1414073 - Rename arena_bin_t fields

Status: RESOLVED FIXED

(Core :: Memory Allocator, enhancement)

Comment 1

[Mike Hommey [:glandium]]

Attachment: Bug 1414073 - Rename arena_bin_t fields.

The only remaining item is the number of runs in the bin, and it's only
used from jemalloc_stats, which is already iterating the runs in the bin
anyways, so it might as well count them while doing so.

Review commit: https://reviewboard.mozilla.org/r/195962/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/195962/

Comment 2

[Nicholas Nethercote [inactive]]

Comment on attachment 8924733 [details]
Bug 1414073 - Rename arena_bin_t fields.

https://reviewboard.mozilla.org/r/195962/#review201220

Cool. My experience with memory reporting is that maintained counters are error-prone and traversals are better.

Did you validate the new number by comparing it to the old one before you removed the old one?

Comment 3

[Mike Hommey [:glandium]]

Thank you for making me double check. Turns out I hadn't stress tested enough, and this actually breaks things, because "runs" is actually a bad field name: runs that are 100% full are not in there.

Comment 4

[Mike Hommey [:glandium]]

So let's morph this bug.

Comment 5

[Mike Hommey [:glandium]]

Comment on attachment 8924733 [details]
Bug 1414073 - Rename arena_bin_t fields.

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/195962/diff/1-2/

Comment 6

[Nicholas Nethercote [inactive]]

Comment on attachment 8924733 [details]
Bug 1414073 - Rename arena_bin_t fields.

https://reviewboard.mozilla.org/r/195962/#review201228

::: memory/build/mozjemalloc.cpp:816
(Diff revision 2)
>    // objects packed well, and it can also help reduce the number of
>    // almost-empty chunks.
> -  RedBlackTree<arena_chunk_map_t, ArenaRunTreeTrait> runs;
> +  RedBlackTree<arena_chunk_map_t, ArenaRunTreeTrait> mNonFullRuns;
>  
>    // Size of regions in a run for this bin's size class.
> -  size_t reg_size;
> +  size_t mSizeClass;

Is this name right? It doesn't match the comment.

::: memory/build/mozjemalloc.cpp:825
(Diff revision 2)
>  
>    // Total number of regions in a run for this bin's size class.
> -  uint32_t nregs;
> +  uint32_t mRunNumRegions;
>  
>    // Number of elements in a run's regs_mask for this bin's size class.
> -  uint32_t regs_mask_nelms;
> +  uint32_t mRunNumRegionsMask;

This comment needs changing?

::: memory/build/mozjemalloc.cpp:830
(Diff revision 2)
> -  uint32_t regs_mask_nelms;
> +  uint32_t mRunNumRegionsMask;
>  
>    // Offset of first region in a run for this bin's size class.
> -  uint32_t reg0_offset;
> +  uint32_t mRunFirstRegionOffset;
>  
> -  // Bin statistics.
> +  // Current number of runs in this bin.

Is that both full and non-full runs?

Comment 7

[Mike Hommey [:glandium]]

(In reply to Nicholas Nethercote [:njn] from comment #6)
> Comment on attachment 8924733 [details]
> Bug 1414073 - Rename arena_bin_t fields.
> 
> https://reviewboard.mozilla.org/r/195962/#review201228
> 
> ::: memory/build/mozjemalloc.cpp:816
> (Diff revision 2)
> >    // objects packed well, and it can also help reduce the number of
> >    // almost-empty chunks.
> > -  RedBlackTree<arena_chunk_map_t, ArenaRunTreeTrait> runs;
> > +  RedBlackTree<arena_chunk_map_t, ArenaRunTreeTrait> mNonFullRuns;
> >  
> >    // Size of regions in a run for this bin's size class.
> > -  size_t reg_size;
> > +  size_t mSizeClass;
> 
> Is this name right? It doesn't match the comment.

The comment is actually confusing. It's simply the size class. I'll change the comment.

> ::: memory/build/mozjemalloc.cpp:825
> (Diff revision 2)
> >  
> >    // Total number of regions in a run for this bin's size class.
> > -  uint32_t nregs;
> > +  uint32_t mRunNumRegions;
> >  
> >    // Number of elements in a run's regs_mask for this bin's size class.
> > -  uint32_t regs_mask_nelms;
> > +  uint32_t mRunNumRegionsMask;
> 
> This comment needs changing?

The comment is actually good. The member name, not so great. Naming is hard :(
 
> ::: memory/build/mozjemalloc.cpp:830
> (Diff revision 2)
> > -  uint32_t regs_mask_nelms;
> > +  uint32_t mRunNumRegionsMask;
> >  
> >    // Offset of first region in a run for this bin's size class.
> > -  uint32_t reg0_offset;
> > +  uint32_t mRunFirstRegionOffset;
> >  
> > -  // Bin statistics.
> > +  // Current number of runs in this bin.
> 
> Is that both full and non-full runs?

Would "Current total number of runs" make it clearer? Or should I add "full and non-full"?

Comment 8

[Mike Hommey [:glandium]]

Comment on attachment 8924733 [details]
Bug 1414073 - Rename arena_bin_t fields.

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/195962/diff/2-3/

Comment 9

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/e6d86b7284ba
Rename arena_bin_t fields. r=njn

Comment 10

[Narcis Beleuzu [:NarcisB]]

https://hg.mozilla.org/mozilla-central/rev/e6d86b7284ba