Messages in this thread |  | | Subject | Re: [PATCH] x86/usercopy: speed up 64-bit __clear_user() with stos{b,q} | From | Andi Kleen <> | Date | Sun, 23 May 2021 20:43:54 -0700 |
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On 5/23/2021 11:04 AM, Samuel Neves wrote: > The > This change is noticeable from userspace. That is in fact how I spotted it; in > a hashing benchmark that read from /dev/zero, around 10-15% of the CPU time > was spent in __clear_user. After this patch, on a Skylake CPU, these are the > before/after figures: > > $ dd if=/dev/zero of=/dev/null bs=1024k status=progress > 94402248704 bytes (94 GB, 88 GiB) copied, 6 s, 15.7 GB/s
The question is of course if this actually represents any real workload.
-Andi
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