Re: [PATCH] fs/select: add vmalloc fallback for select(2)

On 09/28/2016 06:30 PM, David Laight wrote: > From: Vlastimil Babka >> Sent: 27 September 2016 12:51 > ... >> Process name suggests it's part of db2 database. It seems it has to implement >> its own interface to select() syscall, because glibc itself seems to have a >> FD_SETSIZE limit of 1024,

Re: [PATCH] fs/select: add vmalloc fallback for select(2)

On 09/28/2016 06:30 PM, David Laight wrote: > From: Vlastimil Babka >> Sent: 27 September 2016 12:51 > ... >> Process name suggests it's part of db2 database. It seems it has to implement >> its own interface to select() syscall, because glibc itself seems to have a >> FD_SETSIZE limit of 1024,

RE: [PATCH] fs/select: add vmalloc fallback for select(2)

From: Vlastimil Babka > Sent: 27 September 2016 12:51 ... > Process name suggests it's part of db2 database. It seems it has to implement > its own interface to select() syscall, because glibc itself seems to have a > FD_SETSIZE limit of 1024, which is probably why this wasn't an issue for all >

RE: [PATCH] fs/select: add vmalloc fallback for select(2)

From: Vlastimil Babka > Sent: 27 September 2016 12:51 ... > Process name suggests it's part of db2 database. It seems it has to implement > its own interface to select() syscall, because glibc itself seems to have a > FD_SETSIZE limit of 1024, which is probably why this wasn't an issue for all >

Re: [PATCH] fs/select: add vmalloc fallback for select(2)

On 09/27/2016 01:42 PM, Nicholas Piggin wrote: On Tue, 27 Sep 2016 11:37:24 + David Laight wrote: From: Nicholas Piggin > Sent: 27 September 2016 12:25 > On Tue, 27 Sep 2016 10:44:04 +0200 > Vlastimil Babka wrote: > > > What's your customer doing

Re: [PATCH] fs/select: add vmalloc fallback for select(2)

On 09/27/2016 01:42 PM, Nicholas Piggin wrote: On Tue, 27 Sep 2016 11:37:24 + David Laight wrote: From: Nicholas Piggin > Sent: 27 September 2016 12:25 > On Tue, 27 Sep 2016 10:44:04 +0200 > Vlastimil Babka wrote: > > > What's your customer doing with those selects? If they care at all

Re: [PATCH] fs/select: add vmalloc fallback for select(2)

On Tue, 27 Sep 2016 11:37:24 + David Laight wrote: > From: Nicholas Piggin > > Sent: 27 September 2016 12:25 > > On Tue, 27 Sep 2016 10:44:04 +0200 > > Vlastimil Babka wrote: > > > > > On 09/23/2016 06:47 PM, Jason Baron wrote: > > > > Hi, > > >

Re: [PATCH] fs/select: add vmalloc fallback for select(2)

On Tue, 27 Sep 2016 11:37:24 + David Laight wrote: > From: Nicholas Piggin > > Sent: 27 September 2016 12:25 > > On Tue, 27 Sep 2016 10:44:04 +0200 > > Vlastimil Babka wrote: > > > > > On 09/23/2016 06:47 PM, Jason Baron wrote: > > > > Hi, > > > > > > > > On 09/23/2016 03:24 AM,

RE: [PATCH] fs/select: add vmalloc fallback for select(2)

From: Nicholas Piggin > Sent: 27 September 2016 12:25 > On Tue, 27 Sep 2016 10:44:04 +0200 > Vlastimil Babka wrote: > > > On 09/23/2016 06:47 PM, Jason Baron wrote: > > > Hi, > > > > > > On 09/23/2016 03:24 AM, Nicholas Piggin wrote: > > >> On Fri, 23 Sep 2016 14:42:53 +0800 > >

RE: [PATCH] fs/select: add vmalloc fallback for select(2)

From: Nicholas Piggin > Sent: 27 September 2016 12:25 > On Tue, 27 Sep 2016 10:44:04 +0200 > Vlastimil Babka wrote: > > > On 09/23/2016 06:47 PM, Jason Baron wrote: > > > Hi, > > > > > > On 09/23/2016 03:24 AM, Nicholas Piggin wrote: > > >> On Fri, 23 Sep 2016 14:42:53 +0800 > > >> "Hillf

Re: [PATCH] fs/select: add vmalloc fallback for select(2)

On Tue, 27 Sep 2016 10:44:04 +0200 Vlastimil Babka wrote: > On 09/23/2016 06:47 PM, Jason Baron wrote: > > Hi, > > > > On 09/23/2016 03:24 AM, Nicholas Piggin wrote: > >> On Fri, 23 Sep 2016 14:42:53 +0800 > >> "Hillf Danton" wrote: > >> > >

Re: [PATCH] fs/select: add vmalloc fallback for select(2)

