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Re: [PATCH v3] Make fprintf() function to multithread-safe

From: Andreas Jaeger <aj at suse dot com>
To: libc-alpha at sourceware dot org
Cc: Peng Haitao <penght at cn dot fujitsu dot com>
Date: Tue, 24 Jul 2012 16:05:05 +0200
Subject: Re: [PATCH v3] Make fprintf() function to multithread-safe
References: <1340257789-14975-1-git-send-email-penght@cn.fujitsu.com> <CADZpyizABs-q_FC+KurnsxPKq4dW=AVTefc0EEwBFh6=E6T5dw@mail.gmail.com> <500E5094.2080203@cn.fujitsu.com>

On Tuesday, July 24, 2012 15:36:52 Peng Haitao wrote:
> [...]
> >  Performance counter stats for './fprintf':
> 
>     30,029,273,153 instructions              #    0.00  insns per
> cycle
> 
>        7.533755240 seconds time elapsed
> [...]
> # perf stat -e instructions -- ./fprintf_new > /dev/null
> 
>  Performance counter stats for './fprintf_new':
> 
>     39,694,838,263 instructions              #    0.00  insns per
> cycle
> 
>        9.690116102 seconds time elapsed

So, the overhead is in this case 25 per cent? That's a lot IMO.

Andreas
-- 
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References:
- Re: [PATCH v3] Make fprintf() function to multithread-safe
  - From: Carlos O'Donell
- Re: [PATCH v3] Make fprintf() function to multithread-safe
  - From: Peng Haitao

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