Messages in this thread | | | Date | Fri, 20 Apr 2012 11:14:30 -0500 | From | Dave Kleikamp <> | Subject | Re: [RFC PATCH v2 15/21] loop: use aio to perform io on the underlying file |
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On 04/20/2012 10:20 AM, Jeff Moyer wrote: > Dave Kleikamp <dave.kleikamp@oracle.com> writes: > >> On 04/20/2012 09:48 AM, Maxim V. Patlasov wrote: >>> On 03/30/2012 07:43 PM, Dave Kleikamp wrote: >>>> From: Zach Brown<zab@zabbo.net> >>>> >>>> This uses the new kernel aio interface to process loopback IO by >>>> submitting concurrent direct aio. Previously loop's IO was serialized >>>> by synchronous processing in a thread. >>>> >>> >>> The patch ignores REQ_FLUSH bit of bi_rw. Is it simply overlook? >> >> Good question. Since the loop device is sending only direct IO requests, >> it shouldn't be necessary to explicitly flush page cache, but REQ_FLUSH > > REQ_FLUSH isn't about the page cache, it's about flushing the volatile > disk write cache. You need to handle that.
Yeah, and looking again at this code, I need to handle REQ_DISCARD as well.
> > Cheers, > Jeff
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