The mem_dump_obj() functionality adds a few hundred bytes, which is a
small price to pay. Except on kernels built with CONFIG_PRINTK=n, in
which mem_dump_obj() messages will be suppressed. This commit therefore
makes mem_dump_obj() be a static inline empty function on kernels built
with CONFIG_PRINTK=n and excludes all of its support functions as well.
This avoids kernel bloat on systems that cannot use mem_dump_obj().
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <linux-mm@kvack.org>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Pull RCU updates from Paul E. McKenney:
- Documentation updates.
- Miscellaneous fixes.
- kfree_rcu() updates: Addition of mem_dump_obj() to provide allocator return
addresses to more easily locate bugs. This has a couple of RCU-related commits,
but is mostly MM. Was pulled in with akpm's agreement.
- Per-callback-batch tracking of numbers of callbacks,
which enables better debugging information and smarter
reactions to large numbers of callbacks.
- The first round of changes to allow CPUs to be runtime switched from and to
callback-offloaded state.
- CONFIG_PREEMPT_RT-related changes.
- RCU CPU stall warning updates.
- Addition of polling grace-period APIs for SRCU.
- Torture-test and torture-test scripting updates, including a "torture everything"
script that runs rcutorture, locktorture, scftorture, rcuscale, and refscale.
Plus does an allmodconfig build.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit adds vmalloc() support to mem_dump_obj(). Note that the
vmalloc_dump_obj() function combines the checking and dumping, in
contrast with the split between kmem_valid_obj() and kmem_dump_obj().
The reason for the difference is that the checking in the vmalloc()
case involves acquiring a global lock, and redundant acquisitions of
global locks should be avoided, even on not-so-fast paths.
Note that this change causes on-stack variables to be reported as
vmalloc() storage from kernel_clone() or similar, depending on the degree
of inlining that your compiler does. This is likely more helpful than
the earlier "non-paged (local) memory".
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <linux-mm@kvack.org>
Reported-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
A current "lazy drain" model suffers from at least two issues.
First one is related to the unsorted list of vmap areas, thus in order to
identify the [min:max] range of areas to be drained, it requires a full
list scan. What is a time consuming if the list is too long.
Second one and as a next step is about merging all fragments with a free
space. What is also a time consuming because it has to iterate over
entire list which holds outstanding lazy areas.
See below the "preemptirqsoff" tracer that illustrates a high latency. It
is ~24676us. Our workloads like audio and video are effected by such long
latency:
<snip>
tracer: preemptirqsoff
preemptirqsoff latency trace v1.1.5 on 4.9.186-perf+
--------------------------------------------------------------------
latency: 24676 us, #4/4, CPU#1 | (M:preempt VP:0, KP:0, SP:0 HP:0 P:8)
-----------------
| task: crtc_commit:112-261 (uid:0 nice:0 policy:1 rt_prio:16)
-----------------
=> started at: __purge_vmap_area_lazy
=> ended at: __purge_vmap_area_lazy
_------=> CPU#
/ _-----=> irqs-off
| / _----=> need-resched
|| / _---=> hardirq/softirq
||| / _--=> preempt-depth
|||| / delay
cmd pid ||||| time | caller
\ / ||||| \ | /
crtc_com-261 1...1 1us*: _raw_spin_lock <-__purge_vmap_area_lazy
[...]
crtc_com-261 1...1 24675us : _raw_spin_unlock <-__purge_vmap_area_lazy
crtc_com-261 1...1 24677us : trace_preempt_on <-__purge_vmap_area_lazy
crtc_com-261 1...1 24683us : <stack trace>
=> free_vmap_area_noflush
=> remove_vm_area
=> __vunmap
=> vfree
=> drm_property_free_blob
=> drm_mode_object_unreference
=> drm_property_unreference_blob
=> __drm_atomic_helper_crtc_destroy_state
=> sde_crtc_destroy_state
=> drm_atomic_state_default_clear
=> drm_atomic_state_clear
=> drm_atomic_state_free
=> complete_commit
=> _msm_drm_commit_work_cb
=> kthread_worker_fn
=> kthread
=> ret_from_fork
<snip>
To address those two issues we can redesign a purging of the outstanding
lazy areas. Instead of queuing vmap areas to the list, we replace it by
the separate rb-tree. In hat case an area is located in the tree/list in
ascending order. It will give us below advantages:
a) Outstanding vmap areas are merged creating bigger coalesced blocks,
thus it becomes less fragmented.
b) It is possible to calculate a flush range [min:max] without scanning
all elements. It is O(1) access time or complexity;
c) The final merge of areas with the rb-tree that represents a free
space is faster because of (a). As a result the lock contention is
also reduced.
Link: https://lkml.kernel.org/r/20201116220033.1837-2-urezki@gmail.com
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: huang ying <huang.ying.caritas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Track at which levels in the page-table entries were modified by
vmap/vunmap.
After the page-table has been modified, use that information do decide
whether the new arch_sync_kernel_mappings() needs to be called.
[akpm@linux-foundation.org: map_kernel_range_noflush() needs the arch_sync_kernel_mappings() call]
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Link: http://lkml.kernel.org/r/20200515140023.25469-3-joro@8bytes.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Open code it in __bpf_map_area_alloc, which is the only caller. Also
clean up __bpf_map_area_alloc to have a single vmalloc call with slightly
different flags instead of the current two different calls.
For this to compile for the nommu case add a __vmalloc_node_range stub to
nommu.c.
[akpm@linux-foundation.org: fix nommu.c build]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: Gao Xiang <xiang@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Kelley <mikelley@microsoft.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Wei Liu <wei.liu@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Link: http://lkml.kernel.org/r/20200414131348.444715-27-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Just use __vmalloc_node instead which gets and extra argument. To be able
to to use __vmalloc_node in all caller make it available outside of
vmalloc and implement it in nommu.c.
[akpm@linux-foundation.org: fix nommu build]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: Gao Xiang <xiang@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Kelley <mikelley@microsoft.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Wei Liu <wei.liu@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Link: http://lkml.kernel.org/r/20200414131348.444715-25-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
