| /kernel/linux/linux-5.10/fs/btrfs/ |
| D | delalloc-space.c | 23 * We call into btrfs_reserve_data_bytes() for the user request bytes that
24 * they wish to write. We make this reservation and add it to
25 * space_info->bytes_may_use. We set EXTENT_DELALLOC on the inode io_tree
27 * make a real allocation if we are pre-allocating or doing O_DIRECT.
30 * At writepages()/prealloc/O_DIRECT time we will call into
31 * btrfs_reserve_extent() for some part or all of this range of bytes. We
35 * may allocate a smaller on disk extent than we previously reserved.
46 * This is the simplest case, we haven't completed our operation and we know
47 * how much we reserved, we can simply call
60 * We keep track of two things on a per inode bases
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| D | space-info.c | 22 * 1) space_info. This is the ultimate arbiter of how much space we can use.
25 * reservations we care about total_bytes - SUM(space_info->bytes_) when
30 * metadata reservation we have. You can see the comment in the block_rsv
34 * 3) btrfs_calc*_size. These are the worst case calculations we used based
35 * on the number of items we will want to modify. We have one for changing
36 * items, and one for inserting new items. Generally we use these helpers to
42 * We call into either btrfs_reserve_data_bytes() or
43 * btrfs_reserve_metadata_bytes(), depending on which we're looking for, with
44 * num_bytes we want to reserve.
61 * Assume we are unable to simply make the reservation because we do not have
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| D | locking.h | 20 * We are limited in number of subclasses by MAX_LOCKDEP_SUBCLASSES, which at
21 * the time of this patch is 8, which is how many we use. Keep this in mind if
28 * When we COW a block we are holding the lock on the original block,
30 * when we lock the newly allocated COW'd block. Handle this by having
36 * Oftentimes we need to lock adjacent nodes on the same level while
37 * still holding the lock on the original node we searched to, such as
40 * Because of this we need to indicate to lockdep that this is
48 * When splitting we will be holding a lock on the left/right node when
49 * we need to cow that node, thus we need a new set of subclasses for
56 * When splitting we may push nodes to the left or right, but still use
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| /kernel/linux/linux-6.6/fs/btrfs/ |
| D | space-info.c | 26 * 1) space_info. This is the ultimate arbiter of how much space we can use.
29 * reservations we care about total_bytes - SUM(space_info->bytes_) when
34 * metadata reservation we have. You can see the comment in the block_rsv
38 * 3) btrfs_calc*_size. These are the worst case calculations we used based
39 * on the number of items we will want to modify. We have one for changing
40 * items, and one for inserting new items. Generally we use these helpers to
46 * We call into either btrfs_reserve_data_bytes() or
47 * btrfs_reserve_metadata_bytes(), depending on which we're looking for, with
48 * num_bytes we want to reserve.
65 * Assume we are unable to simply make the reservation because we do not have
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| D | delalloc-space.c | 25 * We call into btrfs_reserve_data_bytes() for the user request bytes that
26 * they wish to write. We make this reservation and add it to
27 * space_info->bytes_may_use. We set EXTENT_DELALLOC on the inode io_tree
29 * make a real allocation if we are pre-allocating or doing O_DIRECT.
32 * At writepages()/prealloc/O_DIRECT time we will call into
33 * btrfs_reserve_extent() for some part or all of this range of bytes. We
37 * may allocate a smaller on disk extent than we previously reserved.
