Subject: Re: [PATCH v3 03/16] index-helper: new daemon for caching index and related stuff

From: Johannes Sixt <[email-masked]>
Date: Thu, 7 Apr 2016 08:21:13 +0200

Am 07.04.2016 um 00:11 schrieb David Turner:
> +static void share_index(struct index_state *istate, struct shm *is)
> +{
> +	void *new_mmap;
> +	if (istate->mmap_size <= 20 ||
> +	    hashcmp(istate->sha1,
> +		    (unsigned char *)istate->mmap + istate->mmap_size - 20) ||
> +	    !hashcmp(istate->sha1, is->sha1) ||
> +	    git_shm_map(O_CREAT | O_EXCL | O_RDWR, 0700, istate->mmap_size,
> +			&new_mmap, PROT_READ | PROT_WRITE, MAP_SHARED,
> +			"git-index-%s", sha1_to_hex(istate->sha1)) < 0)

Builds which have NO_MMAP set require that MAP_PRIVATE is set. So I 
would guess that at this point you leave those builds behind. Unless we 
declare such systems as hopelessly outdated and remove NO_MMAP and 
compat/mmap.c or you support index-helper only when NO_MMAP is not set.

-- Hannes