- 19 Jan, 2023 40 commits
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Vernon Yang authored
Invert the conditional judgment of the mid_split, to focus the return statement in the last statement, which is easier to understand and for better readability. Link: https://lkml.kernel.org/r/20221221060058.609003-8-vernon2gm@gmail.comSigned-off-by:
Vernon Yang <vernon2gm@gmail.com> Reviewed-by:
Liam R. Howlett <Liam.Howlett@oracle.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org>
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Vernon Yang authored
If mas->node is an MAS_START, there are three cases, and they all assign different values to mas->node and mas->offset. So there is no need to set them to a default value before updating. Update them directly to make them easier to understand and for better readability. Link: https://lkml.kernel.org/r/20221221060058.609003-7-vernon2gm@gmail.comSigned-off-by:
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Vernon Yang authored
The macros CONFIG_DEBUG_MAPLE_TREE_VERBOSE no one uses, functions mas_dup_tree() and mas_dup_store() are not implemented, just function declaration, so drop it. Link: https://lkml.kernel.org/r/20221221060058.609003-6-vernon2gm@gmail.comSigned-off-by:
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Vernon Yang authored
When you need to compare whether node->parent is parent of the root node, using macro MA_ROOT_PARENT is easier to understand and for better readability. Link: https://lkml.kernel.org/r/20221221060058.609003-5-vernon2gm@gmail.comSigned-off-by:
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Vernon Yang authored
Use mt_node_max() to get the maximum number of slots for a node, rather than direct operations mt_max[], makes it better portability. Link: https://lkml.kernel.org/r/20221221060058.609003-4-vernon2gm@gmail.comSigned-off-by:
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Vernon Yang authored
For functions with a return type of void, it is unnecessary to add a reurn statement at the end of the function, so drop it. Link: https://lkml.kernel.org/r/20221221060058.609003-3-vernon2gm@gmail.comSigned-off-by:
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Vernon Yang authored
Patch series "Clean up and refinement for maple tree", v2. This patchset cleans up and refines some maple tree code. A few small changes make the code easier to understand and for better readability. This patch (of 7): These extra space and blank lines are unnecessary, so drop them. Link: https://lkml.kernel.org/r/20221221060058.609003-1-vernon2gm@gmail.com Link: https://lkml.kernel.org/r/20221221060058.609003-2-vernon2gm@gmail.comSigned-off-by:
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Lorenzo Stoakes authored
This function sets __GFP_NOWARN in the gfp_mask rendering the warn_alloc() invocations no-ops. Remove this and instead rely on this flag being set only for the vm_area_alloc_pages() function, ensuring it is cleared for each of the warn_alloc() calls. Link: https://lkml.kernel.org/r/20221219123659.90614-1-lstoakes@gmail.comSigned-off-by:
Lorenzo Stoakes <lstoakes@gmail.com> Reviewed-by:
Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Baoquan He <bhe@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Nicholas Piggin <npiggin@gmail.com> Signed-off-by:
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Jianlin Lv authored
Although when a process terminates, the kernel will removes memory associated with that process, It's neither good style nor proper design to leave it to kernel. This patch free allocated memory before process exit. Link: https://lkml.kernel.org/r/20221219164917.14132-1-iecedge@gmail.comSigned-off-by:
Jianlin Lv <iecedge@gmail.com> Signed-off-by:
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Andrey Konovalov authored
As Hardware Tag-Based KASAN is intended to be used in production, its performance impact is crucial. As page_alloc allocations tend to be big, tagging and checking all such allocations can introduce a significant slowdown. Add two new boot parameters that allow to alleviate that slowdown: - kasan.page_alloc.sample, which makes Hardware Tag-Based KASAN tag only every Nth page_alloc allocation with the order configured by the second added parameter (default: tag every such allocation). - kasan.page_alloc.sample.order, which makes sampling enabled by the first parameter only affect page_alloc allocations with the order equal or greater than the specified value (default: 3, see below). The exact performance improvement caused by using the new parameters depends on their values and the applied workload. The chosen default value for kasan.page_alloc.sample.order is 3, which matches both PAGE_ALLOC_COSTLY_ORDER and SKB_FRAG_PAGE_ORDER. This is done for two reasons: 1. PAGE_ALLOC_COSTLY_ORDER is "the order at which allocations are deemed costly to service", which corresponds to the idea that only large and thus costly allocations are supposed to sampled. 