lkml.org 
[lkml]   [2022]   [Jun]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v3 18/21] gup: add FOLL_HINT_BULK, FAULT_FLAG_NON_CACHING
Date
Add FOLL_HINT_BULK, which callers of get_user_pages(), pin_user_pages()
can use to signal that this call is one of many, allowing
get_user_pages() to optimize accordingly.

Additionally, add FAULT_FLAG_NON_CACHING, which in the fault handling
path signals that the underlying logic can use non-caching primitives.
This is a possible optimization for FOLL_HINT_BULK calls.

Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com>
---
include/linux/mm.h | 1 +
include/linux/mm_types.h | 2 ++
2 files changed, 3 insertions(+)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index a9b0c1889348..dbd8b7344dfc 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2941,6 +2941,7 @@ struct page *follow_page(struct vm_area_struct *vma, unsigned long address,
#define FOLL_SPLIT_PMD 0x20000 /* split huge pmd before returning */
#define FOLL_PIN 0x40000 /* pages must be released via unpin_user_page */
#define FOLL_FAST_ONLY 0x80000 /* gup_fast: prevent fall-back to slow gup */
+#define FOLL_HINT_BULK 0x100000 /* part of a larger extent being gup'd */

/*
* FOLL_PIN and FOLL_LONGTERM may be used in various combinations with each
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index b34ff2cdbc4f..287b3018c14d 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -824,6 +824,7 @@ typedef struct {
* mapped R/O.
* @FAULT_FLAG_ORIG_PTE_VALID: whether the fault has vmf->orig_pte cached.
* We should only access orig_pte if this flag set.
+ * @FAULT_FLAG_NON_CACHING: Avoid polluting the cache if possible.
*
* About @FAULT_FLAG_ALLOW_RETRY and @FAULT_FLAG_TRIED: we can specify
* whether we would allow page faults to retry by specifying these two
@@ -861,6 +862,7 @@ enum fault_flag {
FAULT_FLAG_INTERRUPTIBLE = 1 << 9,
FAULT_FLAG_UNSHARE = 1 << 10,
FAULT_FLAG_ORIG_PTE_VALID = 1 << 11,
+ FAULT_FLAG_NON_CACHING = 1 << 12,
};

typedef unsigned int __bitwise zap_flags_t;
--
2.31.1
\
 
 \ /
  Last update: 2022-06-06 22:47    [W:0.271 / U:0.164 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site