48 * This is the simplest case, we haven't completed our operation and we know
49 * how much we reserved, we can simply call
62 * We keep track of two things on a per inode bases
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| /kernel/linux/linux-5.10/arch/powerpc/mm/nohash/ |
| D | tlb_low_64e.S | 95 /* We need _PAGE_PRESENT and _PAGE_ACCESSED set */
97 /* We do the user/kernel test for the PID here along with the RW test
99 /* We pre-test some combination of permissions to avoid double
102 * We move the ESR:ST bit into the position of _PAGE_BAP_SW in the PTE
107 * writeable, we will take a new fault later, but that should be
110 * We also move ESR_ST in _PAGE_DIRTY position
113 * MAS1 is preset for all we need except for TID that needs to
134 * We are entered with:
182 /* Now we build the MAS:
224 /* We need to check if it was an instruction miss */
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| /kernel/linux/linux-6.6/drivers/md/bcache/ |
| D | journal.h | 9 * never spans two buckets. This means (not implemented yet) we can resize the
15 * We also keep some things in the journal header that are logically part of the
20 * rewritten when we want to move/wear level the main journal.
22 * Currently, we don't journal BTREE_REPLACE operations - this will hopefully be
25 * moving gc we work around it by flushing the btree to disk before updating the
35 * We track this by maintaining a refcount for every open journal entry, in a
38 * zero, we pop it off - thus, the size of the fifo tells us the number of open
41 * We take a refcount on a journal entry when we add some keys to a journal
42 * entry that we're going to insert (held by struct btree_op), and then when we
43 * insert those keys into the btree the btree write we're setting up takes a
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| /kernel/linux/linux-5.10/drivers/md/bcache/ |
| D | journal.h | 9 * never spans two buckets. This means (not implemented yet) we can resize the
15 * We also keep some things in the journal header that are logically part of the
20 * rewritten when we want to move/wear level the main journal.
22 * Currently, we don't journal BTREE_REPLACE operations - this will hopefully be
25 * moving gc we work around it by flushing the btree to disk before updating the
35 * We track this by maintaining a refcount for every open journal entry, in a
38 * zero, we pop it off - thus, the size of the fifo tells us the number of open
41 * We take a refcount on a journal entry when we add some keys to a journal
42 * entry that we're going to insert (held by struct btree_op), and then when we
43 * insert those keys into the btree the btree write we're setting up takes a
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| /kernel/linux/linux-5.10/fs/xfs/ |
| D | xfs_log_cil.c | 24 * recover, so we don't allow failure here. Also, we allocate in a context that
25 * we don't want to be issuing transactions from, so we need to tell the
28 * We don't reserve any space for the ticket - we are going to steal whatever
29 * space we require from transactions as they commit. To ensure we reserve all
30 * the space required, we need to set the current reservation of the ticket to
31 * zero so that we know to steal the initial transaction overhead from the
43 * set the current reservation to zero so we know to steal the basic in xlog_cil_ticket_alloc()
51 * After the first stage of log recovery is done, we know where the head and
52 * tail of the log are. We need this log initialisation done before we can
55 * Here we allocate a log ticket to track space usage during a CIL push. This
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| D | xfs_log_priv.h | 63 * By covering, we mean changing the h_tail_lsn in the last on-disk
72 * might include space beyond the EOF. So if we just push the EOF a
80 * system is idle. We need two dummy transaction because the h_tail_lsn
92 * we are done covering previous transactions.
93 * NEED -- logging has occurred and we need a dummy transaction
95 * DONE -- we were in the NEED state and have committed a dummy
97 * NEED2 -- we detected that a dummy transaction has gone to the
99 * DONE2 -- we committed a dummy transaction when in the NEED2 state.
101 * There are two places where we switch states:
103 * 1.) In xfs_sync, when we detect an idle log and are in NEED or NEED2.
