Messages in this thread | | | Date | Tue, 9 May 2006 11:15:56 +0530 | From | Balbir Singh <> | Subject | Re: [Patch 2/8] Sync block I/O and swapin delay collection |
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On Tue, May 09, 2006 at 02:23:15PM +1000, Nick Piggin wrote: > Balbir Singh wrote: > > >On Mon, May 08, 2006 at 02:19:52PM -0700, Andrew Morton wrote: > > > >>Balbir Singh <balbir@in.ibm.com> wrote: > >> > >>>@@ -550,6 +550,12 @@ struct task_delay_info { > >>> * Atomicity of updates to XXX_delay, XXX_count protected by > >>> * single lock above (split into XXX_lock if contention is an issue). > >>> */ > >>>+ > >>>+ struct timespec blkio_start, blkio_end; /* Shared by blkio, swapin */ > >>>+ u64 blkio_delay; /* wait for sync block io completion */ > >>>+ u64 swapin_delay; /* wait for swapin block io completion */ > >>>+ u32 blkio_count; > >>>+ u32 swapin_count; > >>> > >>These fields are a bit mystifying. > >> > >>In what units are blkio_delay and swapin_delay? > >> > >>What is the meaning behind blkio_count and swapin_count? > >> > >>Better comments needed, please. > >> > > > >Will add more detailed comments and send them as updates. > > > > What kinds of usages will this stuff see? Will the CONFIG be usually > turned on, > with some tasks occasionally using the statistics? > > In which case, might it be better to make each delay collector in its > own data > structure { .list; .start; .end; .delay; .count; .private; .name }, and > allocate > them and hang them off the task structure when they're in use? > > Or even put them in their own data structure (a small hash or something). > > OTOH if they're often going to be in use by many tasks, then what you > have might > be the best option. > > Nick > > Send instant messages to your online friends http://au.messenger.yahoo.com
I expect/hope that the CONFIG will be turned on. There is a boot option (called delayacct) to enable/disable the statistics collection. Once turned on and enabled, all tasks will be filling in/using the statistics.
Thanks, Balbir Singh, Linux Technology Center, IBM Software Labs - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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