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Message-Id: <1412356087-16115-6-git-send-email-aarcange@redhat.com>
Date: Fri, 3 Oct 2014 19:07:55 +0200
From: Andrea Arcangeli <aarcange@...hat.com>
To: qemu-devel@...gnu.org, kvm@...r.kernel.org,
linux-kernel@...r.kernel.org, linux-mm@...ck.org,
linux-api@...r.kernel.org
Cc: Linus Torvalds <torvalds@...ux-foundation.org>,
Andres Lagar-Cavilla <andreslc@...gle.com>,
Dave Hansen <dave@...1.net>,
Paolo Bonzini <pbonzini@...hat.com>,
Rik van Riel <riel@...hat.com>, Mel Gorman <mgorman@...e.de>,
Andy Lutomirski <luto@...capital.net>,
Andrew Morton <akpm@...ux-foundation.org>,
Sasha Levin <sasha.levin@...cle.com>,
Hugh Dickins <hughd@...gle.com>,
Peter Feiner <pfeiner@...gle.com>,
"\\\"Dr. David Alan Gilbert\\\"" <dgilbert@...hat.com>,
Christopher Covington <cov@...eaurora.org>,
Johannes Weiner <hannes@...xchg.org>,
Android Kernel Team <kernel-team@...roid.com>,
Robert Love <rlove@...gle.com>,
Dmitry Adamushko <dmitry.adamushko@...il.com>,
Neil Brown <neilb@...e.de>, Mike Hommey <mh@...ndium.org>,
Taras Glek <tglek@...illa.com>, Jan Kara <jack@...e.cz>,
KOSAKI Motohiro <kosaki.motohiro@...il.com>,
Michel Lespinasse <walken@...gle.com>,
Minchan Kim <minchan@...nel.org>,
Keith Packard <keithp@...thp.com>,
"Huangpeng (Peter)" <peter.huangpeng@...wei.com>,
Isaku Yamahata <yamahata@...inux.co.jp>,
Anthony Liguori <anthony@...emonkey.ws>,
Stefan Hajnoczi <stefanha@...il.com>,
Wenchao Xia <wenchaoqemu@...il.com>,
Andrew Jones <drjones@...hat.com>,
Juan Quintela <quintela@...hat.com>
Subject: [PATCH 05/17] mm: gup: use get_user_pages_fast and get_user_pages_unlocked
Just an optimization.
Signed-off-by: Andrea Arcangeli <aarcange@...hat.com>
---
drivers/dma/iovlock.c | 10 ++--------
drivers/iommu/amd_iommu_v2.c | 6 ++----
drivers/media/pci/ivtv/ivtv-udma.c | 6 ++----
drivers/scsi/st.c | 10 ++--------
drivers/video/fbdev/pvr2fb.c | 5 +----
mm/process_vm_access.c | 7 ++-----
mm/util.c | 10 ++--------
net/ceph/pagevec.c | 9 ++++-----
8 files changed, 17 insertions(+), 46 deletions(-)
diff --git a/drivers/dma/iovlock.c b/drivers/dma/iovlock.c
index bb48a57..12ea7c3 100644
--- a/drivers/dma/iovlock.c
+++ b/drivers/dma/iovlock.c
@@ -95,17 +95,11 @@ struct dma_pinned_list *dma_pin_iovec_pages(struct iovec *iov, size_t len)
pages += page_list->nr_pages;
/* pin pages down */
- down_read(¤t->mm->mmap_sem);
- ret = get_user_pages(
- current,
- current->mm,
+ ret = get_user_pages_fast(
(unsigned long) iov[i].iov_base,
page_list->nr_pages,
1, /* write */
- 0, /* force */
- page_list->pages,
- NULL);
- up_read(¤t->mm->mmap_sem);
+ page_list->pages);
if (ret != page_list->nr_pages)
goto unpin;
diff --git a/drivers/iommu/amd_iommu_v2.c b/drivers/iommu/amd_iommu_v2.c
index 5f578e8..6963b73 100644
--- a/drivers/iommu/amd_iommu_v2.c
+++ b/drivers/iommu/amd_iommu_v2.c
@@ -519,10 +519,8 @@ static void do_fault(struct work_struct *work)
write = !!(fault->flags & PPR_FAULT_WRITE);
- down_read(&fault->state->mm->mmap_sem);
- npages = get_user_pages(NULL, fault->state->mm,
- fault->address, 1, write, 0, &page, NULL);
- up_read(&fault->state->mm->mmap_sem);
+ npages = get_user_pages_unlocked(NULL, fault->state->mm,
+ fault->address, 1, write, 0, &page);
if (npages == 1) {
put_page(page);
diff --git a/drivers/media/pci/ivtv/ivtv-udma.c b/drivers/media/pci/ivtv/ivtv-udma.c
index 7338cb2..96d866b 100644
--- a/drivers/media/pci/ivtv/ivtv-udma.c
+++ b/drivers/media/pci/ivtv/ivtv-udma.c
@@ -124,10 +124,8 @@ int ivtv_udma_setup(struct ivtv *itv, unsigned long ivtv_dest_addr,
