Re: [Xen-devel] [PATCH] xen/arm: p2m: Prevent deadlock when using memaccess

2018-03-06 Thread Sergej Proskurin
Hi Julien, On 03/06/2018 12:37 PM, Julien Grall wrote: > On 06/03/18 11:06, Sergej Proskurin wrote: >> Hi Julien, > > Hi Sergej, > >> >> On 02/28/2018 04:25 PM, Julien Grall wrote: >>> Commit 7d623b358a4 "arm/mem_access: Add long-descriptor based gpt" >>> assumed the read-write lock can be taken

Re: [Xen-devel] [PATCH] xen/arm: p2m: Prevent deadlock when using memaccess

2018-03-06 Thread Julien Grall
On 06/03/18 11:06, Sergej Proskurin wrote: Hi Julien, Hi Sergej, On 02/28/2018 04:25 PM, Julien Grall wrote: Commit 7d623b358a4 "arm/mem_access: Add long-descriptor based gpt" assumed the read-write lock can be taken recursively. However, this assumption is wrong and will lead to deadlock w

Re: [Xen-devel] [PATCH] xen/arm: p2m: Prevent deadlock when using memaccess

2018-03-06 Thread Julien Grall
Hi Stefano, On 02/03/18 23:42, Stefano Stabellini wrote: On Wed, 28 Feb 2018, Julien Grall wrote: Commit 7d623b358a4 "arm/mem_access: Add long-descriptor based gpt" assumed the read-write lock can be taken recursively. However, this assumption is wrong and will lead to deadlock when the lock is

Re: [Xen-devel] [PATCH] xen/arm: p2m: Prevent deadlock when using memaccess

2018-03-06 Thread Sergej Proskurin
Hi Julien, On 02/28/2018 04:25 PM, Julien Grall wrote: > Commit 7d623b358a4 "arm/mem_access: Add long-descriptor based gpt" > assumed the read-write lock can be taken recursively. However, this > assumption is wrong and will lead to deadlock when the lock is > contended. > > To avoid the nested l

Re: [Xen-devel] [PATCH] xen/arm: p2m: Prevent deadlock when using memaccess

2018-03-02 Thread Stefano Stabellini
On Wed, 28 Feb 2018, Julien Grall wrote: > Commit 7d623b358a4 "arm/mem_access: Add long-descriptor based gpt" > assumed the read-write lock can be taken recursively. However, this > assumption is wrong and will lead to deadlock when the lock is > contended. > > To avoid the nested lock, rework the