From: Dmitry Vyukov <dvyukov@google.com>
To: Andi Kleen <andi@firstfloor.org>
Cc: zengzhaoxiu@163.com, Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
Denys Vlasenko <dvlasenk@redhat.com>,
bp@suse.de, Andrew Morton <akpm@linux-foundation.org>,
Kees Cook <keescook@chromium.org>,
LKML <linux-kernel@vger.kernel.org>,
Zhaoxiu Zeng <zhaoxiu.zeng@gmail.com>
Subject: Re: [PATCH v2 10/30] Add x86-specific parity functions
Date: Thu, 7 Apr 2016 08:31:09 +0200 [thread overview]
Message-ID: <CACT4Y+ZGbzTJj5G1EYW6fcuHxEB8NezfzB9nKBgtBEETpGPtHQ@mail.gmail.com> (raw)
In-Reply-To: <87wpoay10o.fsf@tassilo.jf.intel.com>
On Wed, Apr 6, 2016 at 9:45 PM, Andi Kleen <andi@firstfloor.org> wrote:
> zengzhaoxiu@163.com writes:
>
>> From: Zhaoxiu Zeng <zhaoxiu.zeng@gmail.com>
>>
>> Use alternatives, lifted from arch_hweight
>
> Is there actually anything performance critical in the kernel that uses
> parity?
>
> FWIW the arch hweight custom calling convention is a problem for LTO
> because it needs different special flags, so I usually have to disable
> it. Likely other reasonable usages, such as automatic source code
> analysis, and other tool chain based usages have similar problems.
>
> As far as I can tell both for hweight and likely for parity it is
> badly overengineering and normal calling conventions would work as well,
> and cause much less problems.
>
> So if parity is really worth adding here (which I find doubtful,
> but you may have numbers), please add it without these magic
> calling hacks.
Hweight custom calling convention caused crashes with KCOV coverage.
We had to disable instrumentation of the file.
next prev parent reply other threads:[~2016-04-07 6:31 UTC|newest]
Thread overview: 84+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-05 2:06 [PATCH V2 01/30] bitops: add parity functions Zeng Zhaoxiu
2016-04-05 4:23 ` [PATCH V2 02/30] Include generic parity.h in some architectures' bitops.h Zeng Zhaoxiu
2016-04-06 8:41 ` [PATCH v2 " zengzhaoxiu
2016-04-05 19:04 ` [PATCH V2 01/30] bitops: add parity functions Sam Ravnborg
2016-04-06 5:33 ` Zeng Zhaoxiu
2016-04-06 8:24 ` Sam Ravnborg
2016-04-06 8:22 ` [PATCH v2 " zengzhaoxiu
2016-04-06 8:46 ` [PATCH v2 03/30] Add alpha-specific " zengzhaoxiu
2016-04-06 8:53 ` [PATCH v2 04/30] Add blackfin-specific " zengzhaoxiu
2016-04-06 8:57 ` [PATCH v2 05/30] Add ia64-specific " zengzhaoxiu
2016-04-06 8:59 ` [PATCH v2 06/30] Add mips-specific " zengzhaoxiu
2016-04-06 10:23 ` zengzhaoxiu
2016-04-06 9:03 ` [PATCH v2 07/30] Add powerpc-specific " zengzhaoxiu
2016-04-06 9:07 ` [PATCH v2 08/30] Add sparc-specific " zengzhaoxiu
2016-04-06 18:44 ` Sam Ravnborg
2016-04-07 3:56 ` Zeng Zhaoxiu
2016-04-06 9:08 ` [PATCH v2 09/30] Add tile-specific " zengzhaoxiu
2016-04-06 13:27 ` Chris Metcalf
2016-04-07 3:55 ` Zeng Zhaoxiu
2016-04-06 9:14 ` [PATCH v2 10/30] Add x86-specific " zengzhaoxiu
2016-04-06 10:13 ` Borislav Petkov
2016-04-06 10:37 ` One Thousand Gnomes
2016-04-06 10:53 ` Borislav Petkov
2016-04-07 3:55 ` Zeng Zhaoxiu
2016-04-07 9:39 ` Borislav Petkov
2016-04-11 2:43 ` Zeng Zhaoxiu