}
/* Get user pages for DMA Xfer */
- down_read(¤t->mm->mmap_sem);
- err = get_user_pages(current, current->mm,
- user_dma.uaddr, user_dma.page_count, 0, 1, dma->map, NULL);
- up_read(¤t->mm->mmap_sem);
+ err = get_user_pages_unlocked(current, current->mm,
+ user_dma.uaddr, user_dma.page_count, 0, 1, dma->map);
if (user_dma.page_count != err) {
IVTV_DEBUG_WARN("failed to map user pages, returned %d instead of %d\n",
diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index aff9689..c89dcfa 100644
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -4536,18 +4536,12 @@ static int sgl_map_user_pages(struct st_buffer *STbp,
return -ENOMEM;
/* Try to fault in all of the necessary pages */
- down_read(¤t->mm->mmap_sem);
/* rw==READ means read from drive, write into memory area */
- res = get_user_pages(
- current,
- current->mm,
+ res = get_user_pages_fast(
uaddr,
nr_pages,
rw == READ,
- 0, /* don't force */
- pages,
- NULL);
- up_read(¤t->mm->mmap_sem);
+ pages);
/* Errors and no page mapped should return here */
if (res < nr_pages)
diff --git a/drivers/video/fbdev/pvr2fb.c b/drivers/video/fbdev/pvr2fb.c
index 167cfff..ff81f65 100644
--- a/drivers/video/fbdev/pvr2fb.c
+++ b/drivers/video/fbdev/pvr2fb.c
@@ -686,10 +686,7 @@ static ssize_t pvr2fb_write(struct fb_info *info, const char *buf,
if (!pages)
return -ENOMEM;
- down_read(¤t->mm->mmap_sem);
- ret = get_user_pages(current, current->mm, (unsigned long)buf,
- nr_pages, WRITE, 0, pages, NULL);
- up_read(¤t->mm->mmap_sem);
+ ret = get_user_pages_fast((unsigned long)buf, nr_pages, WRITE, pages);
if (ret < nr_pages) {
nr_pages = ret;
diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c
index 5077afc..b159769 100644
--- a/mm/process_vm_access.c
+++ b/mm/process_vm_access.c
@@ -99,11 +99,8 @@ static int process_vm_rw_single_vec(unsigned long addr,
size_t bytes;
/* Get the pages we're interested in */
- down_read(&mm->mmap_sem);
- pages = get_user_pages(task, mm, pa, pages,
- vm_write, 0, process_pages, NULL);
- up_read(&mm->mmap_sem);
-
+ pages = get_user_pages_unlocked(task, mm, pa, pages,
+ vm_write, 0, process_pages);
if (pages <= 0)
return -EFAULT;
diff --git a/mm/util.c b/mm/util.c
index 093c973..1b93f2d 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -247,14 +247,8 @@ int __weak get_user_pages_fast(unsigned long start,
int nr_pages, int write, struct page **pages)
{
struct mm_struct *mm = current->mm;
- int ret;
-
- down_read(&mm->mmap_sem);
- ret = get_user_pages(current, mm, start, nr_pages,
- write, 0, pages, NULL);
- up_read(&mm->mmap_sem);
-
- return ret;
+ return get_user_pages_unlocked(current, mm, start, nr_pages,
+ write, 0, pages);
}
EXPORT_SYMBOL_GPL(get_user_pages_fast);
diff --git a/net/ceph/pagevec.c b/net/ceph/pagevec.c
index 5550130..5504783 100644
--- a/net/ceph/pagevec.c
+++ b/net/ceph/pagevec.c
@@ -23,17 +23,16 @@ struct page **ceph_get_direct_page_vector(const void __user *data,
if (!pages)
return ERR_PTR(-ENOMEM);
- down_read(¤t->mm->mmap_sem);
while (got < num_pages) {
- rc = get_user_pages(current, current->mm,
- (unsigned long)data + ((unsigned long)got * PAGE_SIZE),
- num_pages - got, write_page, 0, pages + got, NULL);
+ rc = get_user_pages_fast((unsigned long)data +
+ ((unsigned long)got * PAGE_SIZE),
+ num_pages - got,
+ write_page, pages + got);
if (rc < 0)
break;
BUG_ON(rc == 0);
got += rc;
}
- up_read(¤t->mm->mmap_sem);
if (rc < 0)
goto fail;
return pages;
--
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