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| /kernel/linux/linux-6.6/fs/xfs/ |
| D | xfs_log_cil.c | 23 * recover, so we don't allow failure here. Also, we allocate in a context that
24 * we don't want to be issuing transactions from, so we need to tell the
27 * We don't reserve any space for the ticket - we are going to steal whatever
28 * space we require from transactions as they commit. To ensure we reserve all
29 * the space required, we need to set the current reservation of the ticket to
30 * zero so that we know to steal the initial transaction overhead from the
42 * set the current reservation to zero so we know to steal the basic in xlog_cil_ticket_alloc()
62 * We can't rely on just the log item being in the CIL, we have to check
80 * current sequence, we're in a new checkpoint. in xlog_item_in_current_chkpt()
140 * We're in the middle of switching cil contexts. Reset the in xlog_cil_push_pcp_aggregate()
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| D | xfs_discard.c | 25 * We need to walk the filesystem free space and issue discards on the free
26 * space that meet the search criteria (size and location). We cannot issue
28 * still marked as busy. To serialise against extent state changes whilst we are
29 * gathering extents to trim, we must hold the AGF lock to lock out other
32 * However, we cannot just hold the AGF for the entire AG free space walk whilst
33 * we issue discards on each free space that is found. Storage devices can have
36 * extent can take a *long* time. Whilst we are doing this walk, nothing else
37 * can access the AGF, and we can stall transactions and hence the log whilst
41 * Hence we need to take a leaf from the bulkstat playbook. It takes the AGI
47 * We can't do this exactly with free space - once we drop the AGF lock, the
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| D | xfs_log_priv.h | 74 * By covering, we mean changing the h_tail_lsn in the last on-disk
83 * might include space beyond the EOF. So if we just push the EOF a
91 * system is idle. We need two dummy transaction because the h_tail_lsn
103 * we are done covering previous transactions.
104 * NEED -- logging has occurred and we need a dummy transaction
106 * DONE -- we were in the NEED state and have committed a dummy
108 * NEED2 -- we detected that a dummy transaction has gone to the
110 * DONE2 -- we committed a dummy transaction when in the NEED2 state.
112 * There are two places where we switch states:
114 * 1.) In xfs_sync, when we detect an idle log and are in NEED or NEED2.
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| /kernel/linux/linux-6.6/net/ipv4/ |
| D | tcp_vegas.c | 15 * o We do not change the loss detection or recovery mechanisms of
19 * only every-other RTT during slow start, we increase during
22 * we use the rate at which ACKs come back as the "actual"
24 * o To speed convergence to the right rate, we set the cwnd
25 * to achieve the right ("actual") rate when we exit slow start.
26 * o To filter out the noise caused by delayed ACKs, we use the
55 /* There are several situations when we must "re-start" Vegas:
60 * o when we send a packet and there is no outstanding
63 * In these circumstances we cannot do a Vegas calculation at the
64 * end of the first RTT, because any calculation we do is using
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| /kernel/linux/linux-5.10/net/ipv4/ |
| D | tcp_vegas.c | 15 * o We do not change the loss detection or recovery mechanisms of
19 * only every-other RTT during slow start, we increase during
22 * we use the rate at which ACKs come back as the "actual"
24 * o To speed convergence to the right rate, we set the cwnd
25 * to achieve the right ("actual") rate when we exit slow start.
