- 12 Sep, 2013 9 commits
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Michal Hocko authored
The caller of the iterator might know that some nodes or even subtrees should be skipped but there is no way to tell iterators about that so the only choice left is to let iterators to visit each node and do the selection outside of the iterating code. This, however, doesn't scale well with hierarchies with many groups where only few groups are interesting. This patch adds mem_cgroup_iter_cond variant of the iterator with a callback which gets called for every visited node. There are three possible ways how the callback can influence the walk. Either the node is visited, it is skipped but the tree walk continues down the tree or the whole subtree of the current group is skipped. [hughd@google.com: fix memcg-less page reclaim] Signed-off-by:
Michal Hocko <mhocko@suse.cz> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Glauber Costa <glommer@openvz.org> Cc: Greg Thelen <gthelen@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Michel Lespinasse <walken@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Ying Han <yinghan@google.com> Signed-off-by:
Hugh Dickins <hughd@google.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Michal Hocko authored
Soft reclaim has been done only for the global reclaim (both background and direct). Since "memcg: integrate soft reclaim tighter with zone shrinking code" there is no reason for this limitation anymore as the soft limit reclaim doesn't use any special code paths and it is a part of the zone shrinking code which is used by both global and targeted reclaims. From the semantic point of view it is natural to consider soft limit before touching all groups in the hierarchy tree which is touching the hard limit because soft limit tells us where to push back when there is a memory pressure. It is not important whether the pressure comes from the limit or imbalanced zones. This patch simply enables soft reclaim unconditionally in mem_cgroup_should_soft_reclaim so it is enabled for both global and targeted reclaim paths. mem_cgroup_soft_reclaim_eligible needs to learn about the root of the reclaim to know where to stop checking soft limit state of parents up the hierarchy. Say we have A (over soft limit) \ B (below s.l., hit the hard limit) / \ C D (below s.l.) B is the source of the outside memory pressure now for D but we shouldn't soft reclaim it because it is behaving well under B subtree and we can still reclaim from C (pressumably it is over the limit). mem_cgroup_soft_reclaim_eligible should therefore stop climbing up the hierarchy at B (root of the memory pressure). Signed-off-by:
Glauber Costa <glommer@openvz.org> Reviewed-by:
Tejun Heo <tj@kernel.org> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Greg Thelen <gthelen@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Michel Lespinasse <walken@google.com> Cc: Ying Han <yinghan@google.com> Signed-off-by:
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Michal Hocko authored
Now that the soft limit is integrated to the reclaim directly the whole soft-limit tree infrastructure is not needed anymore. Rip it out. Signed-off-by:
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Michal Hocko authored
This patchset is sitting out of tree for quite some time without any objections. I would be really happy if it made it into 3.12. I do not want to push it too hard but I think this work is basically ready and waiting more doesn't help. The basic idea is quite simple. Pull soft reclaim into shrink_zone in the first step and get rid of the previous soft reclaim infrastructure. shrink_zone is done in two passes now. First it tries to do the soft limit reclaim and it falls back to reclaim-all mode if no group is over the limit or no pages have been scanned. The second pass happens at the same priority so the only time we waste is the memcg tree walk which has been updated in the third step to have only negligible overhead. As a bonus we will get rid of a _lot_ of code by this and soft reclaim will not stand out like before when it wasn't integrated into the zone shrinking code and it reclaimed at priority 0 (the testing results show that some workloads suffers from such an aggressive reclaim). The clean up is in a separate patch because I felt it would be easier to review that way. The second step is soft limit reclaim integration into targeted reclaim. It should