diff options
| -rw-r--r-- | src/basic/util.c | 27 | ||||
| -rw-r--r-- | src/basic/util.h | 1 | ||||
| -rw-r--r-- | src/core/load-fragment.c | 2 | ||||
| -rw-r--r-- | src/login/logind-user.c | 2 | ||||
| -rw-r--r-- | src/login/logind.c | 2 | ||||
| -rw-r--r-- | src/test/test-util.c | 38 |
6 files changed, 68 insertions, 4 deletions
diff --git a/src/basic/util.c b/src/basic/util.c index 88d58cd94a..09d16697b7 100644 --- a/src/basic/util.c +++ b/src/basic/util.c @@ -805,6 +805,33 @@ uint64_t physical_memory(void) { return MIN(mem, lim); } +uint64_t physical_memory_scale(uint64_t v, uint64_t max) { + uint64_t p, m, ps, r; + + assert(max > 0); + + /* Returns the physical memory size, multiplied by v divided by max. Returns UINT64_MAX on overflow. On success + * the result is a multiple of the page size (rounds down). */ + + ps = page_size(); + assert(ps > 0); + + p = physical_memory() / ps; + assert(p > 0); + + m = p * v; + if (m / p != v) + return UINT64_MAX; + + m /= max; + + r = m * ps; + if (r / ps != m) + return UINT64_MAX; + + return r; +} + int update_reboot_parameter_and_warn(const char *param) { int r; diff --git a/src/basic/util.h b/src/basic/util.h index 9e6df19ef1..db105197e8 100644 --- a/src/basic/util.h +++ b/src/basic/util.h @@ -184,6 +184,7 @@ int namespace_open(pid_t pid, int *pidns_fd, int *mntns_fd, int *netns_fd, int * int namespace_enter(int pidns_fd, int mntns_fd, int netns_fd, int userns_fd, int root_fd); uint64_t physical_memory(void); +uint64_t physical_memory_scale(uint64_t v, uint64_t max); int update_reboot_parameter_and_warn(const char *param); diff --git a/src/core/load-fragment.c b/src/core/load-fragment.c index 05852cc7e3..58d7275a96 100644 --- a/src/core/load-fragment.c +++ b/src/core/load-fragment.c @@ -2821,7 +2821,7 @@ int config_parse_memory_limit( return 0; } } else - bytes = (((physical_memory() / page_size()) * (uint64_t) r) / 100) * page_size(); + bytes = physical_memory_scale(r, 100U); if (bytes < 1) { log_syntax(unit, LOG_ERR, filename, line, 0, "Memory limit '%s' too small. Ignoring.", rvalue); diff --git a/src/login/logind-user.c b/src/login/logind-user.c index 6d0904f5ca..de44d369cf 100644 --- a/src/login/logind-user.c +++ b/src/login/logind-user.c @@ -853,7 +853,7 @@ int config_parse_tmpfs_size( /* First, try to parse as percentage */ r = parse_percent(rvalue); if (r > 0 && r < 100) - *sz = PAGE_ALIGN((size_t) ((physical_memory() * (uint64_t) r) / 100U)); + *sz = physical_memory_scale(r, 100U); else { uint64_t k; diff --git a/src/login/logind.c b/src/login/logind.c index caf149cfb7..d01dd110ea 100644 --- a/src/login/logind.c +++ b/src/login/logind.c @@ -61,7 +61,7 @@ static void manager_reset_config(Manager *m) { m->idle_action_usec = 30 * USEC_PER_MINUTE; m->idle_action = HANDLE_IGNORE; - m->runtime_dir_size = PAGE_ALIGN((size_t) (physical_memory() / 10)); /* 10% */ + m->runtime_dir_size = physical_memory_scale(10U, 100U); /* 10% */ m->user_tasks_max = 12288; m->sessions_max = 8192; m->inhibitors_max = 8192; diff --git a/src/test/test-util.c b/src/test/test-util.c index 5b3fbcff53..e177612a9f 100644 --- a/src/test/test-util.c +++ b/src/test/test-util.c @@ -273,7 +273,42 @@ static void test_physical_memory(void) { assert_se(p < UINT64_MAX); assert_se(p % page_size() == 0); - log_info("Memory: %s", format_bytes(buf, sizeof(buf), p)); + log_info("Memory: %s (%" PRIu64 ")", format_bytes(buf, sizeof(buf), p), p); +} + +static void test_physical_memory_scale(void) { + uint64_t p; + + p = physical_memory(); + + assert_se(physical_memory_scale(0, 100) == 0); + assert_se(physical_memory_scale(100, 100) == p); + + log_info("Memory original: %" PRIu64, physical_memory()); + log_info("Memory scaled by 50%%: %" PRIu64, physical_memory_scale(50, 100)); + log_info("Memory divided by 2: %" PRIu64, physical_memory() / 2); + log_info("Page size: %zu", page_size()); + + /* There might be an uneven number of pages, hence permit these calculations to be half a page off... */ + assert_se(page_size()/2 + physical_memory_scale(50, 100) - p/2 <= page_size()); + assert_se(physical_memory_scale(200, 100) == p*2); + + assert_se(physical_memory_scale(0, 1) == 0); + assert_se(physical_memory_scale(1, 1) == p); + assert_se(physical_memory_scale(2, 1) == p*2); + + assert_se(physical_memory_scale(0, 2) == 0); + + assert_se(page_size()/2 + physical_memory_scale(1, 2) - p/2 <= page_size()); + assert_se(physical_memory_scale(2, 2) == p); + assert_se(physical_memory_scale(4, 2) == p*2); + + assert_se(physical_memory_scale(0, UINT32_MAX) == 0); + assert_se(physical_memory_scale(UINT32_MAX, UINT32_MAX) == p); + + /* overflow */ + assert_se(physical_memory_scale(UINT64_MAX/4, UINT64_MAX) == UINT64_MAX); + } int main(int argc, char *argv[]) { @@ -291,6 +326,7 @@ int main(int argc, char *argv[]) { test_execute_directory(); test_raw_clone(); test_physical_memory(); + test_physical_memory_scale(); return 0; } |