On 18/06/10 08:04 +0200, Doyu Hiroshi (Nokia-D/Helsinki) wrote: > Hi, > > This is another version of "kmemleak: Fix false positive", which > introduces another alias tree to keep track of all alias address of > each objects, based on the discussion(*1) > > You can also find the previous one(*2), which uses special scan area > for alias addresses with a conversion function. > > Compared with both methods, it seems that the current one takes a bit > longer to scan as below, tested with 512 elementes of (*3). > > "kmemleak: Fix false positive with alias": > # time echo scan > /mnt/kmemleak > real 0m 8.40s > user 0m 0.00s > sys 0m 8.40s > > "kmemleak: Fix false positive with special scan": > # time echo scan > /mnt/kmemleak > real 0m 3.96s > user 0m 0.00s > sys 0m 3.96s > > For our case(*4) to reduce false positives for the 2nd level IOMMU > pagetable allocation, the previous special scan seems to be enough > lightweight, although there might be possiblity to improve alias > one and also I might misunderstand the original proposal of aliasing. > > Any comment would be appreciated. After comparing the two, my Ack would still strongly be behind the first one, the special scan. The additional work over a normal scan is limited strictly to those regions that need it, which is a much more clinical approach to the problem. Your timing data bears that out. Phil > *1: http://lkml.org/lkml/2010/6/2/282 > *2: kmemleak: Fix false positive with special scan > http://lkml.org/lkml/2010/6/1/137 > *3: kmemleak: Add special scan test case > http://lkml.org/lkml/2010/6/1/134 > *4: http://lkml.org/lkml/2010/6/1/136 > > Hiroshi DOYU (1): > kmemleak: Fix false positive with alias > > include/linux/kmemleak.h | 4 + > mm/kmemleak.c | 198 ++++++++++++++++++++++++++++++++++++++-------- > 2 files changed, 168 insertions(+), 34 deletions(-) > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-omap" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
