| Message ID | cover.1586199103.git.zhangweiping@didiglobal.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | Fix potential kernel panic when increase hardware queue | expand |
Weiping Zhang <zhangweiping@didiglobal.com> 于2020年4月7日周二 上午3:36写道： > > Hi, > > This series do some improvement base on V2, and also fix two memleaks. > And V2 import a regression for blktest/block/test/029, this test case > will increase and decrease hardware queue count quickly. > > > Memleak 1: > > __blk_mq_alloc_rq_maps > __blk_mq_alloc_rq_map > > if fail > blk_mq_free_rq_map > > Actually, __blk_mq_alloc_rq_map alloc both map and request, here > also need free request. > > Memleak 2: > When driver decrease hardware queue, set->nr_hw_queues will be changed > firstly in blk_mq_realloc_tag_set_tags or __blk_mq_update_nr_hw_queues, > then blk_mq_realloc_hw_ctxs and blk_mq_map_swqueue, even > blk_mq_free_tag_set have no chance to free these hardware queue resource, > because they iterate hardware queue by > for (i = 0; i < set->nr_hw_queues; i++). > > Patch1~3: rename some function name, no function change. > Patch4: fix first memleak. > Patch5: fix prev_nr_hw_queues issue, need be saved before change. > Patch6: alloc map and request to fix potential kernel panic. > Update patch description: Patch1~3: rename some function name, no function change. Patch4: fix first memleak. Patch5: fix prev_nr_hw_queues issue, need be saved before change. Patch6: add nr_allocated_map_rqs to struct blk_mq_tag_set to record how may rq and maps were allocated for this tag set, and also fix memleak2. Patch7: fix kernel panic when update hardware queue count > cpu count, when use multiple maps. Patch7's commit message has more detail information about this issue. > > Changes since V2: > * rename some functions name and fix memleak when free map and requests > * Not free new allocated map and request, they will be relased when tagset gone > > Changes since V1: > * Add fix for potential kernel panic when increase hardware queue > > Weiping Zhang (7): > block: rename __blk_mq_alloc_rq_map > block: rename __blk_mq_alloc_rq_maps > block: rename blk_mq_alloc_rq_maps > block: free both map and request > block: save previous hardware queue count before udpate > block: refactor __blk_mq_alloc_rq_map_and_requests > block: alloc map and request for new hardware queue > > block/blk-mq.c | 49 ++++++++++++++++++++++++++++++------------ > include/linux/blk-mq.h | 1 + > 2 files changed, 36 insertions(+), 14 deletions(-) > > -- > 2.18.1 >
Hi Jens, Ping On Wed, Apr 8, 2020 at 8:25 PM Weiping Zhang <zwp10758@gmail.com> wrote: > > Weiping Zhang <zhangweiping@didiglobal.com> 于2020年4月7日周二 上午3:36写道： > > > > Hi, > > > > This series do some improvement base on V2, and also fix two memleaks. > > And V2 import a regression for blktest/block/test/029, this test case > > will increase and decrease hardware queue count quickly. > > > > > > Memleak 1: > > > > __blk_mq_alloc_rq_maps > > __blk_mq_alloc_rq_map > > > > if fail > > blk_mq_free_rq_map > > > > Actually, __blk_mq_alloc_rq_map alloc both map and request, here > > also need free request. > > > > Memleak 2: > > When driver decrease hardware queue, set->nr_hw_queues will be changed > > firstly in blk_mq_realloc_tag_set_tags or __blk_mq_update_nr_hw_queues, > > then blk_mq_realloc_hw_ctxs and blk_mq_map_swqueue, even > > blk_mq_free_tag_set have no chance to free these hardware queue resource, > > because they iterate hardware queue by > > for (i = 0; i < set->nr_hw_queues; i++). > > > > Patch1~3: rename some function name, no function change. > > Patch4: fix first memleak. > > Patch5: fix prev_nr_hw_queues issue, need be saved before change. > > Patch6: alloc map and request to fix potential kernel panic. > > > Update patch description: > Patch1~3: rename some function name, no function change. > Patch4: fix first memleak. > Patch5: fix prev_nr_hw_queues issue, need be saved before change. > Patch6: add nr_allocated_map_rqs to struct blk_mq_tag_set to record how > may rq and maps were allocated for this tag set, and also fix memleak2. > > Patch7: fix kernel panic when update hardware queue count > cpu count, > when use multiple maps. Patch7's commit message has more detail information > about this issue. > > > > > Changes since V2: > > * rename some functions name and fix memleak when free map and requests > > * Not free new allocated map and request, they will be relased when tagset gone > > > > Changes since V1: > > * Add fix for potential kernel panic when increase hardware queue > > > > Weiping Zhang (7): > > block: rename __blk_mq_alloc_rq_map > > block: rename __blk_mq_alloc_rq_maps > > block: rename blk_mq_alloc_rq_maps > > block: free both map and request > > block: save previous hardware queue count before udpate > > block: refactor __blk_mq_alloc_rq_map_and_requests > > block: alloc map and request for new hardware queue > > > > block/blk-mq.c | 49 ++++++++++++++++++++++++++++++------------ > > include/linux/blk-mq.h | 1 + > > 2 files changed, 36 insertions(+), 14 deletions(-) > > > > -- > > 2.18.1 > >
On 4/20/20 5:15 AM, Weiping Zhang wrote: > Hi Jens, > > Ping I'd really like for Bart/Ming to weigh in here.