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Re: [Qemu-devel] [RFC PATCH 14/17] block: support FALLOC_FL_PUNCH_HOLE t
Re: [Qemu-devel] [RFC PATCH 14/17] block: support FALLOC_FL_PUNCH_HOLE trimming
Fri, 9 Mar 2012 10:53:31 +0000
On Fri, Mar 9, 2012 at 10:43 AM, Paolo Bonzini <address@hidden> wrote:
> Il 09/03/2012 11:31, Stefan Hajnoczi ha scritto:
>>> > +#ifdef FALLOC_FL_PUNCH_HOLE
>>> > + retval = fallocate(s->fd, FALLOC_FL_PUNCH_HOLE|FALLOC_FL_KEEP_SIZE,
>>> > + sector_num << 9, (int64_t)nb_sectors << 9);
>> I'm concerned about introducing blocking syscalls in coroutine code
>> paths. This needs to be done asynchronously.
> Right; it is no worse than what is already there, except that XFS could
> use paio_ioctl. Alternatives are:
It is worse in the sense that if you make this feature more widely
available then it deserves a production-quality implementation.
> 1) require a new-enough kernel and only use fallocate; return a NULL
> aiocb if !has_discard and convert it to ENOTSUP.
> 2) extract now from my threads branch the work to generalize
> posix-aio-compat into a more flexible threadpool, and move the AIO code
> back to block/raw-posix.c.
3) Add discard to posix-aio-compat.c as an AIO request?
Re: [Qemu-devel] [RFC PATCH 14/17] block: support FALLOC_FL_PUNCH_HOLE trimming, Richard Laager, 2012/03/09
[Qemu-devel] [RFC PATCH 17/17] raw: implement is_allocated, Paolo Bonzini, 2012/03/08
[Qemu-devel] [RFC PATCH 13/17] block: fallback from discard to writes, Paolo Bonzini, 2012/03/08