Re: [PATCH v3 3/3] vfs: Use per-cpu list for superblock's inode list

2016-02-25 Thread Waiman Long
On 02/24/2016 03:23 PM, Waiman Long wrote: On 02/24/2016 03:28 AM, Jan Kara wrote: On Tue 23-02-16 14:04:32, Waiman Long wrote: When many threads are trying to add or delete inode to or from a superblock's s_inodes list, spinlock contention on the list can become a performance bottleneck. This

Re: [PATCH v3 3/3] vfs: Use per-cpu list for superblock's inode list

2016-02-25 Thread Waiman Long
On 02/25/2016 03:06 AM, Ingo Molnar wrote: * Jan Kara wrote: With an exit microbenchmark that creates a large number of threads, attachs many inodes to them and then exits. The runtimes of that microbenchmark with 1000 threads before and after the patch on a 4-socket Intel E7-4820 v3 system (4

Re: [PATCH v3 3/3] vfs: Use per-cpu list for superblock's inode list

2016-02-25 Thread Ingo Molnar
* Jan Kara wrote: > > > > With an exit microbenchmark that creates a large number of threads, > > > > attachs many inodes to them and then exits. The runtimes of that > > > > microbenchmark with 1000 threads before and after the patch on a > > > > 4-socket > > > > Intel E7-4820 v3 system (40

Re: [PATCH v3 3/3] vfs: Use per-cpu list for superblock's inode list

2016-02-24 Thread Waiman Long
On 02/24/2016 03:28 AM, Jan Kara wrote: On Tue 23-02-16 14:04:32, Waiman Long wrote: When many threads are trying to add or delete inode to or from a superblock's s_inodes list, spinlock contention on the list can become a performance bottleneck. This patch changes the s_inodes field to become

Re: [PATCH v3 3/3] vfs: Use per-cpu list for superblock's inode list

2016-02-24 Thread Jan Kara
On Wed 24-02-16 09:36:30, Ingo Molnar wrote: > > * Jan Kara wrote: > > > On Tue 23-02-16 14:04:32, Waiman Long wrote: > > > When many threads are trying to add or delete inode to or from > > > a superblock's s_inodes list, spinlock contention on the list can > > > become a performance bottleneck

Re: [PATCH v3 3/3] vfs: Use per-cpu list for superblock's inode list

2016-02-24 Thread Ingo Molnar
* Jan Kara wrote: > On Tue 23-02-16 14:04:32, Waiman Long wrote: > > When many threads are trying to add or delete inode to or from > > a superblock's s_inodes list, spinlock contention on the list can > > become a performance bottleneck. > > > > This patch changes the s_inodes field to become

Re: [PATCH v3 3/3] vfs: Use per-cpu list for superblock's inode list

2016-02-24 Thread Jan Kara
On Tue 23-02-16 14:04:32, Waiman Long wrote: > When many threads are trying to add or delete inode to or from > a superblock's s_inodes list, spinlock contention on the list can > become a performance bottleneck. > > This patch changes the s_inodes field to become a per-cpu list with > per-cpu spi

[PATCH v3 3/3] vfs: Use per-cpu list for superblock's inode list

2016-02-23 Thread Waiman Long
When many threads are trying to add or delete inode to or from a superblock's s_inodes list, spinlock contention on the list can become a performance bottleneck. This patch changes the s_inodes field to become a per-cpu list with per-cpu spinlocks. As a result, the following superblock inode list