D);
const size_t state_offset = ggml_nelements(x) * ggml_element_size(x);
// store last states
ggml_build_forward_expand(
gf, ggml_cpy(ctx0, ggml_view_1d(ctx0, y_ssm, d_state * d_inner * n_seqs, ggml_nelements(x) * x->nb[0]),
ggml_view_1d(ctx0, ssm_states_all, d_state * d_inner * n_seqs,
kv_head * d_state * d_inner * ggml_element_size(ssm_states_all))));
gf, ggml_cpy(ctx0,
ggml_view_3d(ctx0, y_ssm, D, n_seqs, n_written,
y_row_size, y_row_size * n_seqs, state_offset),
ggml_view_3d(ctx0, ssm_states_all, D, n_seqs, n_written,
ssm_states_all->nb[1], (size_t) mem_size * row_size, kv_head * row_size)));
ggml_tensor * y = ggml_view_4d(ctx0, y_ssm, head_dim, n_head, n_seq_tokens, n_seqs, x->nb[1], n_head * x->nb[1],
n_seq_tokens * n_head * x->nb[1], 0);
+1 -1
View File
@@ -382,7 +382,7 @@ ggml_tensor * llama_model_plamo2::graph::build_plamo2_mamba_layer(llm_graph_inpu
// Custom operator to optimize the parallel associative scan
// as described in the Annex D of the Mamba paper.
// => {d_inner, n_seq_tokens, n_seqs} and {d_state, d_inner, n_seqs}
return ggml_ssm_scan(ctx, ssm, x, dt, A, B, C, ids);
return ggml_ssm_scan(ctx, ssm, x, dt, A, B, C, ids, /*K=*/1);
};
ggml_tensor * y_ssm = build_rs(inp, ssm_states_all, hparams.n_embd_s(), ubatch.n_seqs, get_ssm_rows);