On Tue, 27 Sep 2016 10:44:04 +0200 Vlastimil Babka wrote: > On 09/23/2016 06:47 PM, Jason Baron wrote: > > Hi, > > > > On 09/23/2016 03:24 AM, Nicholas Piggin wrote: > >> On Fri, 23 Sep 2016 14:42:53 +0800 > >> "Hillf Danton" wrote: > >> > > The select(2) syscall performs a

Re: [PATCH] fs/select: add vmalloc fallback for select(2)

On 09/23/2016 06:47 PM, Jason Baron wrote: Hi, On 09/23/2016 03:24 AM, Nicholas Piggin wrote: On Fri, 23 Sep 2016 14:42:53 +0800 "Hillf Danton" wrote: The select(2) syscall performs a kmalloc(size, GFP_KERNEL) where size grows with the number of fds passed. We had

Re: [PATCH] fs/select: add vmalloc fallback for select(2)

On 09/23/2016 06:47 PM, Jason Baron wrote: Hi, On 09/23/2016 03:24 AM, Nicholas Piggin wrote: On Fri, 23 Sep 2016 14:42:53 +0800 "Hillf Danton" wrote: The select(2) syscall performs a kmalloc(size, GFP_KERNEL) where size grows with the number of fds passed. We had a customer report page

Re: [PATCH] fs/select: add vmalloc fallback for select(2)

Hi, On 09/23/2016 03:24 AM, Nicholas Piggin wrote: On Fri, 23 Sep 2016 14:42:53 +0800 "Hillf Danton" wrote: The select(2) syscall performs a kmalloc(size, GFP_KERNEL) where size grows with the number of fds passed. We had a customer report page allocation failures

Re: [PATCH] fs/select: add vmalloc fallback for select(2)

Hi, On 09/23/2016 03:24 AM, Nicholas Piggin wrote: On Fri, 23 Sep 2016 14:42:53 +0800 "Hillf Danton" wrote: The select(2) syscall performs a kmalloc(size, GFP_KERNEL) where size grows with the number of fds passed. We had a customer report page allocation failures of order-4 for this

Re: [PATCH] fs/select: add vmalloc fallback for select(2)

On Fri, 23 Sep 2016 14:42:53 +0800 "Hillf Danton" wrote: > > > > The select(2) syscall performs a kmalloc(size, GFP_KERNEL) where size grows > > with the number of fds passed. We had a customer report page allocation > > failures of order-4 for this allocation. This is

Re: [PATCH] fs/select: add vmalloc fallback for select(2)

On Fri, 23 Sep 2016 14:42:53 +0800 "Hillf Danton" wrote: > > > > The select(2) syscall performs a kmalloc(size, GFP_KERNEL) where size grows > > with the number of fds passed. We had a customer report page allocation > > failures of order-4 for this allocation. This is a costly order, so it

Re: [PATCH] fs/select: add vmalloc fallback for select(2)

> > The select(2) syscall performs a kmalloc(size, GFP_KERNEL) where size grows > with the number of fds passed. We had a customer report page allocation > failures of order-4 for this allocation. This is a costly order, so it might > easily fail, as the VM expects such allocation to have a

Re: [PATCH] fs/select: add vmalloc fallback for select(2)

> > The select(2) syscall performs a kmalloc(size, GFP_KERNEL) where size grows > with the number of fds passed. We had a customer report page allocation > failures of order-4 for this allocation. This is a costly order, so it might > easily fail, as the VM expects such allocation to have a

Re: [PATCH] fs/select: add vmalloc fallback for select(2)

On 09/22/2016 06:24 PM, Eric Dumazet wrote: + bits = kmalloc(alloc_size, GFP_KERNEL|__GFP_NOWARN); + if (!bits && alloc_size > PAGE_SIZE) { + bits = vmalloc(alloc_size); + + if (!bits) + goto

Re: [PATCH] fs/select: add vmalloc fallback for select(2)

On 09/22/2016 06:24 PM, Eric Dumazet wrote: + bits = kmalloc(alloc_size, GFP_KERNEL|__GFP_NOWARN); + if (!bits && alloc_size > PAGE_SIZE) { + bits = vmalloc(alloc_size); + + if (!bits) + goto

Re: [PATCH] fs/select: add vmalloc fallback for select(2)

On Thu, 2016-09-22 at 17:28 +0200, Vlastimil Babka wrote: > The select(2) syscall performs a kmalloc(size, GFP_KERNEL) where size grows > with the number of fds passed. We had a customer report page allocation > failures of order-4 for this allocation. This is a costly order, so it might > easily

Re: [PATCH] fs/select: add vmalloc fallback for select(2)

On Thu, 2016-09-22 at 17:28 +0200, Vlastimil Babka wrote: > The select(2) syscall performs a kmalloc(size, GFP_KERNEL) where size grows > with the number of fds passed