- 27 10月, 2015 1 次提交
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由 Tejun Heo 提交于
While unifying how blkcg stats are collected, 77ea7338 ("blkcg: move io_service_bytes and io_serviced stats into blkcg_gq") incorrectly used bio->flags instead of bio->rw to tell the IO type. This made IOs to be accounted as the wrong type. Fix it. Signed-off-by: NTejun Heo <tj@kernel.org> Fixes: 77ea7338 ("blkcg: move io_service_bytes and io_serviced stats into blkcg_gq") Reviewed-by: NJeff Moyer <jmoyer@redhat.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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- 19 8月, 2015 20 次提交
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由 Tejun Heo 提交于
cgroup is trying to make interface consistent across different controllers. For weight based resource control, the knob should have the range [1, 10000] and default to 100. This patch updates cfq-iosched so that the weight range conforms. The internal calculations have enough range and the widening of the weight range shouldn't cause any problem. * blkcg_policy->cpd_bind_fn() is added. If present, this is invoked when blkcg is attached to a hierarchy. * cfq_cpd_init() is updated to use the new default value on the unified hierarchy. * cfq_cpd_bind() callback is implemented to clear per-blkg configs and apply the default config matching the hierarchy type. * cfqd->root_group->[leaf_]weight initialization in cfq_init_queue() is moved into !CONFIG_CFQ_GROUP_IOSCHED block. cfq_cpd_bind() is now responsible for initializing the initial weights when blkcg is enabled. Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Arianna Avanzini <avanzini.arianna@gmail.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Tejun Heo 提交于
blkcg interface grew to be the biggest of all controllers and unfortunately most inconsistent too. The interface files are inconsistent with a number of cloes duplicates. Some files have recursive variants while others don't. There's distinction between normal and leaf weights which isn't intuitive and there are a lot of stat knobs which don't make much sense outside of debugging and expose too much implementation details to userland. In the unified hierarchy, everything is always hierarchical and internal nodes can't have tasks rendering the two structural issues twisting the current interface. The interface has to be updated in a significant anyway and this is a good chance to revamp it as a whole. This patch implements blkcg interface for the unified hierarchy. * (from a previous patch) blkcg is identified by "io" instead of "blkio" on the unified hierarchy. Given that the whole interface is updated anyway, the rename shouldn't carry noticeable conversion overhead. * The original interface consisted of 27 files is replaced with the following three files. blkio.stat : per-blkcg stats blkio.weight : per-cgroup and per-cgroup-queue weight settings blkio.max : per-cgroup-queue bps and iops max limits Documentation/cgroups/unified-hierarchy.txt updated accordingly. v2: blkcg_policy->dfl_cftypes wasn't removed on blkcg_policy_unregister() corrupting the cftypes list. Fixed. Signed-off-by: NTejun Heo <tj@kernel.org> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Tejun Heo 提交于
* Export blkg_dev_name() * Drop unnecessary @cft from __cfq_set_weight(). Signed-off-by: NTejun Heo <tj@kernel.org> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Tejun Heo 提交于
Currently, blkg_conf_prep() expects input to be of the following form MAJ:MIN NUM and reads the NUM part into blkg_conf_ctx->v. This is quite restrictive and gets in the way in implementing blkcg interface for the unified hierarchy. This patch updates blkg_conf_prep() so that it expects MAJ:MIN BODY_STR where BODY_STR is an arbitrary string. blkg_conf_ctx->v is replaced with ->body which is a char pointer pointing to the start of BODY_STR. Parsing of the body is moved to blkg_conf_prep()'s callers. To allow using, for example, strsep() on blkg_conf_ctx->val, it is a non-const pointer and to accommodate that const is dropped from @input too. This doesn't cause any behavior changes. Signed-off-by: NTejun Heo <tj@kernel.org> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Tejun Heo 提交于
blkcg is about to grow interface for the unified hierarchy. Add legacy to existing cftypes. * blkcg_policy->cftypes -> blkcg_policy->legacy_cftypes * blk-cgroup.c:blkcg_files -> blkcg_legacy_files * cfq-iosched.c:cfq_blkcg_files -> cfq_blkcg_legacy_files * blk-throttle.c:throtl_files -> throtl_legacy_files Pure renames. No functional change. Signed-off-by: NTejun Heo <tj@kernel.org> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Tejun Heo 提交于
