Re: [Xen-devel] [PATCH 2/2] gnttab: improve GNTTABOP_cache_flush locking

2017-12-04 Thread Jan Beulich
>>> On 04.12.17 at 12:31, wrote: > On 12/04/2017 09:02 AM, Jan Beulich wrote: > On 01.12.17 at 16:31, wrote: >>> On 30/11/17 14:32, Jan Beulich wrote: Dropping the lock before returning from grant_map_exists() means handing possibly stale information back to the caller. Return back

Re: [Xen-devel] [PATCH 2/2] gnttab: improve GNTTABOP_cache_flush locking

2017-12-04 Thread George Dunlap
On 12/04/2017 09:02 AM, Jan Beulich wrote: On 01.12.17 at 16:31, wrote: >> On 30/11/17 14:32, Jan Beulich wrote: >>> Dropping the lock before returning from grant_map_exists() means handing >>> possibly stale information back to the caller. Return back the pointer >>> to the active entry inst

Re: [Xen-devel] [PATCH 2/2] gnttab: improve GNTTABOP_cache_flush locking

2017-12-04 Thread Jan Beulich
>>> On 01.12.17 at 16:31, wrote: > On 30/11/17 14:32, Jan Beulich wrote: >> Dropping the lock before returning from grant_map_exists() means handing >> possibly stale information back to the caller. Return back the pointer >> to the active entry instead, for the caller to release the lock once >>

Re: [Xen-devel] [PATCH 2/2] gnttab: improve GNTTABOP_cache_flush locking

2017-12-01 Thread Stefano Stabellini
On Thu, 30 Nov 2017, Jan Beulich wrote: > Dropping the lock before returning from grant_map_exists() means handing > possibly stale information back to the caller. Return back the pointer > to the active entry instead, for the caller to release the lock once > done. > > Signed-off-by: Jan Beulich

Re: [Xen-devel] [PATCH 2/2] gnttab: improve GNTTABOP_cache_flush locking

2017-12-01 Thread Andre Przywara
Hi, On 30/11/17 14:32, Jan Beulich wrote: > Dropping the lock before returning from grant_map_exists() means handing > possibly stale information back to the caller. Return back the pointer > to the active entry instead, for the caller to release the lock once > done. I don't know enough about gr

[Xen-devel] [PATCH 2/2] gnttab: improve GNTTABOP_cache_flush locking

2017-11-30 Thread Jan Beulich
Dropping the lock before returning from grant_map_exists() means handing possibly stale information back to the caller. Return back the pointer to the active entry instead, for the caller to release the lock once done. Signed-off-by: Jan Beulich --- a/xen/common/grant_table.c +++ b/xen/common/gr