search for: 0.000096

hello *, im running into two major bottlenecks an R script. 1. going through a 40mb file and reading in via readLines() 1 line at a time is almost an order of magnitude slow than the equivalent in python, im wondering if there are alternatives to readLines(), doing more lines at a time helps a bit 2. generating date sequences takes a long time, im basically doing something like

Dear all, When I debugged the execution performance of an application using strace, I found there are some system calls like open and stat64 which run faster on XenLinux than the standard Linux. The following is the output of running "strace -c /bin/sh -c /bin/echo foo" on both systems. An open call runs averagely 109 usec on standard Linux but only 41 usecs on XenLinux. An stat64

So, got some good news: I hear(*) I managed to reproduce the problem with current NUT master and an adapted copy of your posted configs and script :D Experimental debugging now sounds possible. (*) PC under the desk wails with all its cooling fans as soon as I started the client which spawned a daemon and itself had exited: $ UPSNAME=heartbeat at localhost NOTIFYTYPE=ONBATT

So, got some good news: I hear(*) I managed to reproduce the problem with current NUT master and an adapted copy of your posted configs and script :D Experimental debugging now sounds possible. (*) PC under the desk wails with all its cooling fans as soon as I started the client which spawned a daemon and itself had exited: $ UPSNAME=heartbeat at localhost NOTIFYTYPE=ONBATT

After launching the command several times, with debug (posted by new code in a new branch for the investigation) confirming that the same daemon handles operations from the new client instances, its strace now has numerous FDs to report after select() - so I guess it is a problem of detecting an exit of the counterpart. 0.000000 [D2] parse_at: is 'heartbeat at localhost' in AT

After launching the command several times, with debug (posted by new code in a new branch for the investigation) confirming that the same daemon handles operations from the new client instances, its strace now has numerous FDs to report after select() - so I guess it is a problem of detecting an exit of the counterpart. 0.000000 [D2] parse_at: is 'heartbeat at localhost' in AT

Hi, I work for a small company that makes radar systems for research organisations and we use FreeBSD on the PCs for data acquisition and processing. We have recently shifted to FreeBSD6/amd64 and one machine in particular is exhibiting a strange problem. The acquisition process is a Tcl interpreter with a largish chunk of C code which talks to the hardware (via RS485 and a custom PCI card).

Hi, Great work Jim! I?m glad you could reproduce the problem and found a potential culprit. Just for my own interest I restored upsshed from my backups (version 2.7.4-13) and it seems to running ok, so no big runtime changes regarding that with Debian 12. It is not hogging CPU. From the daemon log the heartbeat seems to be working ok. Only difference between the old logs (pre Debian 12 update)

Hi, Great work Jim! I?m glad you could reproduce the problem and found a potential culprit. Just for my own interest I restored upsshed from my backups (version 2.7.4-13) and it seems to running ok, so no big runtime changes regarding that with Debian 12. It is not hogging CPU. From the daemon log the heartbeat seems to be working ok. Only difference between the old logs (pre Debian 12 update)

Hi, Thanks Jim! Here is more system information from the commands you mentioned. Kari root at fricka:~# lsof -p 1716171 lsof: WARNING: can't stat() fuse.gvfsd-fuse file system /run/user/1002/gvfs Output information may be incomplete. COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME upssched 1716171 root cwd DIR 8,2 4096 2 /

Hi, Thanks Jim! Here is more system information from the commands you mentioned. Kari root at fricka:~# lsof -p 1716171 lsof: WARNING: can't stat() fuse.gvfsd-fuse file system /run/user/1002/gvfs Output information may be incomplete. COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME upssched 1716171 root cwd DIR 8,2 4096 2 /

So... determining that FD is to be reaped proved hard. Internet lore suggests fcntl() and poll() on the FD, but it just seems valid to them. The errno is also usually not raised (once I saw a "111: Connection refused" though). So the best dumb idea so far is to bail out if we spent the whole loop (128 attempts) and only got zero-sized read replies and no errors.

So... determining that FD is to be reaped proved hard. Internet lore suggests fcntl() and poll() on the FD, but it just seems valid to them. The errno is also usually not raised (once I saw a "111: Connection refused" though). So the best dumb idea so far is to bail out if we spent the whole loop (128 attempts) and only got zero-sized read replies and no errors.