> -----Original Message----- > From: pgsql-hackers-ow...@postgresql.org > [mailto:pgsql-hackers-ow...@postgresql.org] On Behalf Of Robert Haas > Sent: Saturday, March 05, 2016 2:42 AM > To: Kaigai Kouhei(海外 浩平) > Cc: Jim Nasby; pgsql-hackers@postgresql.org; Amit Langote > Subject: Re: [HACKERS] Way to check whether a particular block is on the > shared_buffer? > > On Thu, Mar 3, 2016 at 8:54 PM, Kouhei Kaigai <kai...@ak.jp.nec.com> wrote: > > I found one other, but tiny, problem to implement SSD-to-GPU direct > > data transfer feature under the PostgreSQL storage. > > > > Extension cannot know the raw file descriptor opened by smgr. > > > > I expect an extension issues an ioctl(2) on the special device file > > on behalf of the special kernel driver, to control the P2P DMA. > > This ioctl(2) will pack file descriptor of the DMA source and some > > various information (like base position, range, destination device > > pointer, ...). > > > > However, the raw file descriptor is wrapped in the fd.c, instead of > > the File handler, thus, not visible to extension. oops... > > > > The attached patch provides a way to obtain raw file descriptor (and > > relevant flags) of a particular File virtual file descriptor on > > PostgreSQL. (No need to say, extension has to treat the raw descriptor > > carefully not to give an adverse effect to the storage manager.) > > > > How about this tiny enhancement? > > Why not FileDescriptor(), FileFlags(), FileMode() as separate > functions like FilePathName()? > Here is no deep reason. The attached patch adds three individual functions. Thanks, -- NEC Business Creation Division / PG-Strom Project KaiGai Kohei <kai...@ak.jp.nec.com>
pgsql-v9.6-filegetrawdesc.2.patch
Description: pgsql-v9.6-filegetrawdesc.2.patch
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