Re: [PATCH 0/5] Simplify /proc/$pid/maps implementation

[Vlastimil Babka]

On 2/29/20 5:59 PM, Matthew Wilcox wrote:
> From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>

Re: subject, it's not only maps, but also smaps, smaps_rollu, numa_maps

> Back in 2005, we merged a patch from Akamai that sped up /proc/$pid/maps
> by using f_version to stash the user virtual address that we'd just
> displayed.  That wasn't necessary; we can just use the private *ppos for
> the same purpose.  There have also been some other odd choices made over
> the years that use the seq_file infrastructure in some non-idiomatic ways.
> 
> Tested by using 'dd' with various different 'bs=' parameters to check that
> calling ->start, ->stop and ->next at various offsets work as expected.
> 
> Matthew Wilcox (Oracle) (5):
>   proc: Inline vma_stop into m_stop
>   proc: remove m_cache_vma
>   proc: Use ppos instead of m->version
>   seq_file: Remove m->version
>   proc: Inline m_next_vma into m_next

For all of them:

Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
Thanks!

>  fs/proc/task_mmu.c       | 95 +++++++++++++---------------------------
>  fs/seq_file.c            | 28 ------------
>  include/linux/seq_file.h |  1 -
>  3 files changed, 31 insertions(+), 93 deletions(-)
> 
> base-commit: d5226fa6dbae0569ee43ecfc08bdcd6770fc4755
>