函数逻辑报告

Linux Kernel

v5.5.9

Brick Technologies Co., Ltd

Source Code:mm\page_io.c Create Date:2022-07-27 16:44:12
Last Modify:2020-03-12 14:18:49 Copyright©Brick
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函数名称：swap_readpage

函数原型：int swap_readpage(struct page *page, bool synchronous)

返回类型：int

参数：

类型参数名称
struct page *page
boolsynchronous
354  ret等于0
355  sis等于page_swap_info(page)
360  VM_BUG_ON_PAGE(!PageSwapCache(page) && !synchronous, page)
361  VM_BUG_ON_PAGE(!PageLocked(page), page)
362  VM_BUG_ON_PAGE(PageUptodate(page), page)
369  psi_memstall_enter - mark the beginning of a memory stall section*@flags: flags to handle nested sections* Marks the calling task as being stalled due to a lack of memory,* such as waiting for a refault or performing reclaim.
371  如果frontswap_load(page)恒等于0则
372  SetPageUptodate(page)
373  lock_page - unlock a locked page*@page: the page* Unlocks the page and wakes up sleepers in ___wait_on_page_locked().* Also wakes sleepers in wait_on_page_writeback() because the wakeup* mechanism between PageLocked pages and PageWriteback pages is shared.
374  转到:out
377  如果SWP_USED etc: see above 按位与SWP_FS则
378  swap_file等于seldom referenced
379  mapping等于f_mapping
381  ret等于readpage(swap_file, page)
382  如果非ret则Disable counters
384  转到:out
387  ret等于bdev_read_page(swap device or bdev of swap file , swap_page_sector(page), page)
388  如果非ret则
389  如果Return true if the page was successfully locked则
390  swap_slot_free_notify(page)
391  lock_page - unlock a locked page*@page: the page* Unlocks the page and wakes up sleepers in ___wait_on_page_locked().* Also wakes sleepers in wait_on_page_writeback() because the wakeup* mechanism between PageLocked pages and PageWriteback pages is shared.
394  Disable counters
395  转到:out
398  ret等于0
399  bio等于get_swap_bio(GFP_KERNEL, page, end_swap_bio_read)
400  如果(bio == NULL)则
401  lock_page - unlock a locked page*@page: the page* Unlocks the page and wakes up sleepers in ___wait_on_page_locked().* Also wakes sleepers in wait_on_page_writeback() because the wakeup* mechanism between PageLocked pages and PageWriteback pages is shared.
402  ret等于负ENOMEM
403  转到:out
405  disk等于bi_disk
410  bsolete, don't use in new code
411  如果synchronous则
412  bottom bits req flags, * top bits REQ_OP. Use * accessors.或等于REQ_HIPRI
413  get_task_struct(当前进程)
414  bi_private等于当前进程
416  Disable counters
417  get a reference to a bio, so it won't disappear. the intended use is* something like:* bio_get(bio);* submit_bio(rw, bio);* if (bio->bi_flags ...)* do_something* bio_put(bio);* without the bio_get(), it could potentially complete I/O before submit_bio
418  qc等于submit_bio(bio)
419  当synchronous循环
420  set_current_state(深度睡眠态)
421  如果非READ_ONCE(bi_private)则退出
424  如果非blk_poll(queue, qc, true)则io_schedule()
427  set_current_state() includes a barrier so that the write of current->state* is correctly serialised wrt the caller's subsequent test of whether to* actually sleep:* for (;;) {* set_current_state(TASK_UNINTERRUPTIBLE);* if (!need_sleep)* break;* (就绪态)
428  bio_put(bio)
430  out :
431  psi_memstall_leave - mark the end of an memory stall section*@flags: flags to handle nested memdelay sections* Marks the calling task as no longer stalled due to lack of memory.
432  返回:ret
调用者
名称描述
read_swap_cache_asyncLocate a page of swap in physical memory, reserving swap cache space* and reading the disk if it is not already cached.* A failure return means that either the page allocation failed or that* the swap entry is no longer in use.
swap_cluster_readaheadswap_cluster_readahead - swap in pages in hope we need them soon*@entry: swap entry of this memory*@gfp_mask: memory allocation flags*@vmf: fault information* Returns the struct page for entry and addr, after queueing swapin.
swap_vma_readaheadswap_vma_readahead - swap in pages in hope we need them soon*@entry: swap entry of this memory*@gfp_mask: memory allocation flags*@vmf: fault information* Returns the struct page for entry and addr, after queueing swapin.* Primitive swap readahead code
do_swap_pageWe enter with non-exclusive mmap_sem (to exclude vma changes,* but allow concurrent faults), and pte mapped but not yet locked.* We return with pte unmapped and unlocked.* We return with the mmap_sem locked or unlocked in the same cases