be rather straight forward. Soft limit has been used only for the global reclaim so far but it makes sense for any kind of pressure coming from up-the-hierarchy, including targeted reclaim. The third step (patches 4-8) addresses the tree walk overhead by enhancing memcg iterators to enable skipping whole subtrees and tracking number of over soft limit children at each level of the hierarchy. This information is updated same way the old soft limit tree was updated (from memcg_check_events) so we shouldn't see an additional overhead. In fact mem_cgroup_update_soft_limit is much simpler than tree manipulation done previously. __shrink_zone uses mem_cgroup_soft_reclaim_eligible as a predicate for mem_cgroup_iter so the decision whether a particular group should be visited is done at the iterator level which allows us to decide to skip the whole subtree as well (if there is no child in excess). This reduces the tree walk overhead considerably. * TEST 1 ======== My primary test case was a parallel kernel build with 2 groups (make is running with -j8 with a distribution .config in a separate cgroup without any hard limit) on a 32 CPU machine booted with 1GB memory and both builds run taskset to Node 0 cpus. I was mostly interested in 2 setups. Default - no soft limit set and - and 0 soft limit set to both groups. The first one should tell us whether the rework regresses the default behavior while the second one should show us improvements in an extreme case where both workloads are always over the soft limit. /usr/bin/time -v has been used to collect the statistics and each configuration had 3 runs after fresh boot without any other load on the system. base is mmotm-2013-07-18-16-40 rework all 8 patches applied on top of base * No-limit User no-limit/base: min: 651.92 max: 672.65 avg: 664.33 std: 8.01 runs: 6 no-limit/rework: min: 657.34 [100.8%] max: 668.39 [99.4%] avg: 663.13 [99.8%] std: 3.61 runs: 6 System no-limit/base: min: 69.33 max: 71.39 avg: 70.32 std: 0.79 runs: 6 no-limit/rework: min: 69.12 [99.7%] max: 71.05 [99.5%] avg: 70.04 [99.6%] std: 0.59 runs: 6 Elapsed no-limit/base: min: 398.27 max: 422.36 avg: 408.85 std: 7.74 runs: 6 no-limit/rework: min: 386.36 [97.0%] max: 438.40 [103.8%] avg: 416.34 [101.8%] std: 18.85 runs: 6 The results are within noise. Elapsed time has a bigger variance but the average looks good. * 0-limit User 0-limit/base: min: 573.76 max: 605.63 avg: 585.73 std: 12.21 runs: 6 0-limit/rework: min: 645.77 [112.6%] max: 666.25 [110.0%] avg: 656.97 [112.2%] std: 7.77 runs: 6 System 0-limit/base: min: 69.57 max: 71.13 avg: 70.29 std: 0.54 runs: 6 0-limit/rework: min: 68.68 [98.7%] max: 71.40 [100.4%] avg: 69.91 [99.5%] std: 0.87 runs: 6 Elapsed 0-limit/base: min: 1306.14 max: 1550.17 avg: 1430.35 std: 90.86 runs: 6 0-limit/rework: min: 404.06 [30.9%] max: 465.94 [30.1%] avg: 434.81 [30.4%] std: 22.68 runs: 6 The improvement is really huge here (even bigger than with my previous testing and I suspect that this highly depends on the storage). Page fault statistics tell us at least part of the story: Minor 0-limit/base: min: 37180461.00 max: 37319986.00 avg: 37247470.00 std: 54772.71 runs: 6 0-limit/rework: min: 36751685.00 [98.8%] max: 36805379.00 [98.6%] avg: 36774506.33 [98.7%] std: 17109.03 runs: 6 Major 0-limit/base: min: 170604.00 max: 221141.00 avg: 196081.83 std: 18217.01 runs: 6 0-limit/rework: min: 2864.00 [1.7%] max: 10029.00 [4.5%] avg: 5627.33 [2.9%] std: 2252.71 runs: 6 Same as with my previous testing Minor faults are more or less within noise but Major fault count is way bellow the base kernel. While this looks as a nice win it is fair to say that 0-limit configuration is quite artificial. So I was playing with 0-no-limit loads as well. * TEST 2 ======== The following results are from 2 groups configuration on a 16GB machine (single NUMA node). - A running stream IO (dd if=/dev/zero of=local.file bs=1024) with 2*TotalMem with 0 soft limit. - B running a mem_eater which consumes TotalMem-1G without any limit. The mem_eater consumes the memory in 100 chunks with 1s nap after each mmap+poppulate so that both loads have chance to fight for the memory. The expected result is that B shouldn't be reclaimed and A shouldn't see a big dropdown in elapsed time. User base: min: 2.68 max: 2.89 avg: 2.76 std: 0.09 runs: 3 rework: min: 3.27 [122.0%] max: 3.74 [129.4%] avg: 3.44 [124.6%] std: 0.21 runs: 3 System base: min: 86.26 max: 88.29 