From: Jan Hubicka <hubicka@ucw.cz>
To: Andi Kleen <ak@linux.intel.com>
Cc: 172060045@hdu.edu.cn, gcc <gcc@gcc.gnu.org>,
Eugene.Rozenfeld@microsoft.com
Subject: Re: State of AutoFDO in GCC
Date: Sun, 9 May 2021 19:01:21 +0200 [thread overview]
Message-ID: <20210509170121.GE25641@kam.mff.cuni.cz> (raw)
In-Reply-To: <7c802b11-857e-78eb-c2e8-0a3044817793@linux.intel.com>
>
> > With my tests, AutoFDO could achieve almost half of the effect of
> > instrumentation FDO on real applications such as MySQL 8.0.20 .
>
> Likely this could be improved with some of the missing changes. Apparently
> discriminator support is worth quite a bit especially on dense C++ code
> bases. Without that, gcc autofdo only works on line numbers, which can be
> very limiting if single lines have a lot of basic blocks.
>
> Sadly discriminator support is currently only on the old Google branch and
> not in gcc mainline
>
> Longer term it would probably be best to replace all this with some custom
> specialized binary annotation instead of stretching DWARF beyond its limits.
I think it makes sense to pick the AutoFDO to the lists of things that
would be nice to fix in GCC12. I guess first we need to solve the
issues with the tool producing autofdo gcda files and once that works
setup some benchmarking so we know how things compare to FDO and they
get tested.
If you point me to the discriminator patches I can try to figure out how
hard would be to mainline them. I am not too sure about custom
annotations though - storing info about regions of code segment is
always a pain and it is quite nice that dwarf provides support for that.
But I guess we could go step by step. I first need a working setup ;)
Honza
>
> -Andi
>
next prev parent reply other threads:[~2021-05-09 17:01 UTC|newest]
Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-22 19:58 Eugene Rozenfeld
2021-04-22 20:16 ` Martin Liška
2021-04-22 22:29 ` Jan Hubicka
2021-04-23 4:14 ` Xinliang David Li
2021-04-23 7:00 ` Richard Biener
2021-04-23 7:18 ` Martin Liška
2021-04-23 9:32 ` Richard Biener
2021-04-23 16:41 ` Xinliang David Li
2021-04-23 16:54 ` Jan Hubicka
2021-04-23 17:04 ` Xinliang David Li
2021-04-23 17:16 ` Jan Hubicka
2021-04-23 17:27 ` Xinliang David Li
2021-04-23 17:28 ` Xinliang David Li
2021-04-23 19:28 ` Jan Hubicka
2021-04-23 19:58 ` Xinliang David Li
2021-04-25 19:07 ` Jan Hubicka
2021-04-25 23:18 ` Xinliang David Li
2021-04-26 4:22 ` Wei Mi
2021-04-26 15:11 ` Andi Kleen
2021-04-26 16:57 ` Xinliang David Li
2021-04-26 18:00 ` Andi Kleen
2021-04-26 18:05 ` Xinliang David Li
2021-04-26 18:40 ` Hongtao Yu
2021-04-26 19:13 ` Andi Kleen
2021-04-29 5:40 ` Andi Kleen
2021-04-29 14:45 ` 172060045
2021-04-30 21:43 ` Andi Kleen
2021-05-08 11:25 ` 172060045
2021-05-09 16:28 ` Andi Kleen
2021-05-09 17:01 ` Jan Hubicka [this message]
2021-05-10 15:36 ` Andi Kleen
2021-05-10 16:55 ` Joseph Myers
2021-05-10 17:21 ` Andi Kleen
2022-07-26 20:12 ` Eugene Rozenfeld
2022-07-26 22:37 ` David Edelsohn
2022-07-27 7:26 ` Jan Hubicka
2022-07-27 18:30 ` [EXTERNAL] " Eugene Rozenfeld
2022-07-27 18:24 ` Eugene Rozenfeld
2022-07-27 1:31 ` Xionghu Luo
2022-07-27 1:41 ` Xionghu Luo
2022-07-27 18:38 ` [EXTERNAL] " Eugene Rozenfeld
2021-05-10 23:46 ` Wei Mi
2021-05-22 1:28 ` [EXTERNAL] " Eugene Rozenfeld
2021-05-22 16:36 ` Wei Mi
2021-05-25 1:39 ` Eugene Rozenfeld
2021-05-25 3:11 ` Wei Mi
2021-05-25 3:33 ` Eugene Rozenfeld
2021-05-25 3:54 ` Wei Mi
2021-05-25 7:01 ` Eugene Rozenfeld
2021-05-25 16:16 ` Wei Mi
2021-05-25 20:49 ` Eugene Rozenfeld
2021-05-26 3:06 ` Wei Mi
2021-05-26 23:39 ` Eugene Rozenfeld
2021-05-27 2:51 ` Wei Mi
2021-06-12 1:14 ` Eugene Rozenfeld
2021-06-14 17:00 ` Wei Mi
2021-04-23 17:20 ` Jan Hubicka
2021-04-23 16:36 ` Xinliang David Li
2021-04-30 18:48 ` [EXTERNAL] " Eugene Rozenfeld
2021-04-30 21:45 ` Andi Kleen
2021-06-24 21:45 ` Eugene Rozenfeld
2021-04-23 1:46 ` Bin.Cheng
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