On Sun, Oct 14, 2012 at 6:00 AM, Fujii Masao <masao.fu...@gmail.com> wrote:
> On Sun, Oct 14, 2012 at 3:34 AM, Fujii Masao <masao.fu...@gmail.com> > wrote: > > On Sat, Oct 13, 2012 at 11:34 PM, Satoshi Nagayasu <sn...@uptime.jp> > wrote: > >> Hi, > >> > >> 2012/10/13 23:05, Satoshi Nagayasu wrote: > >>> Hi all, > >>> > >>> I have fixed my previous patch for pg_stat_lwlocks view, and > >>> as Josh commented, it now supports local and global (shared) > >>> statistics in the same system view. > >> > >> Sorry, I found my mistakes. New fixed one is attached to this mail. > > > > Thanks for revising the patch. Here are the comments: > > > > The document needs to be updated. > > > > The patch caused the following compile warnings in my machine. > > > > pgstat.c:1357: warning: no previous prototype for > 'pgstat_report_lwlockstat' > > postgres.c:3922: warning: implicit declaration of function > > 'pgstat_report_lwlockstat' > > pgstatfuncs.c:1854: warning: no previous prototype for > 'pg_stat_reset_lwlocks' > > > > In my test, this patch caused the measurable performance overhead. > > I created the test database by pgbench -s10 and ran pgbench -c8 -j8 -T60 > -S. > > Results are: > > > > [HEAD] > > number of transactions actually processed: 1401369 > > tps = 23351.375811 (including connections establishing) > > tps = 23355.900043 (excluding connections establishing) > > > > [PATCH] > > number of transactions actually processed: 1401369 > > tps = 23351.375811 (including connections establishing) > > tps = 23355.900043 (excluding connections establishing) > > Oops! Obviously I copied and pasted the test result wrongly... > Here is the right result. > > [HEAD] > number of transactions actually processed: 1401369 > tps = 23351.375811 (including connections establishing) > tps = 23355.900043 (excluding connections establishing) > > [PATCH] > number of transactions actually processed: 1092400 > tps = 18179.498013 (including connections establishing) > tps = 18182.450824 (excluding connections establishing) > Performance difference is due to only the mutex lock taken? > > Another comment is; local_calls/waits/time_ms are really required? > I'm not sure how those info would help the performance debugging. > > Regards, > > -- > Fujii Masao > > > -- > Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-hackers > -- Michael Paquier http://michael.otacoo.com