Skip to content

ggml webgpu: Move to no timeout for WaitAny in graph submission to avoid deadlocks #20618

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
reeselevine merged 1 commit into from
Mar 18, 2026
Merged

ggml webgpu: Move to no timeout for WaitAny in graph submission to avoid deadlocks #20618

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
60 changes: 24 additions & 36 deletions ggml/src/ggml-webgpu/ggml-webgpu.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -509,50 +509,39 @@ static void ggml_backend_webgpu_wait_profile_futures(webgpu_global_context &
static void ggml_backend_webgpu_wait(webgpu_global_context & ctx,
std::vector<webgpu_submission> & subs,
bool block = true) {
// If we have too many in-flight submissions, wait on the oldest one first.
if (subs.empty()) {
return;
}
while (subs.size() >= WEBGPU_MAX_INFLIGHT_SUBS_PER_THREAD) {
auto waitStatus = ctx->instance.WaitAny(1, &subs[0].submit_done, UINT64_MAX);
if (ggml_backend_webgpu_handle_wait_status(waitStatus)) {

bool blocking_wait = block || subs.size() >= WEBGPU_MAX_INFLIGHT_SUBS_PER_THREAD;
while (blocking_wait) {
auto waitStatus = ctx->instance.WaitAny(1, &subs[0].submit_done, 0);
if (ggml_backend_webgpu_handle_wait_status(waitStatus, true)) {
#ifdef GGML_WEBGPU_GPU_PROFILE
ggml_backend_webgpu_wait_profile_futures(ctx, subs[0].profile_futures, true);
#endif
subs.erase(subs.begin());
}
blocking_wait = (block && !subs.empty()) || subs.size() >= WEBGPU_MAX_INFLIGHT_SUBS_PER_THREAD;
}

if (subs.empty()) {
return;
}

if (block) {
for (auto & sub : subs) {
while (!sub.submit_done.completed) {
auto waitStatus = ctx->instance.WaitAny(1, &sub.submit_done, UINT64_MAX);
ggml_backend_webgpu_handle_wait_status(waitStatus);
}
#ifdef GGML_WEBGPU_GPU_PROFILE
ggml_backend_webgpu_wait_profile_futures(ctx, sub.profile_futures, true);
#endif
}
subs.clear();
} else {
// Poll each submit future once and remove completed submissions.
for (auto sub = subs.begin(); sub != subs.end();) {
auto waitStatus = ctx->instance.WaitAny(1, &sub->submit_done, 0);
ggml_backend_webgpu_handle_wait_status(waitStatus, true);
// Poll each submit future once and remove completed submissions.
for (auto sub = subs.begin(); sub != subs.end();) {
auto waitStatus = ctx->instance.WaitAny(1, &sub->submit_done, 0);
bool success = ggml_backend_webgpu_handle_wait_status(waitStatus, true);
#ifdef GGML_WEBGPU_GPU_PROFILE
ggml_backend_webgpu_wait_profile_futures(ctx, sub->profile_futures, false);
if (sub->submit_done.completed && sub->profile_futures.empty()) {
ggml_backend_webgpu_wait_profile_futures(ctx, sub->profile_futures, false);
if (success && sub->profile_futures.empty()) {
#else
if (sub->submit_done.completed) {
if (success) {
#endif
sub = subs.erase(sub);
} else {
++sub;
}
sub = subs.erase(sub);
} else {
++sub;
}
}
}
Expand Down Expand Up @@ -2961,17 +2950,16 @@ static ggml_backend_buffer_type_t ggml_backend_webgpu_device_get_buffer_type(ggm

static struct ggml_backend_buffer_type ggml_backend_webgpu_buffer_type = {
/* .iface = */ {
/* .get_name = */ ggml_backend_webgpu_buffer_type_get_name,
/* .alloc_buffer = */
ggml_backend_webgpu_buffer_type_alloc_buffer, /* .get_alignment = */
ggml_backend_webgpu_buffer_type_get_alignment, /* .get_max_size = */
ggml_backend_webgpu_buffer_type_get_max_size, /* .get_alloc_size = */
ggml_backend_webgpu_buffer_type_get_alloc_size, /* .is_host = */ NULL, // defaults to false
/* .get_name = */ ggml_backend_webgpu_buffer_type_get_name,
/* .alloc_buffer = */ ggml_backend_webgpu_buffer_type_alloc_buffer,
/* .get_alignment = */ ggml_backend_webgpu_buffer_type_get_alignment,
/* .get_max_size = */ ggml_backend_webgpu_buffer_type_get_max_size,
/* .get_alloc_size = */ ggml_backend_webgpu_buffer_type_get_alloc_size,
/* .is_host = */ NULL, // defaults to false
},
/* .device = */
dev,
/* .context = */
NULL
dev,
/* .context = */ NULL
};

return &ggml_backend_webgpu_buffer_type;
Expand Down
Loading