From: Ingo Molnar <mingo@kernel.org>
To: mark.rutland@arm.com, tglx@linutronix.de, hpa@zytor.com,
linux-kernel@vger.kernel.org, peterz@infradead.org,
boqun.feng@gmail.com, will.deacon@arm.com
Cc: linux-tip-commits@vger.kernel.org
Subject: Re: [tip:locking/core] locking/atomics: Check generated headers are up-to-date
Date: Wed, 21 Nov 2018 09:02:58 +0100 [thread overview]
Message-ID: <20181121080258.GA56691@gmail.com> (raw)
In-Reply-To: <tip-8d32588077bdc390420cfa6946f407033a20d7a8@git.kernel.org>
* tip-bot for Mark Rutland <tipbot@zytor.com> wrote:
> Commit-ID: 8d32588077bdc390420cfa6946f407033a20d7a8
> Gitweb: https://git.kernel.org/tip/8d32588077bdc390420cfa6946f407033a20d7a8
> Author: Mark Rutland <mark.rutland@arm.com>
> AuthorDate: Tue, 4 Sep 2018 11:48:29 +0100
> Committer: Ingo Molnar <mingo@kernel.org>
> CommitDate: Thu, 1 Nov 2018 11:01:10 +0100
>
> locking/atomics: Check generated headers are up-to-date
>
> Now that all the generated atomic headers are in place, it would be good
> to ensure that:
>
> a) the headers are up-to-date when scripting changes.
>
> b) developers don't directly modify the generated headers.
>
> To ensure both of these properties, let's add a Kbuild step to check
> that the generated headers are up-to-date.
>
> Signed-off-by: Mark Rutland <mark.rutland@arm.com>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> Cc: linux-arm-kernel@lists.infradead.org
> Cc: catalin.marinas@arm.com
> Cc: Will Deacon <will.deacon@arm.com>
> Cc: linuxdrivers@attotech.com
> Cc: dvyukov@google.com
> Cc: Boqun Feng <boqun.feng@gmail.com>
> Cc: arnd@arndb.de
> Cc: aryabinin@virtuozzo.com
> Cc: glider@google.com
> Link: http://lkml.kernel.org/r/20180904104830.2975-6-mark.rutland@arm.com
> Signed-off-by: Ingo Molnar <mingo@kernel.org>
> ---
> Kbuild | 18 ++++++++++++++++--
> scripts/atomic/check-atomics.sh | 19 +++++++++++++++++++
> 2 files changed, 35 insertions(+), 2 deletions(-)
These scripts are *awfully* slow to be run at every kernel build - even a
reasonably fast machine:
model name : Intel(R) Xeon(R) CPU E5-2680 v2 @ 2.80GHz
... they are adding 3-4 seconds to the build time:
[Before]:
galatea:~/linux/linux> perf stat --null --repeat 3 make kernel/sched/core.o
CALL scripts/checksyscalls.sh
DESCEND objtool
CALL scripts/checksyscalls.sh
DESCEND objtool
CALL scripts/checksyscalls.sh
DESCEND objtool
Performance counter stats for 'make kernel/sched/core.o' (3 runs):
1.201874 +- 0.000371 seconds time elapsed ( +- 0.03% )
[After]:
galatea:~/linux/linux> perf stat --null --repeat 3 make kernel/sched/core.o
CALL scripts/checksyscalls.sh
CALL scripts/atomic/check-atomics.sh
DESCEND objtool
CALL scripts/checksyscalls.sh
CALL scripts/atomic/check-atomics.sh
DESCEND objtool
CALL scripts/checksyscalls.sh
CALL scripts/atomic/check-atomics.sh
DESCEND objtool
Performance counter stats for 'make kernel/sched/core.o' (3 runs):
4.5987 +- 0.0109 seconds time elapsed ( +- 0.24% )
Could we please get this fixed so that proper dependencies are checked
and it's only regenerated when needed? This slowdown makes additive-build
kernel development quite painful, as ~5 seconds is in the 'too long'
category already, while 1.2 seconds is basically instantaneous.
I cannot even imagine the slowdown on a truly slow box where kernel
development *has* to be additive.
Thanks,
Ingo
next prev parent reply other threads:[~2018-11-21 8:03 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-04 10:48 [PATCHv3 0/6] atomics: generate atomic headers / instrument arm64 Mark Rutland
2018-09-04 10:48 ` [PATCHv3 1/6] atomics: add common header generation files Mark Rutland
2018-11-01 9:54 ` [tip:locking/core] locking/atomics: Add " tip-bot for Mark Rutland
2018-11-01 10:06 ` tip-bot for Mark Rutland
2018-11-15 23:03 ` [PATCHv3 1/6] atomics: add " Andrew Morton
2018-11-15 23:10 ` Andrew Morton
2018-11-16 2:51 ` Mark Rutland
2018-11-21 22:34 ` Andrew Morton
2018-09-04 10:48 ` [PATCHv3 2/6] atomics: switch to generated fallbacks Mark Rutland
2018-11-01 9:55 ` [tip:locking/core] locking/atomics: Switch " tip-bot for Mark Rutland
2018-11-01 10:07 ` tip-bot for Mark Rutland
2018-09-04 10:48 ` [PATCHv3 3/6] atomics: switch to generated atomic-long Mark Rutland
2018-11-01 9:55 ` [tip:locking/core] locking/atomics: Switch " tip-bot for Mark Rutland
2018-11-01 10:08 ` tip-bot for Mark Rutland
2018-09-04 10:48 ` [PATCHv3 4/6] atomics: switch to generated instrumentation Mark Rutland
2018-11-01 9:56 ` [tip:locking/core] locking/atomics: Switch " tip-bot for Mark Rutland
2018-11-01 10:08 ` tip-bot for Mark Rutland
2018-09-04 10:48 ` [PATCHv3 5/6] atomics: check generated headers are up-to-date Mark Rutland
2018-11-01 9:57 ` [tip:locking/core] locking/atomics: Check " tip-bot for Mark Rutland
2018-11-01 10:09 ` tip-bot for Mark Rutland
2018-11-21 8:02 ` Ingo Molnar [this message]
2018-11-21 11:40 ` Mark Rutland
2018-11-28 8:30 ` Ingo Molnar
2018-09-04 10:48 ` [PATCHv3 6/6] arm64: use instrumented atomics Mark Rutland
2018-11-01 9:57 ` [tip:locking/core] arm64: Use " tip-bot for Mark Rutland
2018-11-01 10:09 ` [tip:locking/core] arm64, locking/atomics: " tip-bot for Mark Rutland
2018-10-08 17:15 ` [PATCHv3 0/6] atomics: generate atomic headers / instrument arm64 Mark Rutland
2018-10-19 10:27 ` Will Deacon
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20181121080258.GA56691@gmail.com \
--to=mingo@kernel.org \
--cc=boqun.feng@gmail.com \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-tip-commits@vger.kernel.org \
--cc=mark.rutland@arm.com \
--cc=peterz@infradead.org \
--cc=tglx@linutronix.de \
--cc=will.deacon@arm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).