2. One of the workloads targeted by this patch is a benchmark that sends a large amount of data over a local loopback connection. Most multi-page data allocations in the networking subsystem have the order of SKB_FRAG_PAGE_ORDER (or PAGE_ALLOC_COSTLY_ORDER). When running a local loopback test on a testing MTE-enabled device in sync mode, enabling Hardware Tag-Based KASAN introduces a ~50% slowdown. Applying this patch and setting kasan.page_alloc.sampling to a value higher than 1 allows to lower the slowdown. The performance improvement saturates around the sampling interval value of 10 with the default sampling page order of 3. This lowers the slowdown to ~20%. The slowdown in real scenarios involving the network will likely be better. Enabling page_alloc sampling has a downside: KASAN misses bad accesses to a page_alloc allocation that has not been tagged. This lowers the value of KASAN as a security mitigation. However, based on measuring the number of page_alloc allocations of different orders during boot in a test build, sampling with the default kasan.page_alloc.sample.order value affects only ~7% of allocations. The rest ~93% of allocations are still checked deterministically. Link: https://lkml.kernel.org/r/129da0614123bb85ed4dd61ae30842b2dd7c903f.1671471846.git.andreyknvl@google.comSigned-off-by:
Andrey Konovalov <andreyknvl@google.com> Reviewed-by:
Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Jann Horn <jannh@google.com> Cc: Mark Brand <markbrand@google.com> Cc: Peter Collingbourne <pcc@google.com> Signed-off-by:
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Kairui Song authored
All its callers either already hold a reference to, or lock the swap device while calling this function. There is only one exception in shmem_swapin_folio, just make this caller also hold a reference of the swap device, so this helper can be simplified and saves a few cycles. This also provides finer control of error handling in shmem_swapin_folio, on race (with swap off), it can just try again. For invalid swap entry, it can fail with a proper error code. Link: https://lkml.kernel.org/r/20221219185840.25441-5-ryncsn@gmail.comSigned-off-by:
Kairui Song <kasong@tencent.com> Cc: David Hildenbrand <david@redhat.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by:
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Kairui Song authored
This makes the code cleaner. This helper is made of only two line of self explanational code and not reused anywhere else. And this actually make the compiled object smaller by a bit. bloat-o-meter results on x86_64 of mm/swap_state.o: add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-35 (-35) Function old new delta swap_ra_info.constprop 512 477 -35 Total: Before=8388, After=8353, chg -0.42% Link: https://lkml.kernel.org/r/20221219185840.25441-4-ryncsn@gmail.comSigned-off-by:
"Huang, Ying" <ying.huang@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by:
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Kairui Song authored
Avoid a redundant pte map/unmap when swap readahead window is 1. Link: https://lkml.kernel.org/r/20221219185840.25441-3-ryncsn@gmail.comSigned-off-by:
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Kairui Song authored
Patch series "Clean up and fixes for swap", v2. This series cleans up some code paths, saves a few cycles and reduces the object size by a bit. It also fixes some rare race issue with statistics. This patch (of 4): Convert a volatile variable to more readable READ_ONCE. And this actually avoids the code from reading the variable twice redundantly when it races. Link: https://lkml.kernel.org/r/20221219185840.25441-1-ryncsn@gmail.com Link: https://lkml.kernel.org/r/20221219185840.25441-2-ryncsn@gmail.comSigned-off-by:
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SeongJae Park authored
Document newly added DAMON sysfs interface files for DAMOS filtering on the DAMON ABI document. Link: https://lkml.kernel.org/r/20221205230830.144349-12-sj@kernel.orgSigned-off-by:
SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by:
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SeongJae Park authored
Document about the newly added files for DAMOS filters on the DAMON usage document. Link: https://lkml.kernel.org/r/20221205230830.144349-11-sj@kernel.orgSigned-off-by:
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SeongJae Park authored
Add simple test cases for scheme filters of DAMON sysfs interface. The test cases check if the files are populated as expected, receives some valid inputs, and refuses some invalid inputs. Link: https://lkml.kernel.org/r/20221205230830.144349-10-sj@kernel.orgSigned-off-by:
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SeongJae Park authored