blkio interface has become messy over time and is currently the largest. In addition to the inconsistent naming scheme, it has multiple stat files which report more or less the same thing, a number of debug stat files which expose internal details which shouldn't have been part of the public interface in the first place, recursive and non-recursive stats and leaf and non-leaf knobs. Both recursive vs. non-recursive and leaf vs. non-leaf distinctions don't make any sense on the unified hierarchy as only leaf cgroups can contain processes. cgroups is going through a major interface revision with the unified hierarchy involving significant fundamental usage changes and given that a significant portion of the interface doesn't make sense anymore, it's a good time to reorganize the interface. As the first step, this patch renames the external visible subsystem name from "blkio" to "io". This is more concise, matches the other two major subsystem names, "cpu" and "memory", and better suited as blkcg will be involved in anything writeback related too whether an actual block device is involved or not. As the subsystem legacy_name is set to "blkio", the only userland visible change outside the unified hierarchy is that blkcg is reported as "io" instead of "blkio" in the subsystem initialized message during boot. On the unified hierarchy, blkcg now appears as "io". Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Li Zefan <lizefan@huawei.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: cgroups@vger.kernel.org Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Tejun Heo 提交于
Currently, both cfq-iosched and blk-throttle keep track of io_service_bytes and io_serviced stats. While keeping track of them separately may be useful during development, it doesn't make much sense otherwise. Also, blk-throttle was counting bio's as IOs while cfq-iosched request's, which is more confusing than informative. This patch adds ->stat_bytes and ->stat_ios to blkg (blkcg_gq), removes the counterparts from cfq-iosched and blk-throttle and let them print from the common blkg counters. The common counters are incremented during bio issue in blkcg_bio_issue_check(). The outputs are still filtered by whether the policy has blkg_policy_data on a given blkg, so cfq's output won't show up if it has never been used for a given blkg. The only times when the outputs would differ significantly are when policies are attached on the fly or elevators are switched back and forth. Those are quite exceptional operations and I don't think they warrant keeping separate counters. v3: Update blkio-controller.txt accordingly. v2: Account IOs during bio issues instead of request completions so that bio-based drivers can be handled the same way. Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Tejun Heo 提交于
Currently, blkg_[rw]stat_recursive_sum() assume that the target counter is located in pd (blkg_policy_data); however, some counters are planned to be moved to blkg (blkcg_gq). This patch updates blkg_[rw]stat_recursive_sum() to take blkg and blkg_policy pointers instead of pd. If policy is NULL, it indexes into blkg. If non-NULL, into the blkg's pd of the policy. The existing usages are updated to maintain the current behaviors. Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Tejun Heo 提交于
blkcg_[rw]stat are used as stat counters for blkcg policies. It isn't per-cpu by itself and blk-throttle makes it per-cpu by wrapping around it. This patch makes blkcg_[rw]stat per-cpu and drop the ad-hoc per-cpu wrapping in blk-throttle. * blkg_[rw]stat->cnt is replaced with cpu_cnt which is struct percpu_counter. This makes syncp unnecessary as remote accesses are handled by percpu_counter itself. * blkg_[rw]stat_init() can now fail due to percpu allocation failure and thus are updated to return int. * percpu_counters need explicit freeing. blkg_[rw]stat_exit() added. * As blkg_rwstat->cpu_cnt[] can't be read directly anymore, reading and summing results are stored in ->aux_cnt[] instead. * Custom per-cpu stat implementation in blk-throttle is removed. This makes all blkcg stat counters per-cpu without complicating policy implmentations. Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Tejun Heo 提交于
cgroup stats are local to each cgroup and doesn't propagate to ancestors by default. When recursive stats are necessary, the sum is calculated over all the descendants. This initially was for backward compatibility to support both group-local and recursive stats but this mode of operation makes general sense as stat update is much hotter thafn reporting those stats. This however ends up losing recursive stats when a child is removed. To work around this, cfq-iosched adds its stats to its parent cfq_group->dead_stats which is summed up together when calculating recursive stats. It's planned that the core stats will be moved to blkcg_gq, so we want to move the mechanism for keeping track of the stats of dead children from cfq to blkcg core. This patch adds blkg_[rw]stat->aux_cnt which are atomic64_t's keeping track of auxiliary counts which are excluded when reading local counts but included for recursive. blkg_[rw]stat_merge() which were used by cfq to implement dead_stats are replaced by blkg_[rw]stat_add_aux(), and cfq now forwards stats of a dead cgroup to the aux counts of parent->stats instead of separate ->dead_stats. This will also help making blkg_[rw]stats per-cpu. Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Tejun Heo 提交于
