Re: Improving LWLock wait events - Mailing list pgsql-hackers

From Craig Ringer
Subject Re: Improving LWLock wait events
Date
Msg-id CAGRY4nyNYMHPbturyrWOK47hrLYhq68VdzL2wFVXc6L_bL39mg@mail.gmail.com
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In response to Re: Improving LWLock wait events  (Craig Ringer <craig.ringer@enterprisedb.com>)
List pgsql-hackers
On Wed, 23 Dec 2020 at 15:51, Craig Ringer <craig.ringer@enterprisedb.com> wrote:

I've struggled with this quite a bit myself.


By the way, I sent in a patch to enhance the static tracepoints available for LWLocks. See https://www.postgresql.org/message-id/CAGRY4nxJo+-HCC2i5H93ttSZ4gZO-FSddCwvkb-qAfQ1zdXd1w@mail.gmail.com .

It'd benefit significantly from the sort of changes you mentioned in #4. For most purposes I've been able to just use the raw LWLock* but having a nice neat (tranche,index) value would be ideal.

The trace patch has helped me identify some excessively long LWLock waits in tools I work on. I'll share another of the systemtap scripts I used with it soon.

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