Re: [PATCH v2 8/9] util/mmap-alloc: Support RAM_NORESERVE via MAP_NORESERVE

Hi David, On Mon, Mar 8, 2021 at 10:45 AM David Hildenbrand wrote: > On 07.03.21 15:11, Marcel Apfelbaum wrote: > > Hi David, > > > > On Sun, Mar 7, 2021 at 3:18 PM David Hildenbrand > > wrote: > > > > On 05.03.21 16:51, Peter Xu wrote: > > > On Fri, Mar 05, 20

Re: [PATCH v2 8/9] util/mmap-alloc: Support RAM_NORESERVE via MAP_NORESERVE

On 07.03.21 15:11, Marcel Apfelbaum wrote: Hi David, On Sun, Mar 7, 2021 at 3:18 PM David Hildenbrand > wrote: On 05.03.21 16:51, Peter Xu wrote: > On Fri, Mar 05, 2021 at 04:44:36PM +0100, David Hildenbrand wrote: >> On 05.03.21 16:42, Peter Xu wrote:

Re: [PATCH v2 8/9] util/mmap-alloc: Support RAM_NORESERVE via MAP_NORESERVE

Hi David, On Sun, Mar 7, 2021 at 3:18 PM David Hildenbrand wrote: > On 05.03.21 16:51, Peter Xu wrote: > > On Fri, Mar 05, 2021 at 04:44:36PM +0100, David Hildenbrand wrote: > >> On 05.03.21 16:42, Peter Xu wrote: > >>> On Fri, Mar 05, 2021 at 11:16:33AM +0100, David Hildenbrand wrote: > +#

Re: [PATCH v2 8/9] util/mmap-alloc: Support RAM_NORESERVE via MAP_NORESERVE

On 05.03.21 16:51, Peter Xu wrote: On Fri, Mar 05, 2021 at 04:44:36PM +0100, David Hildenbrand wrote: On 05.03.21 16:42, Peter Xu wrote: On Fri, Mar 05, 2021 at 11:16:33AM +0100, David Hildenbrand wrote: +#define OVERCOMMIT_MEMORY_PATH "/proc/sys/vm/overcommit_memory" +static bool map_noreserv

Re: [PATCH v2 8/9] util/mmap-alloc: Support RAM_NORESERVE via MAP_NORESERVE

On 05.03.21 16:51, Peter Xu wrote: On Fri, Mar 05, 2021 at 04:44:36PM +0100, David Hildenbrand wrote: On 05.03.21 16:42, Peter Xu wrote: On Fri, Mar 05, 2021 at 11:16:33AM +0100, David Hildenbrand wrote: +#define OVERCOMMIT_MEMORY_PATH "/proc/sys/vm/overcommit_memory" +static bool map_noreserv

Re: [PATCH v2 8/9] util/mmap-alloc: Support RAM_NORESERVE via MAP_NORESERVE

On Fri, Mar 05, 2021 at 04:44:36PM +0100, David Hildenbrand wrote: > On 05.03.21 16:42, Peter Xu wrote: > > On Fri, Mar 05, 2021 at 11:16:33AM +0100, David Hildenbrand wrote: > > > +#define OVERCOMMIT_MEMORY_PATH "/proc/sys/vm/overcommit_memory" > > > +static bool map_noreserve_effective(int fd, bo

Re: [PATCH v2 8/9] util/mmap-alloc: Support RAM_NORESERVE via MAP_NORESERVE

On Fri, Mar 05, 2021 at 11:16:33AM +0100, David Hildenbrand wrote: > +#define OVERCOMMIT_MEMORY_PATH "/proc/sys/vm/overcommit_memory" > +static bool map_noreserve_effective(int fd, bool readonly, bool shared) > +{ [...] > @@ -184,8 +251,7 @@ void *qemu_ram_mmap(int fd, > size_t offset, total

Re: [PATCH v2 8/9] util/mmap-alloc: Support RAM_NORESERVE via MAP_NORESERVE

On 05.03.21 16:42, Peter Xu wrote: On Fri, Mar 05, 2021 at 11:16:33AM +0100, David Hildenbrand wrote: +#define OVERCOMMIT_MEMORY_PATH "/proc/sys/vm/overcommit_memory" +static bool map_noreserve_effective(int fd, bool readonly, bool shared) +{ [...] @@ -184,8 +251,7 @@ void *qemu_ram_mmap(int

[PATCH v2 8/9] util/mmap-alloc: Support RAM_NORESERVE via MAP_NORESERVE

Let's support RAM_NORESERVE via MAP_NORESERVE. At least on Linux, the flag has no effect on shared mappings - except for hugetlbfs. Linux man page: "MAP_NORESERVE: Do not reserve swap space for this mapping. When swap space is reserved, one has the guarantee that it is possible to modify the