From 5327d931acc20ce524e57cb5412ebf2c8b15b34d Mon Sep 17 00:00:00 2001
From: Jaegeuk Kim <jaegeuk@google.com>
Date: Thu, 4 Jul 2019 18:09:38 -0700
Subject: [PATCH] logcatd: fallocate and fadvise to logcat files

1. Pinning and fallocating blocks can avoid filesystem fragmentation.
2. Dropping caches can avoid memory pressure.
3. Use 2MB files

Bug: 136483670
Bug: 137180754
Change-Id: I0827bd903a677cbcbf3688983e847301cd541cdd
Signed-off-by: Jaegeuk Kim <jaegeuk@google.com>
---
 logcat/logcat.cpp | 24 ++++++++++++++++++++----
 logcat/logcatd.rc |  2 +-
 2 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/logcat/logcat.cpp b/logcat/logcat.cpp
index e2711af94..4dcb3383e 100644
--- a/logcat/logcat.cpp
+++ b/logcat/logcat.cpp
@@ -32,6 +32,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <sys/cdefs.h>
+#include <sys/ioctl.h>
 #include <sys/resource.h>
 #include <sys/socket.h>
 #include <sys/stat.h>
@@ -158,8 +159,22 @@ static void logcat_panic(android_logcat_context_internal* context,
                          enum helpType showHelp, const char* fmt, ...)
     __printflike(3, 4);
 
-static int openLogFile(const char* pathname) {
-    return open(pathname, O_WRONLY | O_APPEND | O_CREAT, S_IRUSR | S_IWUSR);
+#ifndef F2FS_IOC_SET_PIN_FILE
+#define F2FS_IOCTL_MAGIC       0xf5
+#define F2FS_IOC_SET_PIN_FILE _IOW(F2FS_IOCTL_MAGIC, 13, __u32)
+#endif
+
+static int openLogFile(const char* pathname, size_t sizeKB) {
+    int fd = open(pathname, O_WRONLY | O_APPEND | O_CREAT, S_IRUSR | S_IWUSR);
+    if (fd < 0) {
+        return fd;
+    }
+
+    // no need to check errors
+    __u32 set = 1;
+    ioctl(fd, F2FS_IOC_SET_PIN_FILE, &set);
+    fallocate(fd, FALLOC_FL_KEEP_SIZE, 0, (sizeKB << 10));
+    return fd;
 }
 
 static void close_output(android_logcat_context_internal* context) {
@@ -192,6 +207,7 @@ static void close_output(android_logcat_context_internal* context) {
             if (context->fds[1] == context->output_fd) {
                 context->fds[1] = -1;
             }
+            posix_fadvise(context->output_fd, 0, 0, POSIX_FADV_DONTNEED);
             close(context->output_fd);
         }
         context->output_fd = -1;
@@ -276,7 +292,7 @@ static void rotateLogs(android_logcat_context_internal* context) {
         }
     }
 
-    context->output_fd = openLogFile(context->outputFileName);
+    context->output_fd = openLogFile(context->outputFileName, context->logRotateSizeKBytes);
 
     if (context->output_fd < 0) {
         logcat_panic(context, HELP_FALSE, "couldn't open output file");
@@ -398,7 +414,7 @@ static void setupOutputAndSchedulingPolicy(
 
     close_output(context);
 
-    context->output_fd = openLogFile(context->outputFileName);
+    context->output_fd = openLogFile(context->outputFileName, context->logRotateSizeKBytes);
 
     if (context->output_fd < 0) {
         logcat_panic(context, HELP_FALSE, "couldn't open output file");
diff --git a/logcat/logcatd.rc b/logcat/logcatd.rc
index 26c9de388..e98618440 100644
--- a/logcat/logcatd.rc
+++ b/logcat/logcatd.rc
@@ -52,7 +52,7 @@ on property:logd.logpersistd.enable=false
     stop logcatd
 
 # logcatd service
-service logcatd /system/bin/logcatd -L -b ${logd.logpersistd.buffer:-all} -v threadtime -v usec -v printable -D -f /data/misc/logd/logcat -r ${logd.logpersistd.rotate_kbytes:-1024} -n ${logd.logpersistd.size:-256} --id=${ro.build.id}
+service logcatd /system/bin/logcatd -L -b ${logd.logpersistd.buffer:-all} -v threadtime -v usec -v printable -D -f /data/misc/logd/logcat -r ${logd.logpersistd.rotate_kbytes:-2048} -n ${logd.logpersistd.size:-256} --id=${ro.build.id}
     class late_start
     disabled
     # logd for write to /data/misc/logd, log group for read from log daemon