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Re: [PATCH] Add PTHREAD_MUTEX_NORMAL_INT
- From: Andi Kleen <ak at linux dot jf dot intel dot com>
- To: Rich Felker <dalias at aerifal dot cx>
- Cc: Andi Kleen <andi at firstfloor dot org>, "Carlos O'Donell" <carlos at redhat dot com>, Andi Kleen <ak at linux dot jf dot intel dot com>, libc-alpha at sourceware dot org
- Date: Tue, 25 Jun 2013 13:40:13 -0700
- Subject: Re: [PATCH] Add PTHREAD_MUTEX_NORMAL_INT
- References: <1372105055-31254-1-git-send-email-andi at firstfloor dot org> <51C8AB50 dot 80108 at redhat dot com> <20130624203147 dot GO5643 at tassilo dot jf dot intel dot com> <51C8B797 dot 7080503 at redhat dot com> <20130624232607 dot GT6123 at two dot firstfloor dot org> <51C9B7D0 dot 5000207 at redhat dot com> <20130625170656 dot GB6123 at two dot firstfloor dot org> <20130625173203 dot GL29800 at brightrain dot aerifal dot cx>
> > commit 61dd6208fb1e59a423b6dfa712a3c896c34b2590
> > Author: Siddhesh Poyarekar <siddhesh@redhat.com>
> > Date: Sat Jun 15 12:24:15 2013 +0530
> >
> > New API to set default thread attributes
> >
> > Why are any additions I make suddenly such a big problem?
>
> A new API is very different from a new ABI version of an existing API.
The patches to implement the new version of gettype / the new NORMAL
is already separate. Also if it's really a problem we can drop it
and just do what the original patches did.
The other patches don't add any new versions, just two new bits
to two existing APIs (enable/disable elision for mutexes and
rwlocks respectively)
Also all of these patches have been already reviewed by multiple
people, including Carlos.
> Also, the tuning per-lock is not nearly as impactful as adding mutex
> type constants or changing the meaning of existing ones in subtle
> ways. Adding these new tuning functions will not affect any
> application that does not use them, i.e. any current application and
> any conforming POSIX application. On the other hand, changing NORMAL
> will affect many applications.
FWIW i spent quite some time on debian codesearch and koders.com
and I determined that NORMAL or pthread_mutexattr_settype(DEFAULT)
is not widely used at all. That was the only reason I agreed to
disable elision for NORMAL and plain settype() on old binaries.
-Andi