Where userland read/write requests, whcih is larger than MAXPHYS, are splitted?

2010-12-10 Thread Lev Serebryakov
Hello, Freebsd-geom. I'm digging thought GEOM/IO code and can not find place, where requests from userland to read more than MAXPHYS bytes, is splitted into several "struct bio"? It seems, that these children request are issued one-by-one, not in parallel, am I right? Wh

Re: Where userland read/write requests, whcih is larger than MAXPHYS, are splitted?

2010-12-10 Thread Alexander Motin
Lev Serebryakov wrote: >I'm digging thought GEOM/IO code and can not find place, where > requests from userland to read more than MAXPHYS bytes, is splitted > into several "struct bio"? > > It seems, that these children request are issued one-by-one, not in > parallel, am

Re: Where userland read/write requests, whcih is larger than MAXPHYS, are splitted?

2010-12-10 Thread Andriy Gapon
on 10/12/2010 15:22 Lev Serebryakov said the following: > Hello, Freebsd-geom. > >I'm digging thought GEOM/IO code and can not find place, where > requests from userland to read more than MAXPHYS bytes, is splitted > into several "struct bio"? Check out g_disk_start(). The split is

Re: Where userland read/write requests, whcih is larger than MAXPHYS, are splitted?

2010-12-10 Thread Andriy Gapon
on 10/12/2010 16:48 Andriy Gapon said the following: > But maybe I misunderstood your question and you talked about a different I/O > layer > or different I/O path. > Oh, probably you talk about physread/physwrite == physio. Indeed, it issues bio-s with max size of si_iosize_max and runs them s

Re: Where userland read/write requests, whcih is larger than MAXPHYS, are splitted?

2010-12-10 Thread Lev Serebryakov
Hello, Alexander. You wrote 10 декабря 2010 г., 17:45:20: >>I'm digging thought GEOM/IO code and can not find place, where >> requests from userland to read more than MAXPHYS bytes, is splitted >> into several "struct bio"? >> It seems, that these children request are issued o

Re: Where userland read/write requests, whcih is larger than MAXPHYS, are splitted?

2010-12-10 Thread Lev Serebryakov
Hello, Andriy. You wrote 10 декабря 2010 г., 18:03:27: > on 10/12/2010 16:48 Andriy Gapon said the following: >> But maybe I misunderstood your question and you talked about a different I/O >> layer >> or different I/O path. > Oh, probably you talk about physread/physwrite == physio. > Indeed, it

Re: Where userland read/write requests, whcih is larger than MAXPHYS, are splitted?

2010-12-10 Thread Andriy Gapon
on 10/12/2010 16:45 Alexander Motin said the following: > by default. Many SCSI drivers still limited by DFLTPHYS - 64K. Including the cases where MAXBSIZE is abused because it historically has the same value. -- Andriy Gapon ___ freebsd-hackers@freeb

Re: Where userland read/write requests, whcih is larger than MAXPHYS, are splitted?

2010-12-10 Thread Alexander Motin
Andriy Gapon wrote: > on 10/12/2010 16:45 Alexander Motin said the following: >> by default. Many SCSI drivers still limited by DFLTPHYS - 64K. > > Including the cases where MAXBSIZE is abused because it historically has the > same > value. DFLTPHYS automatically assumed by CAM for all SIMs not

USENIX ATC '11 Submission Deadline Approaching

2010-12-10 Thread Lionel Garth Jones
We're writing to remind you that the submissions deadline for the 2011 USENIX Annual Technical Conference (USENIX ATC '11) is just over a month away. Please submit your work by 11:59 p.m. EST on Wednesday, January 12, 2011. http://www.usenix.org/atc11/cfpb/ The USENIX ATC '11 Program Committee see