Re: PHP and Linux performance tweaks

Rasmus Lerdorf wrote: >> I have read that one performance tweak for Linux is to mount the >> filesystem with the "noatime" option (meaning the kernel does not update >> the timestamp whenever files are accessed). >> >> The site relies highly on PHP sessions, and it seems to me that there >> would be trouble with the /tmp/ session files if I configure Linux to >> mount the filesystem with the "noatime" option. As I understand it, the >> PHP session mechanism runs a "stat" operation every time it evaluates >> whether to delete session files. This being the case, I guess the logical > But yes, if you use the standard "files" save_handler on a filesystem that > does not set the atime it will not work. You can see that for yourself in > the ext/session/mod_files.c file in the ps_files_cleanup_dir() function: > > /* check whether its last access was more than maxlifet > ago */ if (VCWD_STAT(buf, &sbuf) == 0 && > (now - sbuf.st_atime) > maxlifetime) { Musings from a naive user who really doesn't know $#!^ about what he's saying :-) Like, if you changed that to sbuf.st_mtime or whatever checks the *MODIFIED* time of the file, it would work more or less okay, no?... I mean, assuming your application actually *CHANGES* session variables with some reasonable degree of frequency... Then old files will get cleaned up when they haven't been *ALTERED* in a long time, rather than accessed, but that should work reasonably well for most cases, I should think... Try this at your own risk... > VCWD_UNLINK(buf); > nrdels++; > } > > Of course, you could set the gc to 0 and do your own garbage collection on > your session files by some other criteria. Not quite sure how you would > determine old and non-active sessions without an atime though. -- Like music? http://l-i-e.com/artists.htm