diff options
author | Frank Ch. Eigler <fche@redhat.com> | 2023-01-10 17:59:35 -0500 |
---|---|---|
committer | Frank Ch. Eigler <fche@redhat.com> | 2023-01-10 17:59:35 -0500 |
commit | 7399e3bd7eb72d045b479173be985803f389f776 (patch) | |
tree | 7c34f0e96f8b234de67ec538bebef6c6cffd0644 | |
parent | a5b07cdf9c491fb7a4a16598c482c68b718f59b9 (diff) | |
download | elfutils-users/fche/try-lessC.tar.gz |
debuginfod PR29975 & PR29976: decrease default concurrencyusers/fche/try-lessC
... based on rlimit (rlimig -n NUM)
... based on cpu-affinity (taskset -c A,B,C,D ...)
-rw-r--r-- | configure.ac | 6 | ||||
-rw-r--r-- | debuginfod/debuginfod.cxx | 59 |
2 files changed, 63 insertions, 2 deletions
diff --git a/configure.ac b/configure.ac index b2597f8b..8fe8baee 100644 --- a/configure.ac +++ b/configure.ac @@ -455,6 +455,12 @@ AS_IF([test "x$ac_cv_func_mremap" = "xno"], AC_CHECK_HEADERS([error.h]) AC_CHECK_HEADERS([err.h]) +dnl for debuginfod concurrency heuristics +AC_CHECK_HEADERS([sched.h]) +AC_CHECK_FUNCS([sched_getaffinity]) +AC_CHECK_HEADERS([sys/resource.h]) +AC_CHECK_FUNCS([getrlimit]) + old_CFLAGS="$CFLAGS" CFLAGS="$CFLAGS -D_GNU_SOURCE" AC_FUNC_STRERROR_R() diff --git a/debuginfod/debuginfod.cxx b/debuginfod/debuginfod.cxx index 02a11477..4271acf4 100644 --- a/debuginfod/debuginfod.cxx +++ b/debuginfod/debuginfod.cxx @@ -32,6 +32,18 @@ #include "config.h" #endif +// #define _GNU_SOURCE +#ifdef HAVE_SCHED_H +extern "C" { +#include <sched.h> +} +#endif +#ifdef HAVE_SYS_RESOURCE_H +extern "C" { +#include <sys/resource.h> +} +#endif + extern "C" { #include "printversion.h" #include "system.h" @@ -398,6 +410,8 @@ static const char args_doc[] = "[PATH ...]"; /* Prototype for option handler. */ static error_t parse_opt (int key, char *arg, struct argp_state *state); +static unsigned default_concurrency(); + /* Data structure to communicate with argp functions. */ static struct argp argp = { @@ -418,7 +432,7 @@ static unsigned http_port = 8002; static unsigned rescan_s = 300; static unsigned groom_s = 86400; static bool maxigroom = false; -static unsigned concurrency = std::thread::hardware_concurrency() ?: 1; +static unsigned concurrency = default_concurrency(); static int connection_pool = 0; static set<string> source_paths; static bool scan_files = false; @@ -4082,6 +4096,47 @@ static void sqlite3_sharedprefix_fn (sqlite3_context* c, int argc, sqlite3_value } +static unsigned +default_concurrency() // guaranteed >= 1 +{ + // Prior to PR29975 & PR29976, we'd just use this: + unsigned sth = std::thread::hardware_concurrency(); + // ... but on many-CPU boxes, admins or distros may throttle + // resources in such a way that debuginfod would mysteriously fail. + // So we reduce the defaults: + + unsigned aff = 0; +#ifdef HAVE_SCHED_GETAFFINITY + { + int ret; + cpu_set_t mask; + CPU_ZERO(&mask); + ret = sched_getaffinity(0, sizeof(mask), &mask); + if (ret == 0) + aff = CPU_COUNT(&mask); + } +#endif + + unsigned fn = 0; +#ifdef HAVE_GETRLIMIT + { + struct rlimit rlim; + int rc = getrlimit(RLIMIT_NOFILE, &rlim); + if (rc == 0) + fn = max((rlim_t)1, (rlim.rlim_cur - 100) / 4); + // at least 2 fds are used by each listener thread etc. + // plus a bunch to account for shared libraries and such + } +#endif + + unsigned d = min(max(sth, 1U), + min(max(aff, 1U), + max(fn, 1U))); + return d; +} + + + int main (int argc, char *argv[]) { @@ -4207,7 +4262,7 @@ main (int argc, char *argv[]) /* If '-C' wasn't given or was given with no arg, pick a reasonable default for the number of worker threads. */ if (connection_pool == 0) - connection_pool = std::thread::hardware_concurrency() * 2 ?: 2; + connection_pool = default_concurrency(); /* Note that MHD_USE_EPOLL and MHD_USE_THREAD_PER_CONNECTION don't work together. */ |