At Tue, 28 Sep 2004 18:33:57 +0300,
Ognyan Kulev wrote:
>
> Neal H. Walfield wrote:
> > This looks correct to me. Normally, I would say that this sort of
> > micro-optimization does not matter as we don't care how slow the error
> > path is, however, the other jump to allow_term_out (on the fast path)
> > also has a gratuitous unlock relock sequence:
> >
> > /* Let someone else in. */
> > _pager_release_seqno (p, seqno);
> > mutex_unlock (&p->interlock);
> >
> > if (!doread)
> > goto allow_term_out;
> >
> > So, if wold be useful to also move the if above the unlock and moved
> > the mutex_lock in allow_term_out to error_read and adjusted callers.
>
> Does this apply to goto error_read too?
No. The error_read assumes that the interlock is held and that is the
correct assumption for all of the callers (and therefore no fix up is
required).
> Actually, I haven't though that
> unlock-relock is a problem here.
An unlock followed by a relock is just gratuitous. In the fast path
we want to avoid them.
> >> err = _pager_pagemap_resize (p, offset + length);
> >> if (err)
> >>- goto release_out; /* Can't do much about the actual error. */
> >>+ {
> >>+ _pager_allow_termination (p);
> >>+ goto release_out; /* Can't do much about the actual error. */
> >>+ }
> >
> > This only solves half the problem. You also have to call
> > _pager_release_seqno as well.
>
> It's called in release_out.
You're right, sorry. (It is not called in allow_term_out which is
what I now remembering looking at.)
> > 2004-09-28 Neal H. Walfield <[EMAIL PROTECTED]>
> > Ognyan Kulev <[EMAIL PROTECTED]>
>
> I'm not sure this style is correct.
Something similar to this has been used in glibc for collaboration:
2004-01-02 Jakub Jelinek <[EMAIL PROTECTED]>
Paolo Bonzini <[EMAIL PROTECTED]>
* posix/regex_internal.h (re_const_bitset_ptr_t): New type.
...
Thanks,
Neal
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