On Thu, 30 Nov 2006 23:51:17 -0800 Paul Jackson <[EMAIL PROTECTED]> wrote:
> A month ago, Christoph replied to pj: > > > > On Sat, 4 Nov 2006, Paul Jackson wrote: > > > > > Do you know of any existing counters that we could use like this? > > > > > > Adding a system wide count of pages allocated or scanned, just for > > > these fullnode hint caches, bothers me. > > > > There are already such counters. PGALLOC_* and PGSCAN_*. See > > include/linux/vmstat.h > > These counters depend on CONFIG_VM_EVENT_COUNTERS. > > The Kconfig comment for CONFIG_VM_EVENT_COUNTERS states: > > VM event counters are only needed to for event counts to be > shown. They have no function for the kernel itself. This > option allows the disabling of the VM event counters. > /proc/vmstat will only show page counts. > > (By the way - note the "needed to for event" phrasing error.) > > The header file, include/linux/vmstat.h, for these counters states: > > /* > * Light weight per cpu counter implementation. > * > * Counters should only be incremented and no critical kernel component > * should rely on the counter values. > > Both these clearly state that I should not use these counters for real > kernel functions. > > If that is so, I should find some other "time base" for the zonelist > caching. > > If that is not so, then these comments need updating. > > Anybody have any idea which is the case? You need to set EMBEDDED to disable VM_EVENT_COUNTERS. Things like procps (vmstat, top, etc) now use /proc/vmstat and would likely break. I don't know how much space it saves, but I doubt if the world would end if we removed CONFIG_VM_EVENT_COUNTERS. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
