Messages in this thread | | | From | Praveen Kannoju <> | Subject | RE: [PATCH RFC] rds: ib: Reduce the contention caused by the asynchronous workers to flush the mr pool | Date | Wed, 19 Jan 2022 13:12:29 +0000 |
| |
-----Original Message----- From: Jason Gunthorpe [mailto:jgg@ziepe.ca] Sent: 19 January 2022 06:35 PM To: Praveen Kannoju <praveen.kannoju@oracle.com> Cc: Leon Romanovsky <leon@kernel.org>; Santosh Shilimkar <santosh.shilimkar@oracle.com>; David S . Miller <davem@davemloft.net>; kuba@kernel.org; netdev@vger.kernel.org; linux-rdma@vger.kernel.org; rds-devel@oss.oracle.com; linux-kernel@vger.kernel.org; Rama Nichanamatlu <rama.nichanamatlu@oracle.com>; Rajesh Sivaramasubramaniom <rajesh.sivaramasubramaniom@oracle.com> Subject: Re: [PATCH RFC] rds: ib: Reduce the contention caused by the asynchronous workers to flush the mr pool
On Wed, Jan 19, 2022 at 11:46:16AM +0000, Praveen Kannoju wrote: > 6. Jason, the only function "rds_ib_free_mr" which accesses the > introduced bool variable "flush_ongoing" to spawn a flush worker does > not crucially impact the availability of MR's, because the flush > happens from allocation path as well when necessary. Hence the > Load-store ordering is not essentially needed here, because of which > we chose smp_rmb() and smp_wmb() over smp_load_acquire() and > smp_store_release().
That seems like a confusing statement, you added barriers which do the same things as acquire/release then say you didn't need acquire release?
I think this is using barriers wrong.
Jason
Jason,
Yes, we are using the barriers. I was justifying the usage of smp_rmb() and smp_wmb() over smp_load_acquire() and smp_store_release() in the patch.
| |