Re: [Qemu-devel] [PATCH] block: switch from g_slice allocator to malloc

[Kevin Wolf <kwolf@redhat.com>]

Am 09.10.2015 um 09:49 hat Paolo Bonzini geschrieben:
> On 08/10/2015 11:41, Kevin Wolf wrote:
> > Am 08.10.2015 um 10:54 hat Stefan Hajnoczi geschrieben:
> >> On Thu, Oct 01, 2015 at 01:04:39PM +0200, Paolo Bonzini wrote:
> >>> Simplify memory allocation by sticking with a single API.  GSlice
> >>> is not that fast anyway (tcmalloc/jemalloc are better).
> >>>
> >>> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> >>> ---
> >>>  block/io.c            | 4 ++--
> >>>  block/mirror.c        | 4 ++--
> >>>  block/raw-posix.c     | 8 ++++----
> >>>  block/raw-win32.c     | 4 ++--
> >>>  hw/block/virtio-blk.c | 4 ++--
> >>>  5 files changed, 12 insertions(+), 12 deletions(-)
> >>
> >> Thanks, applied to my block tree:
> >> https://github.com/stefanha/qemu/commits/block
> > 
> > Has someone benchmarked this before applying? Just claiming "wasn't fast
> > anyway" doesn't generally seem sufficient for changes to the I/O path.
> 
> I did it about six months ago.  Sorry for not digging up the results
> when posting:
> 
> baseline: 193 kiops
> tcmalloc: 202 kiops
> tcmalloc + G_SLICE=always-malloc: 210 kiops

Thanks. Do you have numbers for g_malloc + G_SLICE=always-malloc, too?
Because I think that's our new default after this patch. tcmalloc must
still be enabled manually.

Kevin