diff options
| author | Brian Atkinson <[email protected]> | 2022-03-14 13:37:39 -0600 |
|---|---|---|
| committer | GitHub <[email protected]> | 2022-03-14 12:37:39 -0700 |
| commit | becc717f6143caf80bad6879b6c6402538ecae89 (patch) | |
| tree | bfca8c4127635dbb2041877808991a71c75b25ea /module/os | |
| parent | dad2b19fffda43894a005a042055e268fe6b32e3 (diff) | |
Adding ZERO_PAGE detection
On some architectures ZERO_PAGE is unavailable because it references
a GPL exported symbol of empty_zero_page. Originally e08b993 removed
the call to PAGE_ZERO(0) for assignment to the abd_zero_page. However,
a simple check can be done to avoid a kernel allocation and free for
the abd_zero_page if ZERO_PAGE is available.
Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by: Brian Atkinson <[email protected]>
Closes #13199
Diffstat (limited to 'module/os')
| -rw-r--r-- | module/os/linux/zfs/abd_os.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/module/os/linux/zfs/abd_os.c b/module/os/linux/zfs/abd_os.c index 113aee585..688458621 100644 --- a/module/os/linux/zfs/abd_os.c +++ b/module/os/linux/zfs/abd_os.c @@ -182,8 +182,11 @@ abd_t *abd_zero_scatter = NULL; struct page; /* - * abd_zero_page we will be an allocated zero'd PAGESIZE buffer, which is - * assigned to set each of the pages of abd_zero_scatter. + * _KERNEL - Will point to ZERO_PAGE if it is available or it will be + * an allocated zero'd PAGESIZE buffer. + * Userspace - Will be an allocated zero'ed PAGESIZE buffer. + * + * abd_zero_page is assigned to each of the pages of abd_zero_scatter. */ static struct page *abd_zero_page = NULL; @@ -466,15 +469,19 @@ abd_alloc_zero_scatter(void) struct scatterlist *sg = NULL; struct sg_table table; gfp_t gfp = __GFP_NOWARN | GFP_NOIO; - gfp_t gfp_zero_page = gfp | __GFP_ZERO; int nr_pages = abd_chunkcnt_for_bytes(SPA_MAXBLOCKSIZE); int i = 0; +#if defined(HAVE_ZERO_PAGE_GPL_ONLY) + gfp_t gfp_zero_page = gfp | __GFP_ZERO; while ((abd_zero_page = __page_cache_alloc(gfp_zero_page)) == NULL) { ABDSTAT_BUMP(abdstat_scatter_page_alloc_retry); schedule_timeout_interruptible(1); } abd_mark_zfs_page(abd_zero_page); +#else + abd_zero_page = ZERO_PAGE(0); +#endif /* HAVE_ZERO_PAGE_GPL_ONLY */ while (sg_alloc_table(&table, nr_pages, gfp)) { ABDSTAT_BUMP(abdstat_scatter_sg_table_retry); @@ -695,8 +702,10 @@ abd_free_zero_scatter(void) abd_zero_scatter = NULL; ASSERT3P(abd_zero_page, !=, NULL); #if defined(_KERNEL) +#if defined(HAVE_ZERO_PAGE_GPL_ONLY) abd_unmark_zfs_page(abd_zero_page); __free_page(abd_zero_page); +#endif /* HAVE_ZERO_PAGE_GPL_ONLY */ #else umem_free(abd_zero_page, PAGESIZE); #endif /* _KERNEL */ |