Re: Reasoning about memory ordering

2018-02-23 Thread Nikolay Borisov
On 23.02.2018 19:31, Andrea Parri wrote: > On Fri, Feb 23, 2018 at 02:30:22PM +0200, Nikolay Borisov wrote: >> Hello, >> >> I'm cc'ing a bunch of people I know are well-versed in >> the black arts of memory ordering! >> >> Currently in btrfs we have roughly the following sequence: >> >> T1:

Re: Reasoning about memory ordering

2018-02-23 Thread Andrea Parri
On Fri, Feb 23, 2018 at 02:30:22PM +0200, Nikolay Borisov wrote: > Hello, > > I'm cc'ing a bunch of people I know are well-versed in > the black arts of memory ordering! > > Currently in btrfs we have roughly the following sequence: > > T1:

Re: Reasoning about memory ordering

2018-02-23 Thread Nikolay Borisov
On 23.02.2018 17:38, Alan Cox wrote: >> Given this is the current state of the code (it's part of btrfs) I believe >> the following could/should be done: > > Is there benchmarking data to show that a custom lock is justified > (especiaally given it's going to mean btrfs and rtlinux don't play >

Re: Reasoning about memory ordering

2018-02-23 Thread Alan Cox
> Given this is the current state of the code (it's part of btrfs) I believe > the following could/should be done: Is there benchmarking data to show that a custom lock is justified (especiaally given it's going to mean btrfs and rtlinux don't play together nicely since it won't be able to see th