From: Amit Kapila [mailto:amit.kapil...@gmail.com] > Hmm. It doesn't work even on a command prompt with administrative > privileges. It gives below error: > > waiting for server to start....2017-01-17 11:20:13.780 IST [4788] FATAL: > could not create shared memory segment: error code 1450 > 2017-01-17 11:20:13.780 IST [4788] DETAIL: Failed system call was > CreateFileMap ping(size=148897792, > name=Global/PostgreSQL:E:/WorkSpace/PostgreSQL/master/Data) > . > 2017-01-17 11:20:13.780 IST [4788] LOG: database system is shut down > stopped waiting > pg_ctl: could not start server > Examine the log output. > > > Now, error code 1450 can occur due to insufficient system resources, so > I have tried by increasing the size of shared memory (higher value of > shared_buffers) without your patch and it works. This indicates some > problem with the patch.
Hmm, the large-page requires contiguous memory for each page, so this error could occur on a long-running system where the memory is heavily fragmented. For example, please see the following page and check the memory with RAMMap program referred there. http://blog.dbi-services.com/large-pages-and-memory_target-on-windows/ BTW, is your OS or PostgreSQL 32-bit? > > It seems that Windows removes many privileges, including "Lock Pages > in Memory", when starting the normal command prompt. As its evidence, you > can use the attached priv.c to see what privileges are assigned and and > enabled/disabled. Build it like "cl priv.c" and just run priv.exe on each > command prompt. Those runs show different privileges. > > > > This is bad. > > > Should I need to do something, e.g. explain in the document that the user > should use the command prompt with administrative privileges when he uses > huge_pages? > > > > I think it is better to document in some way if we decide to go-ahead with > the patch. Sure, I added these sentences. + To start the database server on the command prompt as a standalone process, + not as a Windows service, run the command prompt as an administrator or + disable the User Access Control (UAC). When the UAC is enabled, the normal + command prompt revokes the user right Lock Pages in Memory. Regards Takayuki Tsunakawa
win_large_pages_v7.patch
Description: win_large_pages_v7.patch
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