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git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs.git
synced 2026-10-30 22:03:17 +01:00
fangqiurong
9ec7ba20c9
Add a scheduler whose ops.dequeue() iterates the source user DSQ with bpf_iter_scx_dsq. The iteration takes the DSQ's raw spinlock; on a kernel that runs ops.dequeue() while the consume path still holds that lock, the first task consumed self-deadlocks the CPU with IRQs disabled. The watchdog cannot recover from that state, so on an unfixed kernel this test wedges the system instead of failing cleanly. On a fixed kernel the scheduler runs clean and the test passes. Signed-off-by: fangqiurong <[email protected]> Signed-off-by: Tejun Heo <[email protected]>
80 lines
1.7 KiB
C
80 lines
1.7 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (c) 2026 fangqiurong <[email protected]>
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*/
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#include <bpf/bpf.h>
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#include <scx/common.h>
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#include <time.h>
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#include <unistd.h>
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#include "dequeue_iter.bpf.skel.h"
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#include "scx_test.h"
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#define DQ_TARGET 10
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#define DQ_DEADLINE_MS 3000
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static unsigned long long now_ms(void)
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{
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struct timespec ts;
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clock_gettime(CLOCK_MONOTONIC, &ts);
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return ts.tv_sec * 1000ULL + ts.tv_nsec / 1000000;
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}
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static enum scx_test_status setup(void **ctx)
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{
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struct dequeue_iter *skel;
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skel = dequeue_iter__open();
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SCX_FAIL_IF(!skel, "Failed to open");
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SCX_ENUM_INIT(skel);
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SCX_FAIL_IF(dequeue_iter__load(skel), "Failed to load skel");
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*ctx = skel;
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return SCX_TEST_PASS;
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}
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static enum scx_test_status run(void *ctx)
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{
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struct dequeue_iter *skel = ctx;
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struct bpf_link *link;
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unsigned long long end;
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link = bpf_map__attach_struct_ops(skel->maps.dequeue_iter_ops);
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SCX_FAIL_IF(!link, "Failed to attach scheduler");
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end = now_ms() + DQ_DEADLINE_MS;
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while (skel->bss->dq_count < DQ_TARGET && !UEI_EXITED(skel, uei) &&
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now_ms() < end)
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usleep(100);
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bpf_link__destroy(link);
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SCX_EQ(skel->data->uei.kind, EXIT_KIND(SCX_EXIT_UNREG));
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if (skel->bss->dq_count < DQ_TARGET) {
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SCX_ERR("ops.dequeue() fired only %llu times",
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(unsigned long long)skel->bss->dq_count);
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return SCX_TEST_FAIL;
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}
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return SCX_TEST_PASS;
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}
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static void cleanup(void *ctx)
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{
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struct dequeue_iter *skel = ctx;
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dequeue_iter__destroy(skel);
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}
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struct scx_test dequeue_iter = {
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.name = "dequeue_iter",
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.description = "Verify ops.dequeue() can iterate its source user DSQ",
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.setup = setup,
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.run = run,
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.cleanup = cleanup,
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};
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REGISTER_SCX_TEST(&dequeue_iter)
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