blkg (blkcg_gq) currently is created by blkcg policies invoking blkg_lookup_create() which ends up repeating about the same code in different policies. Theoretically, this can avoid the overhead of looking and/or creating blkg's if blkcg is enabled but no policy is in use; however, the cost of blkg lookup / creation is very low especially if only the root blkcg is in use which is highly likely if no blkcg policy is in active use - it boils down to a single very predictable conditional and surrounding RCU protection. This patch consolidates blkg creation to a new function blkcg_bio_issue_check() which is called during bio issue from generic_make_request_checks(). blkcg_bio_issue_check() is now the only function which tries to create missing blkg's. The subsequent policy and request_list operations just perform blkg_lookup() and if missing falls back to the root. * blk_get_rl() no longer tries to create blkg. It uses blkg_lookup() instead of blkg_lookup_create(). * blk_throtl_bio() is now called from blkcg_bio_issue_check() with rcu read locked and blkg already looked up. Both throtl_lookup_tg() and throtl_lookup_create_tg() are dropped. * cfq is similarly updated. cfq_lookup_create_cfqg() is replaced with cfq_lookup_cfqg()which uses blkg_lookup(). This consolidates blkg handling and avoids unnecessary blkg creation retries under memory pressure. In addition, this provides a common bio entry point into blkcg where things like common accounting can be performed. v2: Build fixes for !CONFIG_CFQ_GROUP_IOSCHED and !CONFIG_BLK_DEV_THROTTLING. Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Arianna Avanzini <avanzini.arianna@gmail.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Tejun Heo 提交于
Currently, both throttle and cfq policies implement their own root blkg (blkcg_gq) lookup fast path. This patch moves root blkg optimization from throtl_lookup_tg() to __blkg_lookup(). cfq-iosched currently doesn't use blkg_lookup() but will be converted and drop the optimization too. Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Arianna Avanzini <avanzini.arianna@gmail.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Tejun Heo 提交于
blkg_lookup() checks whether the target queue is bypassing and, if not, calls __blkg_lookup() which first checks the lookup hint and then performs radix tree walk. The operations upto hint checking are trivial and there are many users of this function. This patch inlines blkg_lookup() and the fast path part of __blkg_lookup(). The radix tree lookup and hint update are now in blkg_lookup_slowpath(). This will help consolidating blkg handling by easing moving root blkcg short-circuit to inlined lookup fast path. Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Arianna Avanzini <avanzini.arianna@gmail.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Tejun Heo 提交于
Each active policy has a cpd (blkcg_policy_data) on each blkcg. The cpd's were allocated by blkcg core and each policy could request to allocate extra space at the end by setting blkcg_policy->cpd_size larger than the size of cpd. This is a bit unusual but blkg (blkcg_gq) policy data used to be handled this way too so it made sense to be consistent; however, blkg policy data switched to alloc/free callbacks. This patch makes similar changes to cpd handling. blkcg_policy->cpd_alloc/free_fn() are added to replace ->cpd_size. As cpd allocation is now done from policy side, it can simply allocate a larger area which embeds cpd at the beginning. As ->cpd_alloc_fn() may be able to perform all necessary initializations, this patch makes ->cpd_init_fn() optional. Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Arianna Avanzini <avanzini.arianna@gmail.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Tejun Heo 提交于
* Rename blkcg->pd[] to blkcg->cpd[] so that cpd is consistently used for blkcg_policy_data. * Make blkcg_policy->cpd_init_fn() take blkcg_policy_data instead of blkcg. This makes it consistent with blkg_policy_data methods and to-be-added cpd alloc/free methods. * blkcg_policy_data->blkcg and cpd_to_blkcg() added so that cpd_init_fn() can determine the associated blkcg from blkcg_policy_data. v2: blkcg_policy_data->blkcg initializations were missing. Added. Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Arianna Avanzini <avanzini.arianna@gmail.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Tejun Heo 提交于
The newly added ->pd_alloc_fn() and ->pd_free_fn() deal with pd (blkg_policy_data) while the older ones use blkg (blkcg_gq). As using blkg doesn't make sense for ->pd_alloc_fn() and after allocation pd can always be mapped to blkg and given that these are policy-specific methods, it makes sense to converge on pd. This patch makes all methods deal with pd instead of blkg. Most conversions are trivial. In blk-cgroup.c, a couple method invocation sites now test whether pd exists instead of policy state for consistency. This shouldn't cause any behavioral differences. Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Tejun Heo 提交于