2016-04-15 2:11 ` Borislav Petkov
2016-04-07 3:55 ` Zeng Zhaoxiu
2016-04-07 9:41 ` Borislav Petkov
2016-04-06 19:45 ` Andi Kleen
2016-04-07 3:56 ` Zeng Zhaoxiu
2016-04-07 6:31 ` Dmitry Vyukov [this message]
2016-04-07 9:43 ` Borislav Petkov
2016-05-04 18:46 ` [RFC PATCH] x86/hweight: Get rid of the special calling convention Borislav Petkov
2016-05-04 19:31 ` Brian Gerst
2016-05-04 19:33 ` H. Peter Anvin
2016-05-04 19:41 ` Borislav Petkov
2016-05-04 19:49 ` H. Peter Anvin
2016-05-04 20:22 ` Borislav Petkov
2016-05-04 20:51 ` H. Peter Anvin
2016-05-04 21:09 ` Andi Kleen
2016-05-05 13:02 ` Denys Vlasenko
2016-05-05 14:04 ` Borislav Petkov
2016-05-10 16:53 ` [PATCH -v2] " Borislav Petkov
2016-05-10 17:23 ` Peter Zijlstra
2016-05-10 19:02 ` Borislav Petkov
2016-05-10 19:03 ` H. Peter Anvin
2016-05-10 19:10 ` Borislav Petkov
2016-05-10 22:30 ` H. Peter Anvin
2016-05-11 4:11 ` Borislav Petkov
2016-05-11 11:15 ` Brian Gerst
2016-05-11 11:24 ` Peter Zijlstra
2016-05-11 12:47 ` Borislav Petkov
2016-05-12 4:54 ` H. Peter Anvin
2016-05-12 11:57 ` Borislav Petkov
2016-05-12 12:14 ` Peter Zijlstra
2016-05-12 13:09 ` Borislav Petkov
2016-05-18 10:38 ` Borislav Petkov
2016-04-07 14:10 ` [PATCH v2 10/30] Add x86-specific parity functions One Thousand Gnomes
2016-04-06 9:27 ` [PATCH v2 11/30] sunrpc: use parity8 zengzhaoxiu
2016-04-06 9:30 ` [PATCH v2 12/30] mips: use parity functions in cerr-sb1.c zengzhaoxiu
2016-04-06 9:36 ` [PATCH v2 13/30] bch: use parity32 zengzhaoxiu
2016-04-06 9:39 ` [PATCH v2 14/30] media: use parity8 in vivid-vbi-gen.c zengzhaoxiu
2016-04-06 9:41 ` [PATCH v2 15/30] media: use parity functions in saa7115 zengzhaoxiu
2016-04-06 9:43 ` [PATCH v2 16/30] input: use parity32 in grip_mp zengzhaoxiu
2016-04-06 9:44 ` [PATCH v2 17/30] input: use parity64 in sidewinder zengzhaoxiu
2016-04-06 9:45 ` [PATCH v2 18/30] input: use parity16 in ams_delta_serio zengzhaoxiu
2016-04-06 9:47 ` [PATCH v2 19/30] scsi: use parity32 in isci's phy zengzhaoxiu
2016-04-06 9:52 ` [PATCH v2 20/30] mtd: use parity16 in ssfdc zengzhaoxiu
2016-04-06 9:53 ` [PATCH v2 21/30] mtd: use parity functions in inftlcore zengzhaoxiu
2016-04-06 9:58 ` [PATCH v2 22/30] crypto: use parity functions in qat_hal zengzhaoxiu
2016-04-06 10:05 ` [PATCH v2 23/30] mtd: use parity16 in sm_ftl zengzhaoxiu
2016-04-06 10:11 ` [PATCH v2 24/30] ethernet: use parity8 in sun/niu.c zengzhaoxiu
2016-04-06 10:14 ` [PATCH v2 25/30] input: use parity8 in pcips2 zengzhaoxiu
2016-04-06 10:15 ` [PATCH v2 26/30] input: use parity8 in sa1111ps2 zengzhaoxiu
2016-04-06 10:16 ` [PATCH v2 27/30] iio: use parity32 in adxrs450 zengzhaoxiu
2016-04-10 14:37 ` Jonathan Cameron
2016-04-10 14:41 ` Lars-Peter Clausen
2016-04-10 15:13 ` Jonathan Cameron
2016-04-10 15:14 ` Jonathan Cameron
2016-04-06 10:18 ` [PATCH v2 28/30] serial: use parity32 in max3100 zengzhaoxiu
2016-04-06 10:25 ` Greg KH
2016-04-06 10:20 ` [PATCH v2 29/30] input: use parity8 in elantech zengzhaoxiu
2016-04-06 10:21 ` [PATCH v2 30/30] ethernet: use parity8 in broadcom/tg3.c zengzhaoxiu
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