From: "Cohen, Eugene" <eugene@hp.com>
To: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: "edk2-devel@lists.01.org" <edk2-devel@lists.01.org>,
"leif.lindholm@linaro.org" <leif.lindholm@linaro.org>,
"liming.gao@intel.com" <liming.gao@intel.com>
Subject: Re: [PATCH 1/3] ArmPkg/CompilerIntrinsicsLib: replace memcpy and memset with C code
Date: Thu, 11 Aug 2016 21:50:20 +0000 [thread overview]
Message-ID: <AT5PR84MB029157C951664077DEE207ABB41E0@AT5PR84MB0291.NAMPRD84.PROD.OUTLOOK.COM> (raw)
In-Reply-To: <CAKv+Gu82Nx7MT7nkw2yTBMt67BBDOD=pqmOjw-eiNwb25zk3iQ@mail.gmail.com>
> > Why does memcpy performance matter? In addition to the overall
> memcpy stuff scattered around C code we have an instance that is
> particularly sensitive to memcpy performance. For DMA operations
> when invoking double-buffering or access to portions of a buffer that
> is common mapped (i.e. uncached on non-coherent DMA systems) the
> impact of a non-optimized memcpy is enormous compared to the
> optimized ones because the penalty is amplified by orders of
> magnitude due to uncached memory access latency.
> >
>
> That code would be using CopyMem(), no? This only serves the
> compiler
> generated calls, which are few since Tianocore does not allow
> initialized locals.
I see and agree that should minimize the impact. I guess I'll ask the naive question. Could the BaseMemoryLib and CompilerIntrinsicsLib share the same stuff?
next prev parent reply other threads:[~2016-08-11 21:50 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-11 18:20 [PATCH 1/3] ArmPkg/CompilerIntrinsicsLib: replace memcpy and memset with C code Ard Biesheuvel
2016-08-11 18:20 ` [PATCH 2/3] BaseTools RVCT: ignore various RVC diagnostics Ard Biesheuvel
2016-08-12 3:04 ` Gao, Liming
2016-08-11 18:20 ` [PATCH 3/3] MdePkg RVCT: add definition of UNREACHABLE Ard Biesheuvel
2016-08-12 3:04 ` Gao, Liming
2016-08-11 21:34 ` [PATCH 1/3] ArmPkg/CompilerIntrinsicsLib: replace memcpy and memset with C code Cohen, Eugene
2016-08-11 21:45 ` Ard Biesheuvel
2016-08-11 21:50 ` Cohen, Eugene [this message]
2016-08-11 21:53 ` Ard Biesheuvel
2016-08-11 23:04 ` Andrew Fish
2016-08-12 8:09 ` Ard Biesheuvel
2016-09-01 13:11 ` Leif Lindholm
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-list 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=AT5PR84MB029157C951664077DEE207ABB41E0@AT5PR84MB0291.NAMPRD84.PROD.OUTLOOK.COM \
--to=devel@edk2.groups.io \
/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