With the recent addition of alloc and free methods, things became messier. This patch reorganizes them according to the followings. * ->pd_alloc_fn() Responsible for allocation and static initializations - the ones which can be done independent of where the pd might be attached. * ->pd_init_fn() Initializations which require the knowledge of where the pd is attached. * ->pd_free_fn() The counter part of pd_alloc_fn(). Static de-init and freeing. This leaves ->pd_exit_fn() without any users. Removed. While at it, collapse an one liner function throtl_pd_exit(), which has only one user, into its user. Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Tejun Heo 提交于
A blkg (blkcg_gq) represents the relationship between a cgroup and request_queue. Each active policy has a pd (blkg_policy_data) on each blkg. The pd's were allocated by blkcg core and each policy could request to allocate extra space at the end by setting blkcg_policy->pd_size larger than the size of pd. This is a bit unusual but was done this way mostly to simplify error handling and all the existing use cases could be handled this way; however, this is becoming too restrictive now that percpu memory can be allocated without blocking. This introduces two new mandatory blkcg_policy methods - pd_alloc_fn() and pd_free_fn() - which are used to allocate and release pd for a given policy. As pd allocation is now done from policy side, it can simply allocate a larger area which embeds pd at the beginning. This change makes ->pd_size pointless. Removed. Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Tejun Heo 提交于
When a policy gets activated, it needs to allocate and install its policy data on all existing blkg's (blkcg_gq's). Because blkg iteration is protected by a spinlock, it currently counts the total number of blkg's in the system, allocates the matching number of policy data on a list and installs them during a single iteration. This can be simplified by using speculative GFP_NOWAIT allocations while iterating and falling back to a preallocated policy data on failure. If the preallocated one has already been consumed, it releases the lock, preallocate with GFP_KERNEL and then restarts the iteration. This can be a bit more expensive than before but policy activation is a very cold path and shouldn't matter. Signed-off-by: NTejun Heo <tj@kernel.org> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Tejun Heo 提交于
Since ec13b1d6 ("blkcg: always create the blkcg_gq for the root blkcg"), a request_list always has its blkg associated. Drop unnecessary rl->blkg NULL test from blk_put_rl(). Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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- 14 8月, 2015 1 次提交
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由 Viresh Kumar 提交于
IS_ERR(_OR_NULL) already contain an 'unlikely' compiler flag and there is no need to do that again from its callers. Drop it. Acked-by: NTejun Heo <tj@kernel.org> Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org> Signed-off-by: NJens Axboe <axboe@fb.com>
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- 10 7月, 2015 2 次提交
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由 Tejun Heo 提交于
e48453c3 ("block, cgroup: implement policy-specific per-blkcg data") updated per-blkcg policy data to be dynamically allocated. When a policy is registered, its policy data aren't created. Instead, when the policy is activated on a queue, the policy data are allocated if there are blkg's (blkcg_gq's) which are attached to a given blkcg. This is buggy. Consider the following scenario. 1. A blkcg is created. No blkg's attached yet. 2. The policy is registered. No policy data is allocated. 3. The policy is activated on a queue. As the above blkcg doesn't have any blkg's, it won't allocate the matching blkcg_policy_data. 4. An IO is issued from the blkcg and blkg is created and the blkcg still doesn't have the matching policy data allocated. With cfq-iosched, this leads to an oops. It also doesn't free policy data on policy unregistration assuming that freeing of all policy data on blkcg destruction should take care of it; however, this also is incorrect. 1. A blkcg has policy data. 2. The policy gets unregistered but the policy data remains. 3. Another policy gets registered on the same slot. 4. Later, the new policy tries to allocate policy data on the previous blkcg but the slot is already occupied and gets skipped. The policy ends up operating on the policy data of the previous policy. There's no reason to manage blkcg_policy_data lazily. The reason we do lazy allocation of blkg's is that the number of all possible blkg's is the product of cgroups and block devices which can reach a surprising level. blkcg_policy_data is contrained by the number of cgroups and shouldn't be a problem. This patch makes blkcg_policy_data to be allocated for all existing blkcg's on policy registration and freed on unregistration and removes blkcg_policy_data handling from policy [de]activation paths. This makes that blkcg_policy_data are created and removed with the policy they belong to and fixes the above described problems. Signed-off-by: NTejun Heo <tj@kernel.org> Fixes: e48453c3 ("block, cgroup: implement policy-specific per-blkcg data") Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Arianna Avanzini <avanzini.arianna@gmail.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Tejun Heo 提交于
