Messages in this thread |  | | | Date | Tue, 8 Sep 2009 12:13:45 +0800 | | From | Wu Fengguang <> | | Subject | Re: [PATCH] trace bio queueing trial only when it occurs |
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On Tue, Sep 08, 2009 at 12:10:55PM +0800, Minchan Kim wrote: > On Tue, Sep 8, 2009 at 11:02 AM, Li Zefan<lizf@cn.fujitsu.com> wrote: > > Wu Fengguang wrote: > >> Minchan, > >> > >> I tend to agree with the change, but somehow confused by blkparse(1): > >> > >> Q -- queued This notes *intent* to queue i/o at the given location. No real requests exists yet. > >> > >> Li Zefan has been working on blktrace and he can tell more. > >> > > > > I work on ftrace-plugin blktrace and blk TRACE_EVENT, but don't know > > much about the old blktrace history. ;) > > > > I think the manpage says it's called before ->make_request_fn(), so > > "No real requests exist yet". > > > > Actually the trace was called just before make_request at first: > > 2056a782f8e7e65fd4bfd027506b4ce1c5e9ccd4 > > > > And then 2 patches added some checks between them: > > 5ddfe9691c91a244e8d1be597b6428fcefd58103 > > 51fd77bd9f512ab6cc9df0733ba1caaab89eb957 > > > > It seems to me it makes sense to have this patch. > > Thanks for good information. > Yes. It seems above 2 patches seem to break the rule. > Could I add your ACK?
Sure, thanks!
Acked-by: Wu Fengguang <fengguang.wu@intel.com>
> >> Thanks, > >> Fengguang > >> > >> On Tue, Sep 08, 2009 at 08:34:16AM +0800, Minchan Kim wrote: > >>> It got lost in LKML mail storm. > >>> I resend this. > >>> Wu, Could you review this patch, please? > >>> > >>> == CUT_HERE == > >>> > >>> If BIO is discarded or cross over end of device, > >>> BIO queueing trial doesn't occur. > >>> > >>> Let's trace it only when it happens. > >>> > >>> Signed-off-by: Minchan Kim <minchan.kim@gmail.com> > >>> --- > >>> block/blk-core.c | 4 ++-- > >>> 1 files changed, 2 insertions(+), 2 deletions(-) > >>> > >>> diff --git a/block/blk-core.c b/block/blk-core.c > >>> index 5b59592..1a0cfd5 100644 > >>> --- a/block/blk-core.c > >>> +++ b/block/blk-core.c > >>> @@ -1463,8 +1463,6 @@ static inline void __generic_make_request(struct bio *bio) > >>> if (old_sector != -1) > >>> trace_block_remap(q, bio, old_dev, old_sector); > >>> > >>> - trace_block_bio_queue(q, bio); > >>> - > >>> old_sector = bio->bi_sector; > >>> old_dev = bio->bi_bdev->bd_dev; > >>> > >>> @@ -1477,6 +1475,8 @@ static inline void __generic_make_request(struct bio *bio) > >>> goto end_io; > >>> } > >>> > >>> + trace_block_bio_queue(q, bio); > >>> + > >>> ret = q->make_request_fn(q, bio); > >>> } while (ret); > >>> > >>> -- > >>> 1.6.4 > >>> > >>> > >>> > > > > > > -- > Kind regards, > Minchan Kim -- 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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