Messages in this thread | | | Date | Tue, 23 Oct 2012 23:47:33 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: [PATCH v5] posix timers: allocate timer id per process |
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On Tue, 23 Oct 2012, Eric Dumazet wrote:
> On Tue, 2012-10-23 at 11:40 +0400, Stanislav Kinsbursky wrote: > > This patch is required CRIU project (www.criu.org). > > To migrate processes with posix timers we have to make sure, that we can > > restore posix timer with proper id. > > Currently, this is not true, because timer ids are allocated globally. > > So, this is precursor patch and it's purpose is make posix timer id to be > > allocated per process. > > > > Patch replaces global idr with global hash table for posix timers and > > makes timer ids unique not globally, but per process. Next free timer id is > > type of integer and stored on signal struct (posix_timer_id). If free timer id > > reaches negative value on timer creation, it will be dropped to zero and > > -EAGAIN will be returned to user. > > > > Hash table has 512 slots. > > Key is constructed as follows: > > key = hash_32(hash_32(current->signal) ^ posix_timer_id)); > > > > Note: with this patch, id, returned to user, is not the minimal free > > amymore. It means, that id, returned to user space in loop, listed below, will > > be increasing on each iteration till INT_MAX and then dropped to zero: > > > > while(1) { > > id = timer_create(...); > > timer_delete(id); > > } > > > > Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com> > > > > --- > > SGTM
Not so good to me.
> Signed-off-by: Eric Dumazet <edumazet@google.com>
And that should be either an Acked-by or a Reviewed-by. You can't sign off on patches which have not been submitted or transported by you.
Thanks,
tglx
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