Add all_blkcgs list goes through blkcg->all_blkcgs_node and is protected by blkcg_pol_mutex. This will be used to fix blkcg_policy_data allocation bug. Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Arianna Avanzini <avanzini.arianna@gmail.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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- 02 6月, 2015 6 次提交
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由 Tejun Heo 提交于
A blkg (blkcg_gq) can be congested and decongested independently from other blkgs on the same request_queue. Accordingly, for cgroup writeback support, the congestion status at bdi (backing_dev_info) should be split and updated separately from matching blkg's. This patch prepares by adding blkg->wb_congested and associating a blkg with its matching per-blkcg bdi_writeback_congested on creation. v2: Updated to associate bdi_writeback_congested instead of bdi_writeback. Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jan Kara <jack@suse.cz> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Tejun Heo 提交于
For the planned cgroup writeback support, on each bdi (backing_dev_info), each memcg will be served by a separate wb (bdi_writeback). This patch updates bdi so that a bdi can host multiple wbs (bdi_writebacks). On the default hierarchy, blkcg implicitly enables memcg. This allows using memcg's page ownership for attributing writeback IOs, and every memcg - blkcg combination can be served by its own wb by assigning a dedicated wb to each memcg. This means that there may be multiple wb's of a bdi mapped to the same blkcg. As congested state is per blkcg - bdi combination, those wb's should share the same congested state. This is achieved by tracking congested state via bdi_writeback_congested structs which are keyed by blkcg. bdi->wb remains unchanged and will keep serving the root cgroup. cgwb's (cgroup wb's) for non-root cgroups are created on-demand or looked up while dirtying an inode according to the memcg of the page being dirtied or current task. Each cgwb is indexed on bdi->cgwb_tree by its memcg id. Once an inode is associated with its wb, it can be retrieved using inode_to_wb(). Currently, none of the filesystems has FS_CGROUP_WRITEBACK and all pages will keep being associated with bdi->wb. v3: inode_attach_wb() in account_page_dirtied() moved inside mapping_cap_account_dirty() block where it's known to be !NULL. Also, an unnecessary NULL check before kfree() removed. Both detected by the kbuild bot. v2: Updated so that wb association is per inode and wb is per memcg rather than blkcg. Signed-off-by: NTejun Heo <tj@kernel.org> Cc: kbuild test robot <fengguang.wu@intel.com> Cc: Dan Carpenter <dan.carpenter@oracle.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jan Kara <jack@suse.cz> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Tejun Heo 提交于
Implement a wrapper around task_get_css() to acquire the blkcg css for a given task. The wrapper is necessary for cgroup writeback support as there will be places outside blkcg proper trying to acquire blkcg_css and blkio_cgrp_id will be undefined when !CONFIG_BLK_CGROUP. Signed-off-by: NTejun Heo <tj@kernel.org> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Tejun Heo 提交于
Add global constant blkcg_root_css which points to &blkcg_root.css. This will be used by cgroup writeback support. If blkcg is disabled, it's defined as ERR_PTR(-EINVAL). v2: The declarations moved to include/linux/blk-cgroup.h as suggested by Vivek. Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Tejun Heo 提交于
The header file will be used more widely with the pending cgroup writeback support and the current set of dummy declarations aren't enough to handle different config combinations. Update as follows. * Drop the struct cgroup declaration. None of the dummy defs need it. * Define blkcg as an empty struct instead of just declaring it. * Wrap dummy function defs in CONFIG_BLOCK. Some functions use block data types and none of them are to be used w/o block enabled. Signed-off-by: NTejun Heo <tj@kernel.org> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Tejun Heo 提交于
cgroup aware writeback support will require exposing some of blkcg details. In preprataion, move block/blk-cgroup.h to include/linux/blk-cgroup.h. This patch is pure file move. Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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- 08 9月, 2014 1 次提交
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由 Tejun Heo 提交于
blkcg->id is a unique id given to each blkcg; however, the cgroup_subsys_state which each blkcg embeds already has ->serial_nr which can be used for the same purpose. Drop blkcg->id and replace its uses with blkcg->css.serial_nr. Rename cfq_cgroup->blkcg_id to ->blkcg_serial_nr and @id in check_blkcg_changed() to @serial_nr for consistency. Signed-off-by: NTejun Heo <tj@kernel.org> Acked-by: NVivek Goyal <vgoyal@redhat.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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- 23 6月, 2014 2 次提交
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由 Jens Axboe 提交于
This reverts commit a2d445d4. The original commit is buggy, we do use the registration functions at runtime for modular builds.
