Changed CompressedPtr to 32 bits in size and reduced the max slab index value to 15 bits #87

guptask · 2022-06-23T07:51:11Z

This change is

It's implementation is mostly based on PosixShmSegment. Also, extend ShmManager and ShmSegmentOpts to support this new segment type.

After introducing file segment type, nameToKey_ does not provide enough information to recover/remove segments on restart. This commit fixes that by replacing nameToKey_ with nameToOpts_. Previously, the Key from nameToKey_ map was only used in a single DCHECK().

* New class MemoryTierCacheConfig allows to configure a memory tier. Setting tier size and location of a file for file-backed memory are supported in this initial implementation; * New member, vector of memory tiers, is added to class CacheAllocatorConfig. * New test suite, chelib/allocator/tests/MemoryTiersTest.cpp, demonstrates the usage of and tests extended config API.

to allow using new configureMemoryTiers() API with legacy behavior. Move validation code for memory tiers to validate() method and convert ratios to sizes lazily (on get)..

It wrongly assumed that the only possible segment type is PosixSysV segment.

… handling when NVM cache state is not enabled

Now it's size is 8 bytes intead of 4. Original CompressedPtr stored only some offset with a memory Allocator. For multi-tier implementation, this is not enough. We must also store tierId and when uncompressing, select a proper allocator. An alternative could be to just resign from CompressedPtr but they are leveraged to allow the cache to be mapped to different addresses on shared memory. Changing CompressedPtr impacted CacheItem size - it increased from 32 to 44 bytes.

Without this fix removeCb called even in case when Item is moved between tiers.

It fails because CentOS is EOL. We might want to consider using CentOS Streams but for now, just remove it. Right now, we rely on build-cachelib-centos workflow anyway.

Disabled test suite allocator-test-AllocatorTypeTest to skip sporadically failing tests.

…m#43) Compensation results in ratios being different than originially specified.

igchor · 2022-08-18T11:18:11Z

@guptask please resolve conflicts

igchor

Reviewable status: 0 of 11 files reviewed, 4 unresolved discussions (waiting on @guptask)

cachelib/allocator/memory/CompressedPtr.h line 40 at r4 (raw file):

// specialize a type for all of the STL containers.
namespace IsContainerImpl {

Why do you add all those traits and so many new includes? I don;t think listing all possible containers is a good idea... What if some new ones are added in the future?

You can just set isContainer based on whether allocators_ has compress/uncompress methods taking a compressed ptr or not: https://stackoverflow.com/questions/87372/check-if-a-class-has-a-member-function-of-a-given-signature

Or even simpler, you can probably just make a partial specialization for AllocatorT == CacheAllocator<..> and for the generic case, treat AllocatorT as a container.

instead of always inserting to topmost tier

Part 2. ---------------------------- This patch introduces tryEvictToNextMemoryTier (the actual data movement), multi-tier stats and some additional multi-tier tests. Additional features: - Add option to insert items to first free tier (pmem#87)

igchor and others added 30 commits February 10, 2022 14:55

Run centos and debian workflows on push and PR

36eae66

Introduce FileShmSegment for file-backed shared memory

790c09f

It's implementation is mostly based on PosixShmSegment. Also, extend ShmManager and ShmSegmentOpts to support this new segment type.

Adjust and enable tests for ShmFileSegment

aed38aa

Integrate Memory Tier config API with CacheAllocator.

3186b94

Add MemoryTierCacheConfig::fromShm()

38515ac

to allow using new configureMemoryTiers() API with legacy behavior. Move validation code for memory tiers to validate() method and convert ratios to sizes lazily (on get)..

Fix test_shm_manager.cpp test

48b68a3

It wrongly assumed that the only possible segment type is PosixSysV segment.

Run tests on CI

6fe4971

Run long tests (navy/bench) every day on CI

dff2296

Moved common segment code for posix and file shm segments into ShmCommon

3af7643

Enabled memory tier config API for cachebench.

c93b440

Enabled shared memory tier in cachebench.

ab752e8

Converted nvmCacheState_ to std::optional to simplify NVM cache state…

2cacc99

… handling when NVM cache state is not enabled

Run CI on prebuild docker image

9ace595

Run only centos build on CI

9812286

Initial multi-tier support implementation

e111395

Implemented async Item movement between tiers

9ae9b2e

Adding example for multitiered cache

3b68053

Enable workarounds in tests

bef878e

Add basic multi-tier test

0e8af04

Set correct size for each memory tier

4477fec

Extend cachbench with value validation

53ca174

Aadding new configs to hit_ratio/graph_cache_leader_fobj

8b83aab

Move validateValue call to make sure it is measured by latency tracker

7b36c51

Fix eviction flow and removeCb calls

d817018

Without this fix removeCb called even in case when Item is moved between tiers.

