From eecd7ddfcfcaa0f496701c76876f042f35073ce2 Mon Sep 17 00:00:00 2001 From: Tim Murray Date: Fri, 9 Nov 2018 09:10:12 -0800 Subject: [PATCH] libpsi: initial revision New library to create, register and destroy PSI monitors in a consistent way with lmkd. Test: used within lmkd Bug: 111308141 Change-Id: If243a97f178e90fe41e2de90c7b858ba82440279 Signed-off-by: Suren Baghdasaryan --- lmkd/libpsi/Android.bp | 22 ++++++++ lmkd/libpsi/OWNERS | 1 + lmkd/libpsi/include/psi/psi.h | 68 ++++++++++++++++++++++++ lmkd/libpsi/psi.c | 99 +++++++++++++++++++++++++++++++++++ 4 files changed, 190 insertions(+) create mode 100644 lmkd/libpsi/Android.bp create mode 100644 lmkd/libpsi/OWNERS create mode 100644 lmkd/libpsi/include/psi/psi.h create mode 100644 lmkd/libpsi/psi.c diff --git a/lmkd/libpsi/Android.bp b/lmkd/libpsi/Android.bp new file mode 100644 index 000000000..8a970942e --- /dev/null +++ b/lmkd/libpsi/Android.bp @@ -0,0 +1,22 @@ +cc_library_headers { + name: "libpsi_headers", + export_include_dirs: ["include"], +} + +cc_library { + name: "libpsi", + srcs: ["psi.c"], + shared_libs: [ + "liblog" + ], + header_libs: [ + "libpsi_headers", + ], + export_header_lib_headers: [ + "libpsi_headers", + ], + cflags: [ + "-Wall", + "-Werror", + ], +} diff --git a/lmkd/libpsi/OWNERS b/lmkd/libpsi/OWNERS new file mode 100644 index 000000000..b15bb4870 --- /dev/null +++ b/lmkd/libpsi/OWNERS @@ -0,0 +1 @@ +surenb@google.com diff --git a/lmkd/libpsi/include/psi/psi.h b/lmkd/libpsi/include/psi/psi.h new file mode 100644 index 000000000..cd49e8b60 --- /dev/null +++ b/lmkd/libpsi/include/psi/psi.h @@ -0,0 +1,68 @@ +/* + * Copyright (C) 2018 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#ifndef __ANDROID_PSI_H__ +#define __ANDROID_PSI_H__ + +#include +#include + +__BEGIN_DECLS + +enum psi_stall_type { + PSI_SOME, + PSI_FULL, + PSI_TYPE_COUNT +}; + +/* + * Initializes psi monitor. + * stall_type, threshold_us and window_us are monitor parameters + * When successful, the function returns file descriptor that can + * be used with poll/epoll syscalls to wait for EPOLLPRI events. + * When unsuccessful, the function returns -1 and errno is set + * appropriately. + */ +int init_psi_monitor(enum psi_stall_type stall_type, + int threshold_us, int window_us); + +/* + * Registers psi monitor file descriptor fd on the epoll instance + * referred to by the file descriptor epollfd. + * data parameter will be associated with event's epoll_data.ptr + * member. + */ +int register_psi_monitor(int epollfd, int fd, void* data); + +/* + * Unregisters psi monitor file descriptor fd from the epoll instance + * referred to by the file descriptor epollfd. + */ +int unregister_psi_monitor(int epollfd, int fd); + +/* + * Destroys psi monitor. + * fd is the file descriptor returned by psi monitor initialization + * routine. + * Note that if user process exits without calling this routine + * kernel will destroy the monitor as its lifetime is linked to + * the file descriptor. + */ +void destroy_psi_monitor(int fd); + +__END_DECLS + +#endif // __ANDROID_PSI_H__ diff --git a/lmkd/libpsi/psi.c b/lmkd/libpsi/psi.c new file mode 100644 index 000000000..f4d5d1878 --- /dev/null +++ b/lmkd/libpsi/psi.c @@ -0,0 +1,99 @@ +/* + * Copyright (C) 2018 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#define LOG_TAG "libpsi" + +#include +#include +#include + +#include +#include "psi/psi.h" + +#define PSI_MON_FILE_MEMORY "/proc/pressure/memory" + +static const char* stall_type_name[] = { + "some", + "full", +}; + +int init_psi_monitor(enum psi_stall_type stall_type, + int threshold_us, int window_us) { + int fd; + int res; + char buf[256]; + + fd = TEMP_FAILURE_RETRY(open(PSI_MON_FILE_MEMORY, O_WRONLY | O_CLOEXEC)); + if (fd < 0) { + ALOGE("No kernel psi monitor support (errno=%d)", errno); + return -1; + } + + switch (stall_type) { + case (PSI_SOME): + case (PSI_FULL): + res = snprintf(buf, sizeof(buf), "%s %d %d", + stall_type_name[stall_type], threshold_us, window_us); + break; + default: + ALOGE("Invalid psi stall type: %d", stall_type); + errno = EINVAL; + goto err; + } + + if (res >= (ssize_t)sizeof(buf)) { + ALOGE("%s line overflow for psi stall type '%s'", + PSI_MON_FILE_MEMORY, stall_type_name[stall_type]); + errno = EINVAL; + goto err; + } + + res = TEMP_FAILURE_RETRY(write(fd, buf, strlen(buf) + 1)); + if (res < 0) { + ALOGE("%s write failed for psi stall type '%s'; errno=%d", + PSI_MON_FILE_MEMORY, stall_type_name[stall_type], errno); + goto err; + } + + return fd; + +err: + close(fd); + return -1; +} + +int register_psi_monitor(int epollfd, int fd, void* data) { + int res; + struct epoll_event epev; + + epev.events = EPOLLPRI; + epev.data.ptr = data; + res = epoll_ctl(epollfd, EPOLL_CTL_ADD, fd, &epev); + if (res < 0) { + ALOGE("epoll_ctl for psi monitor failed; errno=%d", errno); + } + return res; +} + +int unregister_psi_monitor(int epollfd, int fd) { + return epoll_ctl(epollfd, EPOLL_CTL_DEL, fd, NULL); +} + +void destroy_psi_monitor(int fd) { + if (fd >= 0) { + close(fd); + } +}