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由 Tejun Heo 提交于
Hello, So, this patch should do. Joe, Vivek, can one of you guys please verify that the oops goes away with this patch? Jens, the original thread can be read at http://thread.gmane.org/gmane.linux.kernel/1720729 The fix converts blkg->refcnt from int to atomic_t. It does some overhead but it should be minute compared to everything else which is going on and the involved cacheline bouncing, so I think it's highly unlikely to cause any noticeable difference. Also, the refcnt in question should be converted to a perpcu_ref for blk-mq anyway, so the atomic_t is likely to go away pretty soon anyway. Thanks. ------- 8< ------- __blkg_release_rcu() may be invoked after the associated request_queue is released with a RCU grace period inbetween. As such, the function and callbacks invoked from it must not dereference the associated request_queue. This is clearly indicated in the comment above the function. Unfortunately, while trying to fix a different issue, 2a4fd070 ("blkcg: move bulk of blkcg_gq release operations to the RCU callback") ignored this and added [un]locking of @blkg->q->queue_lock to __blkg_release_rcu(). This of course can cause oops as the request_queue may be long gone by the time this code gets executed. general protection fault: 0000 [#1] SMP CPU: 21 PID: 30 Comm: rcuos/21 Not tainted 3.15.0 #1 Hardware name: Stratus ftServer 6400/G7LAZ, BIOS BIOS Version 6.3:57 12/25/2013 task: ffff880854021de0 ti: ffff88085403c000 task.ti: ffff88085403c000 RIP: 0010:[<ffffffff8162e9e5>] [<ffffffff8162e9e5>] _raw_spin_lock_irq+0x15/0x60 RSP: 0018:ffff88085403fdf0 EFLAGS: 00010086 RAX: 0000000000020000 RBX: 0000000000000010 RCX: 0000000000000000 RDX: 000060ef80008248 RSI: 0000000000000286 RDI: 6b6b6b6b6b6b6b6b RBP: ffff88085403fdf0 R08: 0000000000000286 R09: 0000000000009f39 R10: 0000000000020001 R11: 0000000000020001 R12: ffff88103c17a130 R13: ffff88103c17a080 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88107fca0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000006e5ab8 CR3: 000000000193d000 CR4: 00000000000407e0 Stack: ffff88085403fe18 ffffffff812cbfc2 ffff88103c17a130 0000000000000000 ffff88103c17a130 ffff88085403fec0 ffffffff810d1d28 ffff880854021de0 ffff880854021de0 ffff88107fcaec58 ffff88085403fe80 ffff88107fcaec30 Call Trace: [<ffffffff812cbfc2>] __blkg_release_rcu+0x72/0x150 [<ffffffff810d1d28>] rcu_nocb_kthread+0x1e8/0x300 [<ffffffff81091d81>] kthread+0xe1/0x100 [<ffffffff8163813c>] ret_from_fork+0x7c/0xb0 Code: ff 47 04 48 8b 7d 08 be 00 02 00 00 e8 55 48 a4 ff 5d c3 0f 1f 00 66 66 66 66 90 55 48 89 e5 +fa 66 66 90 66 66 90 b8 00 00 02 00 <f0> 0f c1 07 89 c2 c1 ea 10 66 39 c2 75 02 5d c3 83 e2 fe 0f +b7 RIP [<ffffffff8162e9e5>] _raw_spin_lock_irq+0x15/0x60 RSP <ffff88085403fdf0> The request_queue locking was added because blkcg_gq->refcnt is an int protected with the queue lock and __blkg_release_rcu() needs to put the parent. Let's fix it by making blkcg_gq->refcnt an atomic_t and dropping queue locking in the function. Given the general heavy weight of the current request_queue and blkcg operations, this is unlikely to cause any noticeable overhead. Moreover, blkcg_gq->refcnt is likely to be converted to percpu_ref in the near future, so whatever (most likely negligible) overhead it may add is temporary. Signed-off-by: NTejun Heo <tj@kernel.org> Reported-by: NJoe Lawrence <joe.lawrence@stratus.com> Acked-by: NVivek Goyal <vgoyal@redhat.com> Link: http://lkml.kernel.org/g/alpine.DEB.2.02.1406081816540.17948@jlaw-desktop.mno.stratus.com Cc: stable@vger.kernel.org Signed-off-by: NJens Axboe <axboe@fb.com>
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- 11 6月, 2014 1 次提交
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由 Fabian Frederick 提交于
blkcg_policy_register is only called by __init functions: __init cfq_init __init throtl_init Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: NFabian Frederick <fabf@skynet.be> Signed-off-by: NJens Axboe <axboe@fb.com>
