8b14f3abc0
Looking at the thread counts in our services, jemalloc's background thread is useful, but mostly idle. Add a config option to tune down the number of threads.
84 lines
2.7 KiB
C
84 lines
2.7 KiB
C
#include "test/jemalloc_test.h"
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const char *malloc_conf = "background_thread:false,narenas:1,max_background_threads:20";
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TEST_BEGIN(test_deferred) {
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test_skip_if(!have_background_thread);
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unsigned id;
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size_t sz_u = sizeof(unsigned);
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/*
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* 10 here is somewhat arbitrary, except insofar as we want to ensure
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* that the number of background threads is smaller than the number of
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* arenas. I'll ragequit long before we have to spin up 10 threads per
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* cpu to handle background purging, so this is a conservative
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* approximation.
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*/
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for (unsigned i = 0; i < 10 * ncpus; i++) {
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assert_d_eq(mallctl("arenas.create", &id, &sz_u, NULL, 0), 0,
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"Failed to create arena");
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}
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bool enable = true;
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size_t sz_b = sizeof(bool);
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assert_d_eq(mallctl("background_thread", NULL, NULL, &enable, sz_b), 0,
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"Failed to enable background threads");
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enable = false;
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assert_d_eq(mallctl("background_thread", NULL, NULL, &enable, sz_b), 0,
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"Failed to disable background threads");
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}
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TEST_END
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TEST_BEGIN(test_max_background_threads) {
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test_skip_if(!have_background_thread);
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size_t maxt;
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size_t opt_maxt;
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size_t sz_m = sizeof(maxt);
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assert_d_eq(mallctl("opt.max_background_threads",
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&opt_maxt, &sz_m, NULL, 0), 0,
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"Failed to get opt.max_background_threads");
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assert_d_eq(mallctl("max_background_threads", &maxt, &sz_m, NULL, 0), 0,
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"Failed to get max background threads");
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assert_zu_eq(20, maxt, "should be ncpus");
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assert_zu_eq(opt_maxt, maxt,
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"max_background_threads and "
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"opt.max_background_threads should match");
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assert_d_eq(mallctl("max_background_threads", NULL, NULL, &maxt, sz_m),
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0, "Failed to set max background threads");
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unsigned id;
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size_t sz_u = sizeof(unsigned);
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for (unsigned i = 0; i < 10 * ncpus; i++) {
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assert_d_eq(mallctl("arenas.create", &id, &sz_u, NULL, 0), 0,
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"Failed to create arena");
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}
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bool enable = true;
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size_t sz_b = sizeof(bool);
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assert_d_eq(mallctl("background_thread", NULL, NULL, &enable, sz_b), 0,
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"Failed to enable background threads");
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assert_zu_eq(n_background_threads, maxt,
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"Number of background threads should be 3.\n");
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maxt = 10;
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assert_d_eq(mallctl("max_background_threads", NULL, NULL, &maxt, sz_m),
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0, "Failed to set max background threads");
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assert_zu_eq(n_background_threads, maxt,
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"Number of background threads should be 10.\n");
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maxt = 3;
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assert_d_eq(mallctl("max_background_threads", NULL, NULL, &maxt, sz_m),
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0, "Failed to set max background threads");
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assert_zu_eq(n_background_threads, maxt,
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"Number of background threads should be 3.\n");
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}
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TEST_END
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int
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main(void) {
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return test_no_reentrancy(
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test_deferred,
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test_max_background_threads);
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}
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