Implement scheme filters functionality of DAMON sysfs interface by making the code reads the values of files under the filter directories and pass that to DAMON using DAMON kernel API. [sj@kernel.org: fix leaking a filter for wrong cgroup path] Link: https://lkml.kernel.org/r/20221219171807.55708-2-sj@kernel.org [sj@kernel.org: return an error for filter memcg path id lookup failure] Link: https://lkml.kernel.org/r/20221219171807.55708-3-sj@kernel.org Link: https://lkml.kernel.org/r/20221205230830.144349-9-sj@kernel.orgSigned-off-by:
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SeongJae Park authored
Implement 'nr_filters' file under 'filters' directory, which will be used to populate specific number of 'filter' directory under the directory, similar to other 'nr_*' files in DAMON sysfs interface. Link: https://lkml.kernel.org/r/20221205230830.144349-8-sj@kernel.orgSigned-off-by:
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SeongJae Park authored
Implement DAMOS filter directory which will be located under the filters directory. The directory provides three files, namely type, matching, and memcg_path. 'type' and 'matching' will be directly connected to the fields of 'struct damos_filter' having same name. 'memcg_path' will receive the path of the memory cgroup of the interest and later converted to memcg id when it's committed. Link: https://lkml.kernel.org/r/20221205230830.144349-7-sj@kernel.orgSigned-off-by:
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SeongJae Park authored
DAMOS filters are currently supported by only DAMON kernel API. To expose the feature to user space, implement a DAMON sysfs directory named 'filters' under each scheme directory. Please note that this is implementing only the directory. Following commits will implement more files and directories, and finally connect the DAMOS filters feature. Link: https://lkml.kernel.org/r/20221205230830.144349-6-sj@kernel.orgSigned-off-by:
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SeongJae Park authored
Document the newly added 'skip_anon' parameter of DAMON_RECLAIM, which can be used to avoid anonymous pages reclamation. Link: https://lkml.kernel.org/r/20221205230830.144349-5-sj@kernel.orgSigned-off-by:
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SeongJae Park authored
In some cases, for example if users have confidence at anonymous pages management or the swap device is too slow, users would want to avoid DAMON_RECLAIM swapping the anonymous pages out. For such case, add yet another DAMON_RECLAIM parameter, namely 'skip_anon'. When it is set as 'Y', DAMON_RECLAIM will avoid reclaiming anonymous pages using a DAMOS filter. Link: https://lkml.kernel.org/r/20221205230830.144349-4-sj@kernel.orgSigned-off-by:
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SeongJae Park authored
Implement support of the DAMOS filters in the physical address space monitoring operations set, for all DAMOS actions that it supports including 'pageout', 'lru_prio', and 'lru_deprio'. Link: https://lkml.kernel.org/r/20221205230830.144349-3-sj@kernel.orgSigned-off-by:
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SeongJae Park authored
Patch series "implement DAMOS filtering for anon pages and/or specific memory cgroups" DAMOS let users do system operations in a data access pattern oriented way. The data access pattern, which is extracted by DAMON, is somewhat accurate more than what user space could know in many cases. However, in some situation, users could know something more than the kernel about the pattern or some special requirements for some types of memory or processes. For example, some users would have slow swap devices and knows latency-ciritical processes and therefore want to use DAMON-based proactive reclamation (DAMON_RECLAIM) for only non-anonymous pages of non-latency-critical processes. For such restriction, users could exclude the memory regions from the initial monitoring regions and use non-dynamic monitoring regions update monitoring operations set including fvaddr and paddr. They could also adjust the DAMOS target access pattern. For dynamically changing memory layout and access pattern, those would be not enough. To help the case, add an interface, namely DAMOS filters, which can be used to avoid the DAMOS actions be applied to specific types of memory, to DAMON kernel API (damon.h). At the moment, it supports filtering anonymous pages and/or specific memory cgroups in or out for each DAMOS scheme. This patchset adds the support for all DAMOS actions that 'paddr' monitoring operations set supports ('pageout', 'lru_prio', and 'lru_deprio'), and the functionality is exposed via DAMON kernel API (damon.h) the DAMON sysfs interface (/sys/kernel/mm/damon/admins/), and DAMON_RECLAIM module parameters. Patches Sequence ---------------- First patch implements DAMOS filter interface to DAMON kernel API. Second patch makes the physical address space monitoring operations set to support the filters from all supporting DAMOS actions. Third patch adds anonymous pages filter support to DAMON_RECLAIM, and the fourth patch documents the