26 * o To filter out the noise caused by delayed ACKs, we use the
55 /* There are several situations when we must "re-start" Vegas:
60 * o when we send a packet and there is no outstanding
63 * In these circumstances we cannot do a Vegas calculation at the
64 * end of the first RTT, because any calculation we do is using
[all …]
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| /kernel/linux/linux-6.6/arch/powerpc/mm/nohash/ |
| D | tlb_low_64e.S | 91 /* We need _PAGE_PRESENT and _PAGE_ACCESSED set */
93 /* We do the user/kernel test for the PID here along with the RW test
95 /* We pre-test some combination of permissions to avoid double
98 * We move the ESR:ST bit into the position of _PAGE_BAP_SW in the PTE
103 * writeable, we will take a new fault later, but that should be
106 * We also move ESR_ST in _PAGE_DIRTY position
109 * MAS1 is preset for all we need except for TID that needs to
137 * We are entered with:
176 /* Now we build the MAS:
219 /* We need to check if it was an instruction miss */
[all …]
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| /kernel/linux/linux-6.6/arch/arm64/kvm/hyp/nvhe/ |
| D | tlb.c | 22 * We have two requirements: in __tlb_switch_to_guest()
25 * CPUs, for which a dsb(DOMAIN-st) is what we need, DOMAIN in __tlb_switch_to_guest()
30 * we trapped to EL2 so that we can mess with the MM in __tlb_switch_to_guest()
47 * For CPUs that are affected by ARM 1319367, we need to in __tlb_switch_to_guest()
48 * avoid a host Stage-1 walk while we have the guest's in __tlb_switch_to_guest()
50 * We're guaranteed that the S1 MMU is enabled, so we can in __tlb_switch_to_guest()
62 * ensuring that we always have an ISB, but not two ISBs back in __tlb_switch_to_guest()
90 * We could do so much better if we had the VA as well. in __kvm_tlb_flush_vmid_ipa()
91 * Instead, we invalidate Stage-2 for this IPA, and the in __kvm_tlb_flush_vmid_ipa()
98 * We have to ensure completion of the invalidation at Stage-2, in __kvm_tlb_flush_vmid_ipa()
[all …]
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| /kernel/linux/linux-6.6/Documentation/filesystems/ |
| D | xfs-delayed-logging-design.rst | 15 We begin with an overview of transactions in XFS, followed by describing how
16 transaction reservations are structured and accounted, and then move into how we
18 reservations bounds. At this point we need to explain how relogging works. With
113 individual modification is atomic, the chain is *not atomic*. If we crash half
140 complete, we can explicitly tag a transaction as synchronous. This will trigger
145 throughput to the IO latency limitations of the underlying storage. Instead, we
161 available to write the modification into the journal before we start making
164 log in the worst case. This means that if we are modifying a btree in the
165 transaction, we have to reserve enough space to record a full leaf-to-root split
166 of the btree. As such, the reservations are quite complex because we have to
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| /kernel/linux/linux-6.6/drivers/misc/vmw_vmci/ |
| D | vmci_route.c | 33 * which comes from the VMX, so we know it is coming from a in vmci_route()
36 * To avoid inconsistencies, test these once. We will test in vmci_route()
37 * them again when we do the actual send to ensure that we do in vmci_route()
49 * If this message already came from a guest then we in vmci_route()
57 * We must be acting as a guest in order to send to in vmci_route()
63 /* And we cannot send if the source is the host context. */ in vmci_route()
71 * then they probably mean ANY, in which case we in vmci_route()
87 * If it is not from a guest but we are acting as a in vmci_route()
88 * guest, then we need to send it down to the host. in vmci_route()
89 * Note that if we are also acting as a host then this in vmci_route()
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| /kernel/linux/linux-5.10/drivers/misc/vmw_vmci/ |
| D | vmci_route.c | 33 * which comes from the VMX, so we know it is coming from a in vmci_route()
36 * To avoid inconsistencies, test these once. We will test in vmci_route()
37 * them again when we do the actual send to ensure that we do in vmci_route()
49 * If this message already came from a guest then we in vmci_route()
57 * We must be acting as a guest in order to send to in vmci_route()
63 /* And we cannot send if the source is the host context. */ in vmci_route()
71 * then they probably mean ANY, in which case we in vmci_route()
87 * If it is not from a guest but we are acting as a in vmci_route()
88 * guest, then we need to send it down to the host. in vmci_route()
89 * Note that if we are also acting as a host then this in vmci_route()
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| /kernel/linux/linux-6.6/arch/powerpc/kexec/ |
