[PATCH] elf: Use new dependency sorting algorithm by default

[Adhemerval Zanella]

On 14/12/2021 08:53, Florian Weimer wrote:
> The default has to change eventually, and there are no known failures
> that require a delay.
> 
> Tested on i686-linux-gnu and x86_64-linux-gnu.
> 

LGTM, thanks.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

> ---
>  NEWS                           | 7 ++++---
>  elf/dl-tunables.list           | 2 +-
>  elf/tst-rtld-list-tunables.exp | 2 +-
>  manual/tunables.texi           | 2 +-
>  4 files changed, 7 insertions(+), 6 deletions(-)
> 
> diff --git a/NEWS b/NEWS
> index b53f230cca..2aaece42f5 100644
> --- a/NEWS
> +++ b/NEWS
> @@ -60,9 +60,10 @@ Major new features:
>    of the existing sorting algorithm when encountering particular circular
>    object dependency cases.
>  
> -* A new tunable, glibc.rtld.dynamic_sort, can be used to select between the two
> -  DSO sorting algorithms.  The default setting of '1' uses the current existing
> -  algorithm, while a value of '2' selects the new DFS-based algorithm.
> +* A new tunable, glibc.rtld.dynamic_sort, can be used to select between
> +  the two DSO sorting algorithms.  The default setting of '2' uses the
> +  new DFS-based algorithm.  The setting '1' switches to the old
> +  algorithm used in glibc 2.33 and earlier.
>  
>  * ABI support for a new function '__memcmpeq'. '__memcmpeq' is meant
>    to be used by compilers for optimizing usage of 'memcmp' when its
> diff --git a/elf/dl-tunables.list b/elf/dl-tunables.list
> index 46ffb23784..ffcd7f18d4 100644
> --- a/elf/dl-tunables.list
> +++ b/elf/dl-tunables.list
> @@ -162,7 +162,7 @@ glibc {
>        type: INT_32
>        minval: 1
>        maxval: 2
> -      default: 1
> +      default: 2
>      }
>    }
>  }
> diff --git a/elf/tst-rtld-list-tunables.exp b/elf/tst-rtld-list-tunables.exp
> index 9bf572715f..44e4834cfb 100644
> --- a/elf/tst-rtld-list-tunables.exp
> +++ b/elf/tst-rtld-list-tunables.exp
> @@ -10,6 +10,6 @@ glibc.malloc.tcache_max: 0x0 (min: 0x0, max: 0x[f]+)
>  glibc.malloc.tcache_unsorted_limit: 0x0 (min: 0x0, max: 0x[f]+)
>  glibc.malloc.top_pad: 0x0 (min: 0x0, max: 0x[f]+)
>  glibc.malloc.trim_threshold: 0x0 (min: 0x0, max: 0x[f]+)
> -glibc.rtld.dynamic_sort: 1 (min: 1, max: 2)
> +glibc.rtld.dynamic_sort: 2 (min: 1, max: 2)
>  glibc.rtld.nns: 0x4 (min: 0x1, max: 0x10)
>  glibc.rtld.optional_static_tls: 0x200 (min: 0x0, max: 0x[f]+)
> diff --git a/manual/tunables.texi b/manual/tunables.texi
> index 5d50b90f64..28ff502990 100644
> --- a/manual/tunables.texi
> +++ b/manual/tunables.texi
> @@ -318,7 +318,7 @@ value of @samp{2}, a different algorithm is used, which implements a
>  topological sort through depth-first search, and does not exhibit the
>  performance issues of @samp{1}.
>  
> -The default value of this tunable is @samp{1}.
> +The default value of this tunable is @samp{2}.
>  @end deftp
>  
>  @node Elision Tunables
>