Remove failing build-cachelib workflow (pmem#42)

385128d

It fails because CentOS is EOL. We might want to consider using CentOS Streams but for now, just remove it. Right now, we rely on build-cachelib-centos workflow anyway.

Disabled test suite allocator-test-AllocatorTypeTest (pmem#41)

d13568e

Disabled test suite allocator-test-AllocatorTypeTest to skip sporadically failing tests.

Do not compensate for rounding error when calculating tier sizes (pme…

02a3bfb

…m#43) Compensation results in ratios being different than originially specified.

guptask force-pushed the compressed_ptr_size_reduction branch 2 times, most recently from 9492096 to 0c3df03 Compare August 2, 2022 09:50

guptask marked this pull request as ready for review August 2, 2022 09:52

guptask force-pushed the compressed_ptr_size_reduction branch 4 times, most recently from 4936efd to a875c4b Compare August 3, 2022 07:23

guptask changed the title ~~Changed CompressedPtr to 32 bits in size and reduced the max slab index value to 15 bits~~ [Upstream] Changed CompressedPtr to 32 bits in size and reduced the max slab index value to 15 bits Aug 3, 2022

guptask changed the title ~~[Upstream] Changed CompressedPtr to 32 bits in size and reduced the max slab index value to 15 bits~~ Changed CompressedPtr to 32 bits in size and reduced the max slab index value to 15 bits Aug 3, 2022

guptask force-pushed the compressed_ptr_size_reduction branch 7 times, most recently from c8421a3 to df1a2a9 Compare August 18, 2022 00:20

changed compressed ptr to 32 bits and slab indx size to 15 bits

6fb2e74

guptask force-pushed the compressed_ptr_size_reduction branch from df1a2a9 to 6fb2e74 Compare August 18, 2022 02:10

igchor requested changes Aug 18, 2022

View reviewed changes

vinser52 force-pushed the develop branch from 11fadaa to 6122ab9 Compare September 13, 2022 10:57

guptask closed this Dec 16, 2022

byrnedj pushed a commit to byrnedj/CacheLib that referenced this pull request Jun 15, 2023

Add option to insert items to first free tier (pmem#87)

946b95b

instead of always inserting to topmost tier

byrnedj pushed a commit to byrnedj/CacheLib that referenced this pull request Jul 24, 2023

Add option to insert items to first free tier (pmem#87)

5632d18

instead of always inserting to topmost tier

byrnedj pushed a commit to byrnedj/CacheLib that referenced this pull request Mar 12, 2024

Add option to insert items to first free tier (pmem#87)

7422f02

instead of always inserting to topmost tier

byrnedj pushed a commit to byrnedj/CacheLib that referenced this pull request May 8, 2024

Add option to insert items to first free tier (pmem#87)

6449d6c

instead of always inserting to topmost tier

byrnedj pushed a commit to byrnedj/CacheLib that referenced this pull request May 20, 2024

Add option to insert items to first free tier (pmem#87)

7d06531

instead of always inserting to topmost tier

byrnedj pushed a commit to byrnedj/CacheLib that referenced this pull request Jun 25, 2024

Add option to insert items to first free tier (pmem#87)

30b330f

instead of always inserting to topmost tier

byrnedj pushed a commit to byrnedj/CacheLib that referenced this pull request Jun 27, 2024

Add option to insert items to first free tier (pmem#87)

9ec649d

instead of always inserting to topmost tier

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Changed CompressedPtr to 32 bits in size and reduced the max slab index value to 15 bits #87

Changed CompressedPtr to 32 bits in size and reduced the max slab index value to 15 bits #87

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guptask commented Jun 23, 2022 •

edited by igchor

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igchor commented Aug 18, 2022

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Changed CompressedPtr to 32 bits in size and reduced the max slab index value to 15 bits #87

Changed CompressedPtr to 32 bits in size and reduced the max slab index value to 15 bits #87

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guptask commented Jun 23, 2022 •

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