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SubjectRe: [Bench] New benchmark showing fileserver problem in 2.4.12
On Thu, 18 Oct 2001, Roger Larsson wrote:

>On Thursday 18 October 2001 04:01, Leo Mauro wrote:
>> Small fix to Linus's sample code
>>
>> unsigned int so_far = 0;
>> for (;;) {
>> int bytes = read(in, buf+so_far, BUFSIZE-so_far);
>> if (bytes <= 0)
>> break;
>> so_far += bytes;
>> if (so_far < BUFSIZE)
>> continue;
>> write(out, buf, BUFSIZE);
>> - so_far = 0;
>> + so_far -= BUFSIZE;
>> }
>> if (so_far)
>> write(out, buf, so_far);
>>
>> to avoid losing data.
>
>I was close to press the send button but noticed the "BUFSIZE-so_far"
>in the read call, just in time(TM).
>
>If it had not been there you would have needed to copy data from the
>end of buf (from above BUFSIZE) to the beginning of buf too...
>(the required size of buf would have been 2*BUFSIZE)

Since you only ever have BUFSIZE bytes when you write, aren't:

so_far -= BUFSIZE;

and

so_far = 0;

identical? I'd say the assignment to 0 would be faster.

--
George Greer, greerga@m-l.org
http://www.m-l.org/~greerga/

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