DAMON_RECLAIM's new feature. Fifth to seventh patches implement DAMON sysfs files for support of the filters, and eighth patch connects the file to use DAMOS filters feature. Ninth patch adds simple self test cases for DAMOS filters of the sysfs interface. Finally, following two patches (tenth and eleventh) document the new features and interfaces. This patch (of 11): DAMOS lets users do system operation in a data access pattern oriented way. The data access pattern, which is extracted by DAMON, is somewhat accurate more than what user space could know in many cases. However, in some situation, users could know something more than the kernel about the pattern or some special requirements for some types of memory or processes. For example, some users would have slow swap devices and knows latency-ciritical processes and therefore want to use DAMON-based proactive reclamation (DAMON_RECLAIM) for only non-anonymous pages of non-latency-critical processes. For such restriction, users could exclude the memory regions from the initial monitoring regions and use non-dynamic monitoring regions update monitoring operations set including fvaddr and paddr. They could also adjust the DAMOS target access pattern. For dynamically changing memory layout and access pattern, those would be not enough. To help the case, add an interface, namely DAMOS filters, which can be used to avoid the DAMOS actions be applied to specific types of memory, to DAMON kernel API (damon.h). At the moment, it supports filtering anonymous pages and/or specific memory cgroups in or out for each DAMOS scheme. Note that this commit adds only the interface to the DAMON kernel API. The impelmentation should be made in the monitoring operations sets, and following commits will add that. Link: https://lkml.kernel.org/r/20221205230830.144349-1-sj@kernel.org Link: https://lkml.kernel.org/r/20221205230830.144349-2-sj@kernel.orgSigned-off-by: -
Johannes Weiner authored
Charge moving mode in cgroup1 allows memory to follow tasks as they migrate between cgroups. This is, and always has been, a questionable thing to do - for several reasons. First, it's expensive. Pages need to be identified, locked and isolated from various MM operations, and reassigned, one by one. Second, it's unreliable. Once pages are charged to a cgroup, there isn't always a clear owner task anymore. Cache isn't moved at all, for example. Mapped memory is moved - but if trylocking or isolating a page fails, it's arbitrarily left behind. Frequent moving between domains may leave a task's memory scattered all over the place. Third, it isn't really needed. Launcher tasks can kick off workload tasks directly in their target cgroup. Using dedicated per-workload groups allows fine-grained policy adjustments - no need to move tasks and their physical pages between control domains. The feature was never forward-ported to cgroup2, and it hasn't been missed. Despite it being a niche usecase, the maintenance overhead of supporting it is enormous. Because pages are moved while they are live and subject to various MM operations, the synchronization rules are complicated. There are lock_page_memcg() in MM and FS code, which non-cgroup people don't understand. In some cases we've been able to shift code and cgroup API calls around such that we can rely on native locking as much as possible. But that's fragile, and sometimes we need to hold MM locks for longer than we otherwise would (pte lock e.g.). Mark the feature deprecated. Hopefully we can remove it soon. And backport into -stable kernels so that people who develop against earlier kernels are warned about this deprecation as early as possible. [akpm@linux-foundation.org: fix memory.rst underlining] Link: https://lkml.kernel.org/r/Y5COd+qXwk/S+n8N@cmpxchg.orgSigned-off-by:
Johannes Weiner <hannes@cmpxchg.org> Acked-by:
Shakeel Butt <shakeelb@google.com> Acked-by:
Hugh Dickins <hughd@google.com> Acked-by:
Michal Hocko <mhocko@suse.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: <stable@vger.kernel.org> Signed-off-by:
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Johannes Weiner authored
The previous patch made sure charge moving only touches pages for which page_mapped() is stable. lock_page_memcg() is no longer needed. Link: https://lkml.kernel.org/r/20221206171340.139790-3-hannes@cmpxchg.orgSigned-off-by:
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Johannes Weiner authored
Patch series "mm: push down lock_page_memcg()", v2. This patch (of 3): During charge moving, the pte lock and the page lock cover nearly all cases of stabilizing page_mapped(). The only exception is when we're looking at a non-present pte and find a page in the page cache or in the swapcache: if the page is mapped elsewhere, it can become unmapped outside of our control. For this reason, rmap needs lock_page_memcg(). We don't like cgroup-specific locks in generic MM code - especially in performance-critical MM code - and for a legacy feature that's unlikely to have many users left - if any. So remove the exception. Arguably that's better semantics anyway: the page is shared, and another process seems to be the more active user. Once we stop moving such pages, rmap doesn't need lock_page_memcg() anymore. The next patch will remove it. Link: https://lkml.kernel.org/r/20221206171340.139790-1-hannes@cmpxchg.org Link: https://lkml.kernel.org/r/20221206171340.139790-2-hannes@cmpxchg.orgSigned-off-by:
