Skip to content

fuse: Fix the reduced queue assignment #85

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
bsbernd merged 1 commit into from
Feb 4, 2026
Merged

fuse: Fix the reduced queue assignment #85

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
27 changes: 13 additions & 14 deletions fs/fuse/dev_uring.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -406,26 +406,25 @@ static struct fuse_ring *fuse_uring_create(struct fuse_conn *fc)
}

static void fuse_uring_cpu_qid_mapping(struct fuse_ring *ring, int qid,
struct fuse_queue_map *q_map)
struct fuse_queue_map *q_map,
int node)
{
int cpu, qid_idx;
int cpu, qid_idx, mapping_count = 0;
size_t nr_queues;

cpumask_set_cpu(qid, q_map->registered_q_mask);
nr_queues = cpumask_weight(q_map->registered_q_mask);
for (cpu = 0; cpu < ring->max_nr_queues; cpu++) {
if (!q_map->cpu_to_qid)
return;

/*
* Position of this CPU within the registered queue mask,
* handles non-contiguous CPU distributions across NUMA nodes.
*/
qid_idx = bitmap_weight(
cpumask_bits(q_map->registered_q_mask), cpu);
if (node != -1 && cpu_to_node(cpu) != node)
continue;

q_map->cpu_to_qid[cpu] = cpumask_nth(qid_idx % nr_queues,
qid_idx = mapping_count % nr_queues;
q_map->cpu_to_qid[cpu] = cpumask_nth(qid_idx,
q_map->registered_q_mask);
mapping_count++;
pr_debug("%s node=%d qid=%d qid_idx=%d nr_queues=%zu %d->%d\n",
__func__, node, qid, qid_idx, nr_queues, cpu,
q_map->cpu_to_qid[cpu]);
}
}

Expand Down Expand Up @@ -476,7 +475,7 @@ static struct fuse_ring_queue *fuse_uring_create_queue(struct fuse_ring *ring,

/* Static mapping from cpu to per numa queues */
node = cpu_to_node(qid);
fuse_uring_cpu_qid_mapping(ring, qid, &ring->numa_q_map[node]);
fuse_uring_cpu_qid_mapping(ring, qid, &ring->numa_q_map[node], node);

/*
* smp_store_release, as the variable is read without fc->lock and
Expand All @@ -487,7 +486,7 @@ static struct fuse_ring_queue *fuse_uring_create_queue(struct fuse_ring *ring,
ring->numa_q_map[node].nr_queues + 1);

/* global mapping */
fuse_uring_cpu_qid_mapping(ring, qid, &ring->q_map);
fuse_uring_cpu_qid_mapping(ring, qid, &ring->q_map, -1);

spin_unlock(&fc->lock);

Expand Down