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From: Jens Axboe <axboe@kernel.dk>
To: Linus Torvalds <torvalds@linux-foundation.org>,
	kernel test robot <oliver.sang@intel.com>
Cc: David Howells <dhowells@redhat.com>,
	lkp@lists.01.org, kernel test robot <lkp@intel.com>,
	"Huang, Ying" <ying.huang@intel.com>,
	Feng Tang <feng.tang@intel.com>,
	zhengjun.xing@intel.com, Pavel Begunkov <asml.silence@gmail.com>,
	Matthew Wilcox <willy@infradead.org>,
	Alexander Viro <viro@zeniv.linux.org.uk>,
	linux-fsdevel <linux-fsdevel@vger.kernel.org>,
	linux-block <linux-block@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [iov_iter] 9bd0e337c6: will-it-scale.per_process_ops -4.8% regression
Date: Thu, 3 Dec 2020 10:50:03 -0700	[thread overview]
Message-ID: <8124ce0d-c934-0771-5e34-cf5ea030fc08@kernel.dk> (raw)
In-Reply-To: <CAHk-=wif1iGLiqcsx1YdLS4tN01JuH-MV_oem0duHqskhDTY9A@mail.gmail.com>

On 12/3/20 10:47 AM, Linus Torvalds wrote:
> On Wed, Dec 2, 2020 at 10:31 PM kernel test robot <oliver.sang@intel.com> wrote:
>>
>> FYI, we noticed a -4.8% regression of will-it-scale.per_process_ops due to commit:
> 
> Ok, I guess that's bigger than expected, but the profile data does
> show how bad the indirect branches are.

It's also in the same range (3-6%) as the microbenchmarks I ran and posted.
So at least there's correlation there too.

-- 
Jens Axboe


  reply	other threads:[~2020-12-03 17:51 UTC|newest]

Thread overview: 55+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-21 14:13 [PATCH 00/29] RFC: iov_iter: Switch to using an ops table David Howells
2020-11-21 14:13 ` [PATCH 01/29] iov_iter: Switch to using a table of operations David Howells
2020-11-21 14:31   ` Pavel Begunkov
2020-11-23 23:21     ` Pavel Begunkov
2020-11-21 18:21   ` Linus Torvalds
2020-12-11  1:30     ` Al Viro
2020-11-22 13:33   ` David Howells
2020-11-22 13:58     ` David Laight
2020-11-22 19:22     ` Linus Torvalds
2020-11-22 22:34       ` David Laight
2020-11-22 22:46   ` David Laight
2020-11-23  8:05   ` Christoph Hellwig
2020-11-23 10:31   ` David Howells
2020-11-23 23:42     ` Pavel Begunkov
2020-11-24 12:50     ` David Howells
2020-11-24 15:30       ` Jens Axboe
2020-11-27 17:14       ` David Howells
2020-11-23 11:14   ` David Howells
     [not found]   ` <20201203064536.GE27350@xsang-OptiPlex-9020>
2020-12-03 17:47     ` [iov_iter] 9bd0e337c6: will-it-scale.per_process_ops -4.8% regression Linus Torvalds
2020-12-03 17:50       ` Jens Axboe [this message]
2020-12-04 11:50     ` David Howells
2020-12-04 11:51     ` David Howells
2020-12-07 13:10       ` Oliver Sang
2020-12-07 13:20       ` David Howells
2020-11-21 14:13 ` [PATCH 02/29] iov_iter: Split copy_page_to_iter() David Howells
2020-11-21 14:13 ` [PATCH 03/29] iov_iter: Split iov_iter_fault_in_readable David Howells
2020-11-21 14:13 ` [PATCH 04/29] iov_iter: Split the iterate_and_advance() macro David Howells
2020-11-21 14:14 ` [PATCH 05/29] iov_iter: Split copy_to_iter() David Howells
2020-11-21 14:14 ` [PATCH 06/29] iov_iter: Split copy_mc_to_iter() David Howells
2020-11-21 14:14 ` [PATCH 07/29] iov_iter: Split copy_from_iter() David Howells
2020-11-21 14:14 ` [PATCH 08/29] iov_iter: Split the iterate_all_kinds() macro David Howells
2020-11-21 14:14 ` [PATCH 09/29] iov_iter: Split copy_from_iter_full() David Howells
2020-11-21 14:14 ` [PATCH 10/29] iov_iter: Split copy_from_iter_nocache() David Howells
2020-11-21 14:14 ` [PATCH 11/29] iov_iter: Split copy_from_iter_flushcache() David Howells
2020-11-21 14:14 ` [PATCH 12/29] iov_iter: Split copy_from_iter_full_nocache() David Howells
2020-11-21 14:15 ` [PATCH 13/29] iov_iter: Split copy_page_from_iter() David Howells
2020-11-21 14:15 ` [PATCH 14/29] iov_iter: Split iov_iter_zero() David Howells
2020-11-21 14:15 ` [PATCH 15/29] iov_iter: Split copy_from_user_atomic() David Howells
2020-11-21 14:15 ` [PATCH 16/29] iov_iter: Split iov_iter_advance() David Howells
2020-11-21 14:15 ` [PATCH 17/29] iov_iter: Split iov_iter_revert() David Howells
2020-11-21 14:15 ` [PATCH 18/29] iov_iter: Split iov_iter_single_seg_count() David Howells
2020-11-21 14:15 ` [PATCH 19/29] iov_iter: Split iov_iter_alignment() David Howells
2020-11-21 14:15 ` [PATCH 20/29] iov_iter: Split iov_iter_gap_alignment() David Howells
2020-11-21 14:16 ` [PATCH 21/29] iov_iter: Split iov_iter_get_pages() David Howells
2020-11-21 14:16 ` [PATCH 22/29] iov_iter: Split iov_iter_get_pages_alloc() David Howells
2020-11-21 14:16 ` [PATCH 23/29] iov_iter: Split csum_and_copy_from_iter() David Howells
2020-11-21 14:16 ` [PATCH 24/29] iov_iter: Split csum_and_copy_from_iter_full() David Howells
2020-11-21 14:16 ` [PATCH 25/29] iov_iter: Split csum_and_copy_to_iter() David Howells
2020-11-21 14:16 ` [PATCH 26/29] iov_iter: Split iov_iter_npages() David Howells
2020-11-21 14:16 ` [PATCH 27/29] iov_iter: Split dup_iter() David Howells
2020-11-21 14:17 ` [PATCH 28/29] iov_iter: Split iov_iter_for_each_range() David Howells
2020-11-21 14:17 ` [PATCH 29/29] iov_iter: Remove iterate_all_kinds() and iterate_and_advance() David Howells
2020-11-21 14:34 ` [PATCH 00/29] RFC: iov_iter: Switch to using an ops table Pavel Begunkov
2020-11-21 18:23 ` Linus Torvalds
2020-12-11  3:24 ` Matthew Wilcox

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