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- 17 5月, 2014 1 次提交
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由 Tejun Heo 提交于
cgroup in general is moving towards using cgroup_subsys_state as the fundamental structural component and css_parent() was introduced to convert from using cgroup->parent to css->parent. It was quite some time ago and we're moving forward with making css more prominent. This patch drops the trivial wrapper css_parent() and let the users dereference css->parent. While at it, explicitly mark fields of css which are public and immutable. v2: New usage from device_cgroup.c converted. Signed-off-by: NTejun Heo <tj@kernel.org> Acked-by: NMichal Hocko <mhocko@suse.cz> Acked-by: NNeil Horman <nhorman@tuxdriver.com> Acked-by: N"David S. Miller" <davem@davemloft.net> Acked-by: NLi Zefan <lizefan@huawei.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Johannes Weiner <hannes@cmpxchg.org>
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- 15 3月, 2014 1 次提交
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由 Eric W. Biederman 提交于
Replace the bh safe variant with the hard irq safe variant. We need a hard irq safe variant to deal with netpoll transmitting packets from hard irq context, and we need it in most if not all of the places using the bh safe variant. Except on 32bit uni-processor the code is exactly the same so don't bother with a bh variant, just have a hard irq safe variant that everyone can use. Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 12 2月, 2014 1 次提交
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由 Tejun Heo 提交于
cgroup->name handling became quite complicated over time involving dedicated struct cgroup_name for RCU protection. Now that cgroup is on kernfs, we can drop all of it and simply use kernfs_name/path() and friends. Replace cgroup->name and all related code with kernfs name/path constructs. * Reimplement cgroup_name() and cgroup_path() as thin wrappers on top of kernfs counterparts, which involves semantic changes. pr_cont_cgroup_name() and pr_cont_cgroup_path() added. * cgroup->name handling dropped from cgroup_rename(). * All users of cgroup_name/path() updated to the new semantics. Users which were formatting the string just to printk them are converted to use pr_cont_cgroup_name/path() instead, which simplifies things quite a bit. As cgroup_name() no longer requires RCU read lock around it, RCU lockings which were protecting only cgroup_name() are removed. v2: Comment above oom_info_lock updated as suggested by Michal. v3: dummy_top doesn't have a kn associated and pr_cont_cgroup_name/path() ended up calling the matching kernfs functions with NULL kn leading to oops. Test for NULL kn and print "/" if so. This issue was reported by Fengguang Wu. v4: Rebased on top of 0ab02ca8 ("cgroup: protect modifications to cgroup_idr with cgroup_mutex"). Signed-off-by: NTejun Heo <tj@kernel.org> Acked-by: NPeter Zijlstra <peterz@infradead.org> Acked-by: NMichal Hocko <mhocko@suse.cz> Acked-by: NLi Zefan <lizefan@huawei.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Balbir Singh <bsingharora@gmail.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
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- 08 2月, 2014 1 次提交
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由 Tejun Heo 提交于
cgroup_subsys is a bit messier than it needs to be. * The name of a subsys can be different from its internal identifier defined in cgroup_subsys.h. Most subsystems use the matching name but three - cpu, memory and perf_event - use different ones. * cgroup_subsys_id enums are postfixed with _subsys_id and each cgroup_subsys is postfixed with _subsys. cgroup.h is widely included throughout various subsystems, it doesn't and shouldn't have claim on such generic names which don't have any qualifier indicating that they belong to cgroup. * cgroup_subsys->subsys_id should always equal the matching cgroup_subsys_id enum; however, we require each controller to initialize it and then BUG