Re: [PATCH] block:Remove extra condition in end of disk check

[Raghavendra K T]

CCing more relevant people (with the help of get_maintainer --git-blame)

On 06/23/2013 10:47 PM, Raghavendra K T wrote:
> From: Raghavendra K T <raghavendra.kt@xxxxxxxxxxxxxxxxxx>
>
> Since #sector is always positive the reduced condition check
> encompasses maxsector < nr_sectors check.
>
> Signed-off-by: Raghavendra K T <raghavendra.kt@xxxxxxxxxxxxxxxxxx>
> ---
> An userspace program looping with:
> maxsector - 0-9999
> nr_sector - 0-999
> sector - 0-999 gave 6.4% improvement with new condition though I agree that
> it is not the best way to test it perhaps :)
>
> diff --git a/block/blk-core.c b/block/blk-core.c
> index 33c33bc..4a78583 100644
> --- a/block/blk-core.c
> +++ b/block/blk-core.c
> @@ -1656,7 +1656,7 @@ static inline int bio_check_eod(struct bio *bio, unsigned int nr_sectors)
>   	if (maxsector) {
>   		sector_t sector = bio->bi_sector;
>
> -		if (maxsector < nr_sectors || maxsector - nr_sectors < sector) {
> +		if (maxsector - nr_sectors < sector) {
>   			/*
>   			 * This may well happen - the kernel calls bread()
>   			 * without checking the size of the device, e.g., when

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