On Tue, 2018-09-11 at 15:50 +0200, Peter Zijlstra wrote:
> On Tue, Sep 11, 2018 at 02:33:22PM +0100, Dmitry Safonov wrote:
> > > > You might want to think about ditching that ldsem thing
> > > > entirely,
> > > > and use a regular rwsem ?
> > >
> > > Yeah, but AFAICS, regular rwsem will need to
On Tue, 2018-09-11 at 15:50 +0200, Peter Zijlstra wrote:
> On Tue, Sep 11, 2018 at 02:33:22PM +0100, Dmitry Safonov wrote:
> > > > You might want to think about ditching that ldsem thing
> > > > entirely,
> > > > and use a regular rwsem ?
> > >
> > > Yeah, but AFAICS, regular rwsem will need to
On Tue, Sep 11, 2018 at 02:33:22PM +0100, Dmitry Safonov wrote:
> > > You might want to think about ditching that ldsem thing entirely,
> > > and use a regular rwsem ?
> >
> > Yeah, but AFAICS, regular rwsem will need to have a timeout then (for
> > write). So, I thought fixing this pile would be
On Tue, Sep 11, 2018 at 02:33:22PM +0100, Dmitry Safonov wrote:
> > > You might want to think about ditching that ldsem thing entirely,
> > > and use a regular rwsem ?
> >
> > Yeah, but AFAICS, regular rwsem will need to have a timeout then (for
> > write). So, I thought fixing this pile would be
On Tue, 2018-09-11 at 14:01 +0100, Dmitry Safonov wrote:
> On Tue, 2018-09-11 at 14:02 +0200, Peter Zijlstra wrote:
> > On Tue, Sep 11, 2018 at 02:48:21AM +0100, Dmitry Safonov wrote:
> > > It seems like when ldsem_down_read() fails with timeout, it
> > > misses
> > > update for sem->wait_readers.
On Tue, 2018-09-11 at 14:01 +0100, Dmitry Safonov wrote:
> On Tue, 2018-09-11 at 14:02 +0200, Peter Zijlstra wrote:
> > On Tue, Sep 11, 2018 at 02:48:21AM +0100, Dmitry Safonov wrote:
> > > It seems like when ldsem_down_read() fails with timeout, it
> > > misses
> > > update for sem->wait_readers.
On Tue, 2018-09-11 at 14:02 +0200, Peter Zijlstra wrote:
> On Tue, Sep 11, 2018 at 02:48:21AM +0100, Dmitry Safonov wrote:
> > It seems like when ldsem_down_read() fails with timeout, it misses
> > update for sem->wait_readers. By that reason, when writer finally
> > releases write end of the
On Tue, 2018-09-11 at 14:02 +0200, Peter Zijlstra wrote:
> On Tue, Sep 11, 2018 at 02:48:21AM +0100, Dmitry Safonov wrote:
> > It seems like when ldsem_down_read() fails with timeout, it misses
> > update for sem->wait_readers. By that reason, when writer finally
> > releases write end of the
On Tue, Sep 11, 2018 at 02:48:21AM +0100, Dmitry Safonov wrote:
> It seems like when ldsem_down_read() fails with timeout, it misses
> update for sem->wait_readers. By that reason, when writer finally
> releases write end of the semaphore __ldsem_wake_readers() does adjust
> sem->count with wrong
On Tue, Sep 11, 2018 at 02:48:21AM +0100, Dmitry Safonov wrote:
> It seems like when ldsem_down_read() fails with timeout, it misses
> update for sem->wait_readers. By that reason, when writer finally
> releases write end of the semaphore __ldsem_wake_readers() does adjust
> sem->count with wrong
It seems like when ldsem_down_read() fails with timeout, it misses
update for sem->wait_readers. By that reason, when writer finally
releases write end of the semaphore __ldsem_wake_readers() does adjust
sem->count with wrong value:
sem->wait_readers * (LDSEM_ACTIVE_BIAS - LDSEM_WAIT_BIAS)
I.e,
It seems like when ldsem_down_read() fails with timeout, it misses
update for sem->wait_readers. By that reason, when writer finally
releases write end of the semaphore __ldsem_wake_readers() does adjust
sem->count with wrong value:
sem->wait_readers * (LDSEM_ACTIVE_BIAS - LDSEM_WAIT_BIAS)
I.e,
12 matches
Mail list logo
