> -----Original Message----- > From: linux-fsdevel-owner@xxxxxxxxxxxxxxx > [mailto:linux-fsdevel-owner@xxxxxxxxxxxxxxx] On Behalf Of Waiman Long > Sent: Wednesday, August 16, 2017 1:15 AM > To: Alexander Viro; Jonathan Corbet > Cc: linux-kernel@xxxxxxxxxxxxxxx; linux-doc@xxxxxxxxxxxxxxx; > linux-fsdevel@xxxxxxxxxxxxxxx; Paul E. McKenney; Andrew Morton; Ingo Molnar; > Miklos Szeredi; Matthew Wilcox; Larry Woodman; James Bottomley > Subject: Re: [PATCH v3 0/5] fs/dcache: Limit # of negative dentries > > On 07/28/2017 02:34 PM, Waiman Long wrote: > > v2->v3: > > - Add a faster pruning rate when the free pool is closed to depletion. > > - As suggested by James Bottomley, add an artificial delay waiting > > loop before killing a negative dentry and properly clear the > > DCACHE_KILL_NEGATIVE flag if killing doesn't happen. > > - Add a new patch to track number of negative dentries that are > > forcifully killed. > > > > v1->v2: > > - Move the new nr_negative field to the end of dentry_stat_t structure > > as suggested by Matthew Wilcox. > > - With the help of Miklos Szeredi, fix incorrect locking order in > > dentry_kill() by using lock_parent() instead of locking the parent's > > d_lock directly. > > - Correctly account for positive to negative dentry transitions. > > - Automatic pruning of negative dentries will now ignore the reference > > bit in negative dentries but not the regular shrinking. > > > > A rogue application can potentially create a large number of negative > > dentries in the system consuming most of the memory available. This > > can impact performance of other applications running on the system. > > > > This patchset introduces changes to the dcache subsystem to limit the > > number of negative dentries allowed to be created thus limiting the > > amount of memory that can be consumed by negative dentries. > > > > Patch 1 tracks the number of negative dentries used and disallow the > > creation of more when the limit is reached. > > > > Patch 2 enables /proc/sys/fs/dentry-state to report the number of > > negative dentries in the system. > > > > Patch 3 enables automatic pruning of negative dentries when it is > > close to the limit so that we won't end up killing recently used > > negative dentries. > > > > Patch 4 prevents racing between negative dentry pruning and umount > > operation. > > > > Patch 5 shows the number of forced negative dentry killings in > > /proc/sys/fs/dentry-state. End users can then tune the neg_dentry_pc= > > kernel boot parameter if they want to reduce forced negative dentry > > killings. > > > > Waiman Long (5): > > fs/dcache: Limit numbers of negative dentries > > fs/dcache: Report negative dentry number in dentry-state > > fs/dcache: Enable automatic pruning of negative dentries > > fs/dcache: Protect negative dentry pruning from racing with umount > > fs/dcache: Track count of negative dentries forcibly killed > > > > Documentation/admin-guide/kernel-parameters.txt | 7 + > > fs/dcache.c | 451 > ++++++++++++++++++++++-- > > include/linux/dcache.h | 8 +- > > include/linux/list_lru.h | 1 + > > mm/list_lru.c | 4 +- > > 5 files changed, 435 insertions(+), 36 deletions(-) > > > I haven't received any comment on this v3 patch for over 2 weeks. Is there > anything I can do to make it more ready to be merged? > > Thanks, > Longman Hi Longman, I am a fresher of fsdevel, about 2 weeks before, I have joined this mail list, recently I have met the same problem of negative dentries, in my opinion, the dentries should be remove together with the files or directories, I don't know you have submit this patch, I have another patch about this: http://marc.info/?l=linux-fsdevel&m=150209902215266&w=2 maybe this is a foo idea... regards Kevin ��.n��������+%������w��{.n�����{����* jg��� �����ݢj����G���� ���j:+v���w�m������w�������h�����٥
