1、如何在iPhone上查看
设置-通用-分析-分析数据- JetsamEvent+日志 打头的系统日志。
2、如何在Mac 上查看此类分析日志
1、手机链接MAC
2、打开iTunes,点开手机图标
3、点击同步按钮
日志会被同步到MAC中的以下目录中
/users/userName/Library/Logs/CrashReporter/MobileDevice/
3、关于日志的分析：
利用jetsamEvent 可以帮助我们查看被系统清理的APP内存占用情况。
{"bug_type":"298","timestamp":"2019-04-18 00:41:32.72 +0800","os_version":"iPhone OS 11.3.1 (15E302)","incident_id":"65385412-FCF1-4F8B-B9BA-7E3457FA2C43"}
{
"crashReporterKey" : "cb1b46c9b29603987f13d3af5624dfe0891dcd8b",
"kernel" : "Darwin Kernel Version 17.5.0: Tue Mar 13 21:32:11 PDT 2018; root:xnu-4570.52.2~8\/RELEASE_ARM64_T8010",
"product" : "iPhone9,1",
"incident" : "65385412-FCF1-4F8B-B9BA-7E3457FA2C43",
"date" : "2019-04-18 00:41:32.67 +0800",
"build" : "iPhone OS 11.3.1 (15E302)",
"timeDelta" : 5,
"memoryStatus" : {
"compressorSize" : 50024,
"compressions" : 79275112,
"decompressions" : 61573914,
"zoneMapCap" : 402653184,
"largestZone" : "APFS_4K_OBJS",
"largestZoneSize" : 13451264,
"pageSize" : 16384,
"uncompressed" : 120159,
"zoneMapSize" : 113508352,
"memoryPages" : {
"active" : 29786,
"throttled" : 0,
"fileBacked" : 15361,
"wired" : 26461,
"anonymous" : 29604,
"purgeable" : 33,
"inactive" : 13602,
"free" : 2391,
"speculative" : 1577
}
}
...
,
"largestProcess" : "JD4iPhone",
"genCounter" : 1,
"processes" : [
{
"uuid" : "89715e1a-af5d-3c31-920a-b842f063e8be",
"states" : [
"daemon",
"idle"
],
"lifetimeMax" : 235,
"age" : 1270330434891,
"purgeable" : 0,
"fds" : 50,
"coalition" : 366,
"rpages" : 115,
"pid" : 19692,
"idleDelta" : 3632517,
"name" : "revisiond",
"cpuTime" : 2.8573390000000001
},
...
{
"uuid" : "616cc66b-7c0b-3bd5-89ff-af63bd94dbb7",
"states" : [
"suspended"
],
"lifetimeMax" : 14774,
"age" : 82573963110,
"purgeable" : 0,
"fds" : 100,
"coalition" : 4389,
"rpages" : 10898,
"pid" : 20571,
"idleDelta" : 14614331251,
"name" : "JD4iPhone",
"cpuTime" : 268.98448000000002
},
这是一部iPhone7 产生的jetsamEvent日志的部分内容
可以基本猜测以下日志的含义：
"largestProcess" : "JD4iPhone",表示 这个叫JD4iPhone 暂用的内存最多，没猜错的话应该是京东的app。
它占用了内存页为 "rpages" : 10898,
"pageSize" : 16384, 为每页的大小 16384/1024 = 16K
那么这个应用暂用的内存就是 10898*16K = 170M
"states" : [
"suspended"
],
它的状态是挂起的。
而 "uuid" : "89715e1a-af5d-3c31-920a-b842f063e8be",的进程
它的状态是闲置，且是一个守护线程，此类线程一般是系统维护。
虽然它只占用了 "rpages" : 115, 115 个内存页。