| D | core_64.c | 45 * Since we use the kernel fault handlers and paging code to in machine_kexec_prepare()
46 * handle the virtual mode, we must make sure no destination in machine_kexec_prepare()
53 /* We also should not overwrite the tce tables */ in machine_kexec_prepare()
86 * We rely on kexec_load to create a lists that properly in copy_segments()
88 * We will still crash if the list is wrong, but at least in copy_segments()
121 * After this call we may not use anything allocated in dynamic in kexec_copy_flush()
129 * we need to clear the icache for all dest pages sometime, in kexec_copy_flush()
146 mb(); /* make sure our irqs are disabled before we say they are */ in kexec_smp_down()
153 * Now every CPU has IRQs off, we can clear out any pending in kexec_smp_down()
171 /* Make sure each CPU has at least made it to the state we need. in kexec_prepare_cpus_wait()
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| /kernel/linux/linux-5.10/arch/powerpc/kexec/ |
| D | core_64.c | 45 * Since we use the kernel fault handlers and paging code to in default_machine_kexec_prepare()
46 * handle the virtual mode, we must make sure no destination in default_machine_kexec_prepare()
53 /* We also should not overwrite the tce tables */ in default_machine_kexec_prepare()
83 * We rely on kexec_load to create a lists that properly in copy_segments()
85 * We will still crash if the list is wrong, but at least in copy_segments()
117 * After this call we may not use anything allocated in dynamic in kexec_copy_flush()
125 * we need to clear the icache for all dest pages sometime, in kexec_copy_flush()
142 mb(); /* make sure our irqs are disabled before we say they are */ in kexec_smp_down()
149 * Now every CPU has IRQs off, we can clear out any pending in kexec_smp_down()
167 /* Make sure each CPU has at least made it to the state we need. in kexec_prepare_cpus_wait()
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| /kernel/linux/linux-5.10/drivers/gpu/drm/i915/ |
| D | i915_request.c | 70 * We could extend the life of a context to beyond that of all in i915_fence_get_timeline_name()
72 * or we just give them a false name. Since in i915_fence_get_timeline_name()
118 * freed when the slab cache itself is freed, and so we would get in i915_fence_release()
127 * We do not hold a reference to the engine here and so have to be in i915_fence_release()
128 * very careful in what rq->engine we poke. The virtual engine is in i915_fence_release()
129 * referenced via the rq->context and we released that ref during in i915_fence_release()
130 * i915_request_retire(), ergo we must not dereference a virtual in i915_fence_release()
131 * engine here. Not that we would want to, as the only consumer of in i915_fence_release()
136 * we know that it will have been processed by the HW and will in i915_fence_release()
142 * power-of-two we assume that rq->engine may still be a virtual in i915_fence_release()
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| /kernel/linux/linux-5.10/fs/xfs/scrub/ |
| D | bitmap.c | 90 * @bitmap as the list of blocks that are not accounted for, which we assume
120 * Now that we've sorted both lists, we iterate bitmap once, rolling in xbitmap_disunion()
121 * forward through sub and/or bitmap as necessary until we find an in xbitmap_disunion()
122 * overlap or reach the end of either list. We do not reset lp to the in xbitmap_disunion()
123 * head of bitmap nor do we reset sub_br to the head of sub. The in xbitmap_disunion()
124 * list traversal is similar to merge sort, but we're deleting in xbitmap_disunion()
125 * instead. In this manner we avoid O(n^2) operations. in xbitmap_disunion()
134 * Advance sub_br and/or br until we find a pair that in xbitmap_disunion()
135 * intersect or we run out of extents. in xbitmap_disunion()
147 /* trim sub_br to fit the extent we have */ in xbitmap_disunion()
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| /kernel/linux/linux-5.10/drivers/usb/dwc2/ |
| D | hcd_queue.c | 61 /* If we get a NAK, wait this long before retrying */
150 * @num_bits: The number of bits we need per period we want to reserve
152 * @interval: How often we need to be scheduled for the reservation this
156 * the interval or we return failure right away.
157 * @only_one_period: Normally we'll allow picking a start anywhere within the
158 * first interval, since we can still make all repetition
160 * here then we'll return failure if we can't fit within
163 * The idea here is that we want to schedule time for repeating events that all
168 * To keep things "simple", we'll represent our schedule with a bitmap that
170 * but does mean that we need to handle things specially (and non-ideally) if
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