if they don't match, which is a bit silly. This patch cleans up cgroup_subsys names and initialization by doing the followings. * cgroup_subsys_id enums are now postfixed with _cgrp_id, and each cgroup_subsys with _cgrp_subsys. * With the above, renaming subsys identifiers to match the userland visible names doesn't cause any naming conflicts. All non-matching identifiers are renamed to match the official names. cpu_cgroup -> cpu mem_cgroup -> memory perf -> perf_event * controllers no longer need to initialize ->subsys_id and ->name. They're generated in cgroup core and set automatically during boot. * Redundant cgroup_subsys declarations removed. * While updating BUG_ON()s in cgroup_init_early(), convert them to WARN()s. BUGging that early during boot is stupid - the kernel can't print anything, even through serial console and the trap handler doesn't even link stack frame properly for back-tracing. This patch doesn't introduce any behavior changes. v2: Rebased on top of fe1217c4 ("net: net_cls: move cgroupfs classid handling into core"). Signed-off-by: NTejun Heo <tj@kernel.org> Acked-by: NNeil Horman <nhorman@tuxdriver.com> Acked-by: N"David S. Miller" <davem@davemloft.net> Acked-by: N"Rafael J. Wysocki" <rjw@rjwysocki.net> Acked-by: NMichal Hocko <mhocko@suse.cz> Acked-by: NPeter Zijlstra <peterz@infradead.org> Acked-by: NAristeu Rozanski <aris@redhat.com> Acked-by: NIngo Molnar <mingo@redhat.com> Acked-by: NLi Zefan <lizefan@huawei.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Balbir Singh <bsingharora@gmail.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Serge E. Hallyn <serue@us.ibm.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Thomas Graf <tgraf@suug.ch>
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- 21 11月, 2013 1 次提交
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由 Hong Zhiguo 提交于
While u64_stats_fetch_retry is only preempt_disable on 32bit UP system. This is not enough to avoid preemption by bh and may read strange 64 bit value. Signed-off-by: NHong Zhiguo <zhiguohong@tencent.com> Acked-by: NTejun Heo <tj@kernel.org> Cc: stable@kernel.org Signed-off-by: NJens Axboe <axboe@kernel.dk>
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- 13 11月, 2013 1 次提交
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由 Peter Zijlstra 提交于
Now that seqcounts are lockdep enabled objects, we need to explicitly initialize runtime allocated seqcounts so that lockdep can track them. Without this patch, Fengguang was seeing: [ 4.127282] INFO: trying to register non-static key. [ 4.128027] the code is fine but needs lockdep annotation. [ 4.128027] turning off the locking correctness validator. [ 4.128027] CPU: 0 PID: 96 Comm: kworker/u4:1 Not tainted 3.12.0-next-20131108-10601-gbad570d #2 [ 4.128027] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ ... ] [ 4.128027] Call Trace: [ 4.128027] [<7908e744>] ? console_unlock+0x353/0x380 [ 4.128027] [<79dc7cf2>] dump_stack+0x48/0x60 [ 4.128027] [<7908953e>] __lock_acquire.isra.26+0x7e3/0xceb [ 4.128027] [<7908a1c5>] lock_acquire+0x71/0x9a [ 4.128027] [<794079aa>] ? blk_throtl_bio+0x1c3/0x485 [ 4.128027] [<7940658b>] throtl_update_dispatch_stats+0x7c/0x153 [ 4.128027] [<794079aa>] ? blk_throtl_bio+0x1c3/0x485 [ 4.128027] [<794079aa>] blk_throtl_bio+0x1c3/0x485 ... Use u64_stats_init() for all affected data structures, which initializes the seqcount. Reported-and-Tested-by: NFengguang Wu <fengguang.wu@intel.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: NPeter Zijlstra <peterz@infradead.org> [ Folded in another fix from the mailing list as well as a fix to that fix. Tweaked commit message. ] Signed-off-by: NJohn Stultz <john.stultz@linaro.org> Signed-off-by: NPeter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1384314134-6895-1-git-send-email-john.stultz@linaro.org [ So I actually think that the two SOBs from PeterZ are the right depiction of the patch route. ] Signed-off-by: NIngo Molnar <mingo@kernel.org>
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