avg: 87.28 std: 0.83 runs: 3 rework: min: 81.05 [94.0%] max: 84.96 [96.2%] avg: 83.14 [95.3%] std: 1.61 runs: 3 Elapsed base: min: 317.28 max: 332.39 avg: 325.84 std: 6.33 runs: 3 rework: min: 281.53 [88.7%] max: 298.16 [89.7%] avg: 290.99 [89.3%] std: 6.98 runs: 3 System time improved slightly as well as Elapsed. My previous testing has shown worse numbers but this again seem to depend on the storage speed. My theory is that the writeback doesn't catch up and prio-0 soft reclaim falls into wait on writeback page too often in the base kernel. The patched kernel doesn't do that because the soft reclaim is done from the kswapd/direct reclaim context. This can be seen on the following graph nicely. The A's group usage_in_bytes regurarly drops really low very often. All 3 runs http://labs.suse.cz/mhocko/soft_limit_rework/stream_io-vs-mem_eater/stream.png resp. a detail of the single run http://labs.suse.cz/mhocko/soft_limit_rework/stream_io-vs-mem_eater/stream-one-run.png mem_eater seems to be doing better as well. It gets to the full allocation size faster as can be seen on the following graph: http://labs.suse.cz/mhocko/soft_limit_rework/stream_io-vs-mem_eater/mem_eater-one-run.png /proc/meminfo collected during the test also shows that rework kernel hasn't swapped that much (well almost not at all): base: max: 123900 K avg: 56388.29 K rework: max: 300 K avg: 128.68 K kswapd and direct reclaim statistics are of no use unfortunatelly because soft reclaim is not accounted properly as the counters are hidden by global_reclaim() checks in the base kernel. * TEST 3 ======== Another test was the same configuration as TEST2 except the stream IO was replaced by a single kbuild (16 parallel jobs bound to Node0 cpus same as in TEST1) and mem_eater allocated TotalMem-200M so kbuild had only 200MB left. Kbuild did better with the rework kernel here as well: User base: min: 860.28 max: 872.86 avg: 868.03 std: 5.54 runs: 3 rework: min: 880.81 [102.4%] max: 887.45 [101.7%] avg: 883.56 [101.8%] std: 2.83 runs: 3 System base: min: 84.35 max: 85.06 avg: 84.79 std: 0.31 runs: 3 rework: min: 85.62 [101.5%] max: 86.09 [101.2%] avg: 85.79 [101.2%] std: 0.21 runs: 3 Elapsed base: min: 135.36 max: 243.30 avg: 182.47 std: 45.12 runs: 3 rework: min: 110.46 [81.6%] max: 116.20 [47.8%] avg: 114.15 [62.6%] std: 2.61 runs: 3 Minor base: min: 36635476.00 max: 36673365.00 avg: 36654812.00 std: 15478.03 runs: 3 rework: min: 36639301.00 [100.0%] max: 36695541.00 [100.1%] avg: 36665511.00 [100.0%] std: 23118.23 runs: 3 Major base: min: 14708.00 max: 53328.00 avg: 31379.00 std: 16202.24 runs: 3 rework: min: 302.00 [2.1%] max: 414.00 [0.8%] avg: 366.33 [1.2%] std: 47.22 runs: 3 Again we can see a significant improvement in Elapsed (it also seems to be more stable), there is a huge dropdown for the Major page faults and much more swapping: base: max: 583736 K avg: 112547.43 K rework: max: 4012 K avg: 124.36 K Graphs from all three runs show the variability of the kbuild quite nicely. It even seems that it took longer after every run with the base kernel which would be quite surprising as the source tree for the build is removed and caches are dropped after each run so the build operates on a freshly extracted sources everytime. http://labs.suse.cz/mhocko/soft_limit_rework/stream_io-vs-mem_eater/kbuild-mem_eater.png My other testing shows that this is just a matter of timing and other runs behave differently the std for Elapsed time is similar ~50. Example of other three runs: http://labs.suse.cz/mhocko/soft_limit_rework/stream_io-vs-mem_eater/kbuild-mem_eater2.png So to wrap this up. The series is still doing good and improves the soft limit. The testing results for bunch of cgroups with both stream IO and kbuild loads can be found in "memcg: track children in soft limit excess to improve soft limit". This patch: Memcg soft reclaim has been traditionally triggered from the global reclaim paths before calling shrink_zone. mem_cgroup_soft_limit_reclaim then picked up a group which exceeds the soft limit the most and reclaimed it with 0 priority to reclaim at least SWAP_CLUSTER_MAX pages. The infrastructure requires per-node-zone trees which hold over-limit groups and keep them up-to-date (via memcg_check_events) which is not cost free. Although this overhead hasn't turned out to be a bottle neck the implementation is suboptimal because mem_cgroup_update_tree has no idea which zones consumed memory over