From: Christian Holtje <docwhat@gmail.com>
Date: Fri, 27 Jun 2008 13:54:10 GMT
Subject: Re: pread() over NFS (again) [1.5.5.4]
Message-ID: <590C8EE3-B909-4EE5-8EFA-F5B9031A8C05@gmail.com>
In-Reply-To: <65688C06-BB6A-4E95-A4B9-A1A7C206BE2E@sent.com>

On Jun 26, 2008, at 7:36 PM, logank@sent.com wrote:
> diff --git a/index-pack.c b/index-pack.c
> index 5ac91ba..85c8bdb 100644
> --- a/index-pack.c
> +++ b/index-pack.c
> @@ -313,7 +313,14 @@ static void *get_data_from_pack(struct  
> object_entry *obj)
> 	src = xmalloc(len);
> 	data = src;
> 	do {
> +		// It appears that if multiple threads read across NFS, the
> +		// second read will fail. I know this is awful, but we wait for
> +		// a little bit and try again.
> 		ssize_t n = pread(pack_fd, data + rdy, len - rdy, from + rdy);
> +		if (n <= 0) {
> +			sleep(1);
> +			n = pread(pack_fd, data + rdy, len - rdy, from + rdy);
> +		}
> 		if (n <= 0)
> 			die("cannot pread pack file: %s", strerror(errno));
> 		rdy += n;

This does work.  But the "unpacking objects" phase becomes very slow.   
I had 86 objects and I could see every time it did a sleep because the  
counter would wait a second (or more) before the next object was  
unpacked.

Ciao!