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Mike Kravetz authored
With the gcc 'maybe-uninitialized' warning enabled, gcc will produce: mm/hugetlb.c:6896:20: warning: `chg' may be used uninitialized This is a false positive, but may be difficult for the compiler to determine. maybe-uninitialized is disabled by default, but this gets flagged as a 0-DAY build regression. Initialize the variable to silence the warning. Link: https://lkml.kernel.org/r/20221216224507.106789-1-mike.kravetz@oracle.comSigned-off-by:
Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by:
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Kefeng Wang authored
mark_page_lazyfree() and the callers are converted to use folio, this rename and make it to take in a folio argument instead of calling page_folio(). Link: https://lkml.kernel.org/r/20221209020618.190306-1-wangkefeng.wang@huawei.comSigned-off-by:
Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by:
Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by:
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Kefeng Wang authored
Using folios instead of pages removes several calls to compound_head(), Link: https://lkml.kernel.org/r/20221207023431.151008-1-wangkefeng.wang@huawei.comSigned-off-by:
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Wenchao Hao authored
The result of the allocation attempt is not printed in trace_cma_alloc_finish, but it's important to do it so we can set filters to catch specific errors on allocation or to trigger some operations on specific errors. We have printed the result in log, but the log is conditional and could not be filtered by tracing events. It introduces little overhead to print this result. The result of allocation is named `errorno' in the trace. Link: https://lkml.kernel.org/r/20221208142130.1501195-1-haowenchao@huawei.comSigned-off-by:
Wenchao Hao <haowenchao@huawei.com> Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by:
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Qinglin Pan authored
Add a parameter `use_huge' for fix_size_alloc_test(), which can be used to test allocation vie vmalloc_huge for both functionality and performance. Link: https://lkml.kernel.org/r/20221212055657.698420-1-panqinglin2020@iscas.ac.cnSigned-off-by:
Qinglin Pan <panqinglin2020@iscas.ac.cn> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Signed-off-by:
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Michal Hocko authored
set_mempolicy_home_node tries to duplicate a memory policy before checking it whether it is applicable for the operation. There is no real reason for doing that and it might actually be a pointless memory allocation and deallocation exercise for MPOL_INTERLEAVE. Not a big problem but we can do better. Simply check the policy before acting on it. Link: https://lkml.kernel.org/r/20221216194537.238047-2-mathieu.desnoyers@efficios.comSigned-off-by:
Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by:
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Matthew Wilcox (Oracle) authored
Remove this conversion of a folio back to a page. Link: https://lkml.kernel.org/r/20221215214402.3522366-13-willy@infradead.orgSigned-off-by:
Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by:
Jan Kara <jack@suse.cz> Signed-off-by:
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Matthew Wilcox (Oracle) authored
These places just use b_page to get to the buffer's address_space or call page_folio() on b_page to get a folio. Link: https://lkml.kernel.org/r/20221215214402.3522366-12-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
These places just use b_page to get to the buffer's address_space or the index of the page the buffer is in. Link: https://lkml.kernel.org/r/20221215214402.3522366-11-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
These places just use b_page to get to the buffer's address_space or have already been converted to folio. Link: https://lkml.kernel.org/r/20221215214402.3522366-10-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
These places just use b_page to get to the buffer's address_space. Link: https://lkml.kernel.org/r/20221215214402.3522366-9-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
Removes about four calls to compound_head(). Two of them are inline which removes 132 bytes from the kernel text. Link: https://lkml.kernel.org/r/20221215214402.3522366-8-willy@infradead.orgSigned-off-by:
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