the limit so we could easily end up having a group on a node-zone tree having only few pages from that node-zone. This patch doesn't try to fix node-zone trees management because it seems that integrating soft reclaim into zone shrinking sounds much easier and more appropriate for several reasons. First of all 0 priority reclaim was a crude hack which might lead to big stalls if the group's LRUs are big and hard to reclaim (e.g. a lot of dirty/writeback pages). Soft reclaim should be applicable also to the targeted reclaim which is awkward right now without additional hacks. Last but not least the whole infrastructure eats quite some code. After this patch shrink_zone is done in 2 passes. First it tries to do the soft reclaim if appropriate (only for global reclaim for now to keep compatible with the original state) and fall back to ignoring soft limit if no group is eligible to soft reclaim or nothing has been scanned during the first pass. Only groups which are over their soft limit or any of their parents up the hierarchy is over the limit are considered eligible during the first pass. Soft limit tree which is not necessary anymore will be removed in the follow up patch to make this patch smaller and easier to review. Signed-off-by:
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Li Zefan authored
vfs guarantees the cgroup won't be destroyed, so it's redundant to get a css reference. Signed-off-by:
Li Zefan <lizefan@huawei.com> Acked-by:
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Linus Torvalds authored
This reverts the Linux for Workgroups thing. And no, before somebody asks, we're not doing Linux95. Not for a few years, at least. Sure, the flag added some color to the logo, and could have remained as a testament to my leet gimp skills. But no. And I'll do this early, to avoid the chance of forgetting when I'm doing the actual rc1 release on the road. Signed-off-by: -
Linus Torvalds authored
Merge tag 'ecryptfs-3.12-rc1-crypt-ctx' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs Pull eCryptfs fixes from Tyler Hicks: "Two small fixes to the code that initializes the per-file crypto contexts" * tag 'ecryptfs-3.12-rc1-crypt-ctx' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs: ecryptfs: avoid ctx initialization race ecryptfs: remove check for if an array is NULL
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git://git.linaro.org/people/mszyprowski/linux-dma-mappingLinus Torvalds authored
Pull DMA-mapping fix from Marek Szyprowski: "A build bugfix for the device tree support for reserved memory regions. Due to superfluous include the common code failed to build on ARM64 and MIPS architectures. The patch that caused the build break has lived at linux-next for about two weeks and noone noticed the issue, what convinced me that everything was ok" * 'for-v3.12-fix' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping: drivers: of: fix build break if asm/dma-contiguous.h is missing
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git://git.linaro.org/people/sumitsemwal/linux-dma-bufLinus Torvalds authored
Pull dma-buf updates from Sumit Semwal: "Yet another small one - dma-buf framework now supports size discovery of the buffer via llseek" * tag 'for-3.12' of git://git.linaro.org/people/sumitsemwal/linux-dma-buf: dma-buf: Expose buffer size to userspace (v2) dma-buf: Check return value of anon_inode_getfile
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- 11 Sep, 2013 31 commits
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Linus Torvalds authored
Merge first patch-bomb from Andrew Morton: - Some pidns/fork/exec tweaks - OCFS2 updates - Most of MM - there remain quite a few memcg parts which depend on pending core cgroups changes. Which might have been already merged - I'll check tomorrow... - Various misc stuff all over the place - A few block bits which I never got around to sending to Jens - relatively minor things. - MAINTAINERS maintenance - A small number of lib/ updates - checkpatch updates - epoll - firmware/dmi-scan - Some kprobes work for S390 - drivers/rtc updates - hfsplus feature work - vmcore feature work - rbtree upgrades - AOE updates - pktcdvd cleanups - PPS - memstick - w1 - New "inittmpfs" feature, which does the obvious - More IPC work from Davidlohr. * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (303 commits) lz4: fix compression/decompression signedness mismatch ipc: drop ipc_lock_check ipc, shm: drop shm_lock_check ipc: drop ipc_lock_by_ptr ipc, shm: guard against non-existant vma in shmdt(2) ipc: document general ipc locking scheme ipc,msg: drop msg_unlock ipc: rename ids->rw_mutex ipc,shm: shorten critical region for shmat ipc,shm: cleanup do_shmat pasta ipc,shm: shorten critical region for shmctl ipc,shm: make shmctl_nolock lockless ipc,shm: introduce shmctl_nolock ipc: drop ipcctl_pre_down ipc,shm: shorten critical region in shmctl_down ipc,shm: introduce lockless functions to obtain the ipc object initmpfs: use initramfs if rootfstype= or root= specified initmpfs: make rootfs use tmpfs when CONFIG_TMPFS enabled initmpfs: move rootfs code from fs/ramfs/ to init/ initmpfs: move bdi setup from init_rootfs to init_ramfs ...
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Sergey Senozhatsky authored
LZ4 compression and decompression functions require different in signedness input/output parameters: unsigned char for compression and signed char for decompression. Change decompression API to require "(const) unsigned char *". Signed-off-by:
Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Kyungsik Lee <kyungsik.lee@lge.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Yann Collet <yann.collet.73@gmail.com> Signed-off-by:
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Davidlohr Bueso authored
No remaining users, we now use ipc_obtain_object_check(). Signed-off-by:
Davidlohr Bueso <davidlohr.bueso@hp.com> Cc: Sedat Dilek <sedat.dilek@gmail.com> Cc: Rik van Riel <riel@redhat.com> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by:
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Davidlohr Bueso authored
This function was replaced by a the lockless shm_obtain_object_check(), and no longer has any users. Signed-off-by:
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Davidlohr Bueso authored
After previous cleanups and optimizations, this function is no longer heavily used and we don't have a good reason to keep it. Update the few remaining callers and get rid of it. Signed-off-by:
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Davidlohr Bueso authored
When !CONFIG_MMU there's a chance we can derefence a NULL pointer when the VM area isn't found - check the return value of find_vma(). Also, remove the redundant -EINVAL return: retval is set to the proper return code and *only* changed to 0, when we actually unmap the segments. Signed-off-by:
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Davidlohr Bueso authored
As suggested by Andrew, add a generic initial locking scheme used throughout all sysv ipc mechanisms. Documenting the ids rwsem, how rcu can be enough to do the initial checks and when to actually acquire the kern_ipc_perm.lock spinlock. I found that adding it to util.c was generic enough. Signed-off-by:
Sedat Dilek <sedat.dilek@gmail.com> Cc: Rik van Riel <riel@redhat.com> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by:
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Davidlohr Bueso authored
There is only one user left, drop this function and just call ipc_unlock_object() and rcu_read_unlock(). Signed-off-by:
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Davidlohr Bueso authored
Since in some situations the lock can be shared for readers, we shouldn't be calling it a mutex, rename it to rwsem. Signed-off-by:
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Davidlohr Bueso authored
Similar to other system calls, acquire the kern_ipc_perm lock after doing the initial permission and security checks. [sasha.levin@oracle.com: dont leave do_shmat with rcu lock held] Signed-off-by:
Sasha Levin <sasha.levin@oracle.com> Signed-off-by:
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Davidlohr Bueso authored
Clean up some of the messy do_shmat() spaghetti code, getting rid of out_free and out_put_dentry labels. This makes shortening the critical region of this function in the next patch a little easier to do and read. Signed-off-by:
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Davidlohr Bueso authored
With the *_INFO, *_STAT, IPC_RMID and IPC_SET commands already optimized, deal with the remaining SHM_LOCK and SHM_UNLOCK commands. Take the shm_perm lock after doing the initial auditing and security checks. The rest of the logic remains unchanged. Signed-off-by:
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Davidlohr Bueso authored
While the INFO cmd doesn't take the ipc lock, the STAT commands do acquire it unnecessarily. We can do the permissions and security checks only holding the rcu lock. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by:
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Davidlohr Bueso authored
Similar to semctl and msgctl, when calling msgctl, the *_INFO and *_STAT commands can be performed without acquiring the ipc object. Add a shmctl_nolock() function and move the logic of *_INFO and *_STAT out of msgctl(). Since we are just moving functionality, this change still takes the lock and it will be properly lockless in the next patch. Signed-off-by:
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Davidlohr Bueso authored
Now that sem, msgque and shm, through *_down(), all use the lockless variant of ipcctl_pre_down(), go ahead and delete it. [akpm@linux-foundation.org: fix function name in kerneldoc, cleanups] Signed-off-by:
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Davidlohr Bueso authored
Instead of holding the ipc lock for the entire function, use the ipcctl_pre_down_nolock and only acquire the lock for specific commands: RMID and SET. Signed-off-by:
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Davidlohr Bueso authored
This is the third and final patchset that deals with reducing the amount of contention we impose on the ipc lock (kern_ipc_perm.lock). These changes mostly deal with shared memory, previous work has already been done for semaphores and message queues: http://lkml.org/lkml/2013/3/20/546 (sems) http://lkml.org/lkml/2013/5/15/584 (mqueues) With these patches applied, a custom shm microbenchmark stressing shmctl doing IPC_STAT with 4 threads a million times, reduces the execution time by 50%. A similar run, this time with IPC_SET, reduces the execution time from 3 mins and 35 secs to 27 seconds. Patches 1-8: replaces blindly taking the ipc lock for a smarter combination of rcu and ipc_obtain_object, only acquiring the spinlock when updating. Patch 9: renames the ids rw_mutex to rwsem, which is what it already was. Patch 10: is a trivial mqueue leftover cleanup Patch 11: adds a brief lock scheme description, requested by Andrew. This patch: Add shm_obtain_object() and shm_obtain_object_check(), which will allow us to get the ipc object without acquiring the lock. Just as with other forms of ipc, these functions are basically wrappers around ipc_obtain_object*(). Signed-off-by:
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Rob Landley authored
Command line option rootfstype=ramfs to obtain old initramfs behavior, and use ramfs instead of tmpfs for stub when root= defined (for cosmetic reasons). [akpm@linux-foundation.org: coding-style fixes] Signed-off-by:
Rob Landley <rob@landley.net> Cc: Jeff Layton <jlayton@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Stephen Warren <swarren@nvidia.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jim Cromie <jim.cromie@gmail.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by:
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Rob Landley authored
Conditionally call the appropriate fs_init function and fill_super functions. Add a use once guard to shmem_init() to simply succeed on a second call. (Note that IS_ENABLED() is a compile time constant so dead code elimination removes unused function calls when CONFIG_TMPFS is disabled.) Signed-off-by:
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Rob Landley authored
When the rootfs code was a wrapper around ramfs, having them in the same file made sense. Now that it can wrap another filesystem type, move it in with the init code instead. This also allows a subsequent patch to access rootfstype= command line arg. Signed-off-by:
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Rob Landley authored
Even though ramfs hasn't got a backing device, commit e0bf68dd ("mm: bdi init hooks") added one anyway, and put the initialization in init_rootfs() since that's the first user, leaving it out of init_ramfs() to avoid duplication. But initmpfs uses init_tmpfs() instead, so move the init into the filesystem's init function, add a "once" guard to prevent duplicate initialization, and call the filesystem init from rootfs init. This goes part of the way to allowing ramfs to be built as a module. [akpm@linux-foundation.org; using bit 1 was odd] Signed-off-by:
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Rob Landley authored
Mounting MS_NOUSER prevents --bind mounts from rootfs. Prevent new rootfs mounts with a different mechanism that doesn't affect bind mounts. Signed-off-by:
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Jan Kara authored
With users of radix_tree_preload() run from interrupt (block/blk-ioc.c is one such possible user), the following race can happen: radix_tree_preload() ... radix_tree_insert() radix_tree_node_alloc() if (rtp->nr) { ret = rtp->nodes[rtp->nr - 1]; <interrupt> ... radix_tree_preload() ... radix_tree_insert() radix_tree_node_alloc() if (rtp->nr) { ret = rtp->nodes[rtp->nr - 1]; And we give out one radix tree node twice. That clearly results in radix tree corruption with different results (usually OOPS) depending on which two users of radix tree race. We fix the problem by making radix_tree_node_alloc() always allocate fresh radix tree nodes when in interrupt. Using preloading when in interrupt doesn't make sense since all the allocations have to be atomic anyway and we cannot steal nodes from process-context users because some users rely on radix_tree_insert() succeeding after radix_tree_preload(). in_interrupt() check is somewhat ugly but we cannot simply key off passed gfp_mask as that is acquired from root_gfp_mask() and thus the same for all preload users. Another part of the fix is to avoid node preallocation in radix_tree_preload() when passed gfp_mask doesn't allow waiting. Again, preallocation in such case doesn't make sense and when preallocation would happen in interrupt we could possibly leak some allocated nodes. However, some users of radix_tree_preload() require following radix_tree_insert() to succeed. To avoid unexpected effects for these users, radix_tree_preload() only warns if passed gfp mask doesn't allow waiting and we provide a new function radix_tree_maybe_preload() for those users which get different gfp mask from different call sites and which are prepared to handle radix_tree_insert() failure. Signed-off-by:Jan Kara <jack@suse.cz> Cc: Jens Axboe <jaxboe@fusionio.com> Signed-off-by:
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Jingoo Han authored
The driver core clears the driver data to NULL after device_release or on probe failure. Thus, it is not needed to manually clear the device driver data to NULL. Signed-off-by:
Jingoo Han <jg1.han@samsung.com> Cc: Evgeniy Polyakov <zbr@ioremap.net> Cc: Greg KH <greg@kroah.com> Acked-by:
Shawn Guo <shawn.guo@linaro.org> Signed-off-by:
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Jingoo Han authored
The usage of strict_strtol() is not preferred, because strict_strtol() is obsolete. Thus, kstrtol() should be used. Signed-off-by:
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Maxim Levitsky authored
Based partially on MS standard spec quotes from Alex Dubov. As any code that works with user data this driver isn't recommended to use to write cards that contain valuable data. It tries its best though to avoid data corruption and possible damage to the card. Tested on MS DUO 64 MB card on Ricoh R592 card reader. Signed-off-by:
Maxim Levitsky <maximlevitsky@gmail.com> Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Cc: Jens Axboe <axboe@kernel.dk> Cc: Alex Dubov <oakad@yahoo.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by:
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Jingoo Han authored
The driver core clears the driver data to NULL after device_release or on probe failure. Thus, it is not needed to manually clear the device driver data to NULL. Signed-off-by:
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Jingoo Han authored
The driver core clears the driver data to NULL after device_release or on probe failure. Thus, it is not needed to manually clear the device driver data to NULL. Signed-off-by:
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Joe Perches authored
Fix thinkos where pkt_<level> needs a valid pktcdvd_device * and the pointer is known to be NULL. Signed-off-by:
Joe Perches <joe@perches.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> (go smatch!) Signed-off-by:
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Joe Perches authored
Allow the device name to be emitted with pkt_err when logging the sense data. Signed-off-by:
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Joe Perches authored
Add a new pkt_info macro to prefix the name to the logging output. Signed-off-by:
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