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authorMark Salyzyn2016-09-22 11:56:51 -0500
committerMark Salyzyn2016-10-03 13:08:34 -0500
commit807e40ecc9786755e2f74a7a6a9b20c812588119 (patch)
treefecfeb7ccd2f8cb3bd5afdfd4a902f17345b0d6f /liblog/fake_log_device.c
parent57513bd5a359f735894b39f386e235cce9524a9b (diff)
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liblog: logd: Add android_lookupEventTag_len()
Allows us to mitigate the impact of MAP_PRIVATE and copy on write by calling android_lookupEventTag_len instead of android_lookupEventTag, and delaying the copy on write impact to the later. We return a string length in a supplied location along with the string pointer with android_lookupEventTag_len(const EventTagMap* map, size_t* len, int tag). The string is not guaranteed to be nul terminated. Since android_lookupEventTag() called even once can cause the memory impact, we will mark it as deprecated, but we currently have no timeframe for removal since this is a very old interface. Add an API for __android_log_is_loggable_len() that accepts the non null terminated content and fixup callers that would gain because the length is known prior to the call either in the compiler or at runtime. Tackle transition to android_lookupEventTag_len() and fixup callers. On any application that performs logging (eg: com.android.phone) /proc/<pid>/smaps before: xxxxxxxxxx-xxxxxxxxxx rw-p 00000000 fd:00 463 /system/etc/event-log-tags Size: 20 kB Rss: 20 kB Pss: 1 kB Shared_Clean: 0 kB Shared_Dirty: 20 kB Private_Clean: 0 kB Private_Dirty: 0 kB Referenced: 0 kB Anonymous: 20 kB AnonHugePages: 0 kB Swap: 0 kB SwapPss: 0 kB KernelPageSize: 4 kB MMUPageSize: 4 kB Locked: 0 kB VmFlags: rd wr mr mw me ac /proc/<pid>/smaps after: xxxxxxxxxx-xxxxxxxxxx rw-p 00000000 fd:00 1773 /system/etc/event-log-tags Size: 20 kB Rss: 20 kB Pss: 1 kB Shared_Clean: 20 kB (was 0kB) Shared_Dirty: 0 kB (was 20kB) Private_Clean: 0 kB Private_Dirty: 0 kB Referenced: 20 kB (was 0kB) Anonymous: 0 kB (was 20kB) AnonHugePages: 0 kB Swap: 0 kB SwapPss: 0 kB KernelPageSize: 4 kB MMUPageSize: 4 kB Locked: 0 kB VmFlags: rd wr mr mw me ac Added liblog-unit-tests --gtest_filter=liblog.event_log_tags to check for Shared_Clean: to not be 0 and Anonymous: to be 0 for all processes referencing event-log-tags. Which can include multiple references to /system/etc/event-log-tags and future possible refs to /data/misc/logd/event-log-tags and /dev/event-log-tags. We want failure messages to help point to errant code using the deprecated interface. This change saves 1/4MB of memory or more on a typical system. Test: gTest liblog-unit-tests Bug: 31456426 Change-Id: I9e08e44d9092bd96fe704b5709242e7195281d33
Diffstat (limited to 'liblog/fake_log_device.c')
-rw-r--r--liblog/fake_log_device.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/liblog/fake_log_device.c b/liblog/fake_log_device.c
index 1b57e7550..7bd1f83d4 100644
--- a/liblog/fake_log_device.c
+++ b/liblog/fake_log_device.c
@@ -718,3 +718,12 @@ LIBLOG_ABI_PUBLIC int __android_log_is_loggable(int prio,
718 int logLevel = def; 718 int logLevel = def;
719 return logLevel >= 0 && prio >= logLevel; 719 return logLevel >= 0 && prio >= logLevel;
720} 720}
721
722LIBLOG_ABI_PUBLIC int __android_log_is_loggable_len(int prio,
723 const char *tag __unused,
724 size_t len __unused,
725 int def)
726{
727 int logLevel = def;
728 return logLevel >= 0 && prio >= logLevel;
729}