From: Daniel Jordan <daniel.m.jordan@oracle.com>
To: akpm@linux-foundation.org
Cc: daniel.m.jordan@oracle.com, Alan Tull <atull@kernel.org>,
Christoph Lameter <cl@linux.com>,
Davidlohr Bueso <dave@stgolabs.net>,
Moritz Fischer <mdf@kernel.org>, Wu Hao <hao.wu@intel.com>,
linux-mm@kvack.org, linux-fpga@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [PATCH 4/6] fpga/dlf/afu: drop mmap_sem now that locked_vm is atomic
Date: Tue, 2 Apr 2019 16:41:56 -0400 [thread overview]
Message-ID: <20190402204158.27582-5-daniel.m.jordan@oracle.com> (raw)
In-Reply-To: <20190402204158.27582-1-daniel.m.jordan@oracle.com>
With locked_vm now an atomic, there is no need to take mmap_sem as
writer. Delete and refactor accordingly.
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Alan Tull <atull@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Moritz Fischer <mdf@kernel.org>
Cc: Wu Hao <hao.wu@intel.com>
Cc: <linux-mm@kvack.org>
Cc: <linux-fpga@vger.kernel.org>
Cc: <linux-kernel@vger.kernel.org>
---
drivers/fpga/dfl-afu-dma-region.c | 40 ++++++++++++-------------------
1 file changed, 15 insertions(+), 25 deletions(-)
diff --git a/drivers/fpga/dfl-afu-dma-region.c b/drivers/fpga/dfl-afu-dma-region.c
index 08132fd9b6b7..81e3e3a71758 100644
--- a/drivers/fpga/dfl-afu-dma-region.c
+++ b/drivers/fpga/dfl-afu-dma-region.c
@@ -35,46 +35,36 @@ void afu_dma_region_init(struct dfl_feature_platform_data *pdata)
* afu_dma_adjust_locked_vm - adjust locked memory
* @dev: port device
* @npages: number of pages
- * @incr: increase or decrease locked memory
*
* Increase or decrease the locked memory size with npages input.
*
* Return 0 on success.
* Return -ENOMEM if locked memory size is over the limit and no CAP_IPC_LOCK.
*/
-static int afu_dma_adjust_locked_vm(struct device *dev, long npages, bool incr)
+static int afu_dma_adjust_locked_vm(struct device *dev, long pages)
{
- unsigned long locked, lock_limit;
+ unsigned long lock_limit;
s64 locked_vm;
int ret = 0;
/* the task is exiting. */
- if (!current->mm)
+ if (!current->mm || !pages)
return 0;
- down_write(¤t->mm->mmap_sem);
-
- locked_vm = atomic64_read(¤t->mm->locked_vm);
- if (incr) {
- locked = locked_vm + npages;
+ locked_vm = atomic64_add_return(pages, ¤t->mm->locked_vm);
+ WARN_ON_ONCE(locked_vm < 0);
+ if (pages > 0 && !capable(CAP_IPC_LOCK)) {
lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
-
- if (locked > lock_limit && !capable(CAP_IPC_LOCK))
+ if (locked_vm > lock_limit) {
ret = -ENOMEM;
- else
- atomic64_add(npages, ¤t->mm->locked_vm);
- } else {
- if (WARN_ON_ONCE(npages > locked_vm))
- npages = locked_vm;
- atomic64_sub(npages, ¤t->mm->locked_vm);
+ atomic64_sub(pages, ¤t->mm->locked_vm);
+ }
}
dev_dbg(dev, "[%d] RLIMIT_MEMLOCK %c%ld %lld/%lu%s\n", current->pid,
- incr ? '+' : '-', npages << PAGE_SHIFT,
- (s64)atomic64_read(¤t->mm->locked_vm) << PAGE_SHIFT,
- rlimit(RLIMIT_MEMLOCK), ret ? "- exceeded" : "");
-
- up_write(¤t->mm->mmap_sem);
+ (pages > 0) ? '+' : '-', pages << PAGE_SHIFT,
+ locked_vm << PAGE_SHIFT, rlimit(RLIMIT_MEMLOCK),
+ ret ? "- exceeded" : "");
return ret;
}
@@ -94,7 +84,7 @@ static int afu_dma_pin_pages(struct dfl_feature_platform_data *pdata,
struct device *dev = &pdata->dev->dev;
int ret, pinned;
- ret = afu_dma_adjust_locked_vm(dev, npages, true);
+ ret = afu_dma_adjust_locked_vm(dev, npages);
if (ret)
return ret;
@@ -123,7 +113,7 @@ static int afu_dma_pin_pages(struct dfl_feature_platform_data *pdata,
free_pages:
kfree(region->pages);
unlock_vm:
- afu_dma_adjust_locked_vm(dev, npages, false);
+ afu_dma_adjust_locked_vm(dev, -npages);
return ret;
}
@@ -143,7 +133,7 @@ static void afu_dma_unpin_pages(struct dfl_feature_platform_data *pdata,
put_all_pages(region->pages, npages);
kfree(region->pages);
- afu_dma_adjust_locked_vm(dev, npages, false);
+ afu_dma_adjust_locked_vm(dev, -npages);
dev_dbg(dev, "%ld pages unpinned\n", npages);
}
--
2.21.0
next prev parent reply other threads:[~2019-04-02 23:16 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-02 20:41 [PATCH 0/6] convert locked_vm from unsigned long to atomic64_t Daniel Jordan
2019-04-02 20:41 ` [PATCH 1/6] mm: change locked_vm's type " Daniel Jordan
2019-04-02 22:04 ` Andrew Morton
2019-04-02 23:43 ` Davidlohr Bueso
2019-04-03 16:07 ` Daniel Jordan
2019-04-03 15:58 ` Daniel Jordan
2019-04-03 4:46 ` Christophe Leroy
2019-04-03 16:09 ` Daniel Jordan
2019-04-11 4:22 ` Alexey Kardashevskiy
2019-04-11 9:55 ` Mark Rutland
2019-04-11 20:28 ` Daniel Jordan
2019-04-16 23:33 ` Andrew Morton
2019-04-22 15:54 ` Daniel Jordan
2019-04-02 20:41 ` [PATCH 2/6] vfio/type1: drop mmap_sem now that locked_vm is atomic Daniel Jordan
2019-04-02 20:41 ` [PATCH 3/6] vfio/spapr_tce: " Daniel Jordan
2019-04-02 20:41 ` Daniel Jordan [this message]
2019-04-02 20:41 ` [PATCH 5/6] powerpc/mmu: " Daniel Jordan
2019-04-03 4:58 ` Christophe Leroy
2019-04-03 16:40 ` Daniel Jordan
2019-04-24 2:15 ` Davidlohr Bueso
2019-04-24 2:31 ` Davidlohr Bueso
2019-04-24 11:10 ` Jason Gunthorpe
2019-04-25 1:47 ` Daniel Jordan
2019-04-02 20:41 ` [PATCH 6/6] kvm/book3s: " Daniel Jordan
2019-04-03 12:51 ` [PATCH 0/6] convert locked_vm from unsigned long to atomic64_t Steven Sistare
2019-04-03 16:52 ` Daniel Jordan
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