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Re: why does rwlock prefer readers by default?
- From: OndÅej BÃlka <neleai at seznam dot cz>
- To: Torvald Riegel <triegel at redhat dot com>
- Cc: GLIBC Devel <libc-alpha at sourceware dot org>
- Date: Sat, 10 May 2014 19:04:43 +0200
- Subject: Re: why does rwlock prefer readers by default?
- Authentication-results: sourceware.org; auth=none
- References: <1399458831 dot 32485 dot 12625 dot camel at triegel dot csb>
On Wed, May 07, 2014 at 12:33:51PM +0200, Torvald Riegel wrote:
> POSIX makes it an implementation-defined choice whether readers or
> writers are preferred. Our current implementation's default is that
> readers are to be preferred. I couldn't find the rationale for this;
> does anybody know what it was?
>
> Otherwise, if this was an arbitrary choice, what do you all think the
> default should be? Can we change it? Should we change it to preferring
> writers?
I realized that for this discussion we should sort issues with assembly
rwlock implementations first. If we decide that some behaviour is
preffered we should keep it consistent on all architectures or it will
remain undefined for crossplatform programs.
It need either maintainers review and modify rwlock code or remove
assembly implementation. As I doubt that now assembly helps I would
check architectures if that is case before doing change.