Re: [PATCH] libxl: stop libxl_domain_info() consuming massive amounts of stack

From: Ian Jackson <ian.jackson@citrix.com>
To: Paul Durrant <paul@xen.org>
Cc: Anthony Perard <anthony.perard@citrix.com>,
	"xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>,
	Paul Durrant <pdurrant@amazon.com>, Wei Liu <wl@xen.org>
Subject: Re: [PATCH] libxl: stop libxl_domain_info() consuming massive amounts of stack
Date: Thu, 28 May 2020 15:56:53 +0100	[thread overview]
Message-ID: <24271.53557.114994.926329@mariner.uk.xensource.com> (raw)
In-Reply-To: <20200528114801.20241-1-paul@xen.org>

Paul Durrant writes ("[PATCH] libxl: stop libxl_domain_info() consuming massive amounts of stack"):
> From: Paul Durrant <pdurrant@amazon.com>
> 
> Currently an array of 1024 xc_domaininfo_t is declared on stack. That alone
> consumes ~112k.

Wow.

> Since libxl_domain_info() creates a new gc this patch simply
> uses it to allocate the array instead.

Thanks.

> +    info = libxl__calloc(gc, 1024, sizeof(*info));

Wy not GCNEW_ARRAY ?

That avoids a possible bug with wrong number of * to sizeof (although
in this case you seem to have it right...)

Thanks,
Ian.