From: Richard Weinberger <richard@nod.at>
To: anton ivanov <anton.ivanov@cambridgegreys.com>
Cc: linux-um <linux-um@lists.infradead.org>
Subject: Re: [PATCH] um: allow using glibc string functions instead of generics
Date: Tue, 10 Nov 2020 22:29:53 +0100 (CET) [thread overview]
Message-ID: <1253718433.290759.1605043793706.JavaMail.zimbra@nod.at> (raw)
In-Reply-To: <ee2da9e0-2858-ef9c-b8b9-bdf569ec9bb4@cambridgegreys.com>
----- Ursprüngliche Mail -----
> Von: "anton ivanov" <anton.ivanov@cambridgegreys.com>
>> On what workload did you see such a huge performance improvement?
>
> File IO ~ 1% or thereabouts, iperf - 2-4%.
>
>> The in-kernel variants of memcpy and such are already well optimized.
>
> UML has no string.h in asm which means it falls back to
> asm-generic/string.h which in turn pulls in the ones from lib/string.c
>
> These are not optimized.
Hmmm, I think it should use the highly optimized variants from arch/x86.
Thanks,
//richard
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next prev parent reply other threads:[~2020-11-10 21:29 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-10 16:30 [PATCH] um: allow using glibc string functions instead of generics anton.ivanov
2020-11-10 16:40 ` Johannes Berg
2020-11-10 16:54 ` Anton Ivanov
2020-11-10 20:13 ` Richard Weinberger
2020-11-10 20:56 ` Anton Ivanov
2020-11-10 21:29 ` Richard Weinberger [this message]
2020-11-10 21:33 ` Anton Ivanov
2020-11-10 21:39 ` Richard Weinberger
2020-11-11 7:13 ` Anton Ivanov
2020-11-11 8:26 ` Anton Ivanov
2020-11-11 15:14 ` Anton Ivanov
2020-11-11 15:59 ` Anton Ivanov
2020-11-11 18:09 ` Anton Ivanov
2020-11-11 9:49 ` Anton Ivanov
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