Managed runtime cache analysis

Patent metadata

Field	Value
Publication number	US-9734204-B2
Application number	US-201414567156-A
Country	US
Kind code	B2
Filing date	Dec 11, 2014
Priority date	Dec 11, 2014
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

Analyzing a managed runtime cache is provided. A heap associated with a managed runtime environment, where the heap includes an N-generation cache or a plurality of objects associated with a program operating within a managed runtime environment is identified. A snapshot of the heap is produced, wherein the snapshot identifies a memory location for each object of the plurality of objects at which the object is stored. A generation of each of the plurality of objects based, at least in part, on the memory location of the object is determined. One or more suggestions based, at least in part, on the memory location of the plurality of objects is provided.

First claim

What is claimed is:

1. A computer program product (CPP) for use with a managed runtime cache, the CPP comprising:
a storage device; and
computer code stored in the storage device, with the computer code including machine readable instructions and data for causing a computer to perform operations including at least the following:
during runtime of a set of application(s), performing garbage collection on the managed runtime cache under a garbage collection policy such that there is a heap of data identifying garbage under collection with the heap being logically organized into a plurality of N generations,
determining that an application state with respect to the set of applications is steady,
responsive to the determination that the application state is steady, generating a first snapshot of the heap,
locating a cache container object corresponding to the managed runtime cache in the heap,
for each given object of a plurality of objects in the managed runtime cache:
finding the given object in the heap,
determining a generation value of the given object based on memory segments,
mapping an address of the given object to the memory segments used in the determination of the generation value, and
recording the generation value of the given object, and

for each given generation of the plurality of N generations of the heap, calculating a proportion of cached objects having a generation value equal to the given generation; and
determining that the proportion of cached objects in a base generation is above a predetermined threshold; and
determining that a cache implementation algorithm is functioning with substandard efficiency based, at least in part, on the determination that the proportion of cached objects in a base generation is above the predetermined threshold.

2. The CPP of claim 1 wherein the computer code further includes machine readable instructions and data for causing the processor(s) set to perform operation:
responsive to the determination that the cache implementation algorithm is functioning with substandard efficiency, increasing the size of the cache.

3. The CPP of claim 1 wherein the computer code further includes machine readable instructions and data for causing the processor(s) set to perform operation:
responsive to the determination that the cache implementation algorithm is functioning with substandard efficiency, decreasing the size of cache.

4. A computer system for use with a managed runtime cache, the computer system comprising:
a processor(s) set;
a storage device structured and connected to store code in a manner so that the code can be executed by the processor(s) set; and
computer code stored in the storage device, with the computer code including machine readable instructions and data for causing the processor(s) set to perform operations including at least the following:
during runtime of a set of application(s), performing garbage collection on the managed runtime cache under a garbage collection policy such that there is a heap of data identifying garbage under collection with the heap being logically organized into a plurality of N generations,
determining that an application state with respect to the set of applications is steady,
responsive to the determination that the application state is steady, generating a first snapshot of the heap,
locating a cache container object corresponding to the managed runtime cache in the heap,
for each given object of a plurality of objects in the managed runtime cache:
finding the given object in the heap,
determining a generation value of the given object based on memory segments,
mapping an address of the given object to the memory segments used in the determination of the generation value, and
recording the generation value of the given object, and

for each given generation of the plurality of N generations of the heap, calculating a proportion of cached objects having a generation value equal to the given generation; and
determining that the proportion of cached objects in a base generation is above a predetermined threshold; and
determining that a cache implementation algorithm is functioning with substandard efficiency based, at least in part, on the determination that the proportion of cached objects in a base generation is above the predetermined threshold.

5. The computer system of claim 4 wherein the computer code further includes machine readable instructions and data for causing the processor(s) set to perform operation:
responsive to the determination that the cache implementation algorithm is functioning with substandard efficiency, increasing the size of the cache.

6. The computer system of claim 4 wherein the computer code further includes machine readable instructions and data for causing the processor(s) set to perform operation:
responsive to the determination that the cache implementation algorithm is functioning with substandard efficiency, decreasing the size of cache.

7. A computer program product (CPP) for use with a managed runtime cache, the CPP comprising:
a storage device; and
computer code stored in the storage device, with the computer code including machine readable instructions and data for causing a computer to perform operations including at least the following:
during runtime of a set of application(s), performing garbage collection on the managed runtime cache under a garbage collection policy such that there is a heap of data identifying garbage under collection with the heap being logically organized into a plurality of N generations,
determining that an application state with respect to the set of applications is steady,
responsive to the determination that the application state is steady, generating a first snapshot of the heap,
locating a cache container object corresponding to the managed runtime cache in the heap,
for each given object of a plurality of objects in the managed runtime cache:
finding the given object in the heap,
determining a generation value of the given object based on memory segments,
mapping an address of the given object to the memory segments used in the determination of the generation value, and
recording the generation value of the given object, and

for each given generation of the plurality of N generations of the heap, calculating a proportion of cached objects having a generation value equal to the given generation; and
determining that the proportion of cached objects in a base generation is above a predetermined threshold; and
determining that the performance of garbage collection is functioning with substandard efficiency based, at least in part, on the determination that the proportion of cached objects in a base generation is above the predetermined threshold.

8. The CPP of claim 7 wherein the computer code further includes machine readable instructions and data for causing the processor(s) set to perform operation:
responsive to the determination that the performance of garbage collection is functioning with substandard efficiency, changing the garbage collection policy.

Assignees

• IBM

Inventors

• Chamberlain Richard N
• Hellyer Howard J
• Peters Matthew F
• Pilkington Adam J

Classifications

• G06F11/3037 Primary

  where the computing system component is a memory, e.g. virtual memory, cache (accessing, addressing or allocating within memory systems or architectures G06F12/00; checking stores for correct operation G11C29/00) · CPC title

• G06F2212/1044

  Space efficiency improvement · CPC title

• G06F9/46

  Multiprogramming arrangements · CPC title

• G06F12/0802

  Addressing of a memory level in which the access to the desired data or data block requires associative addressing means, e.g. caches · CPC title

• G06F2212/7205

  Cleaning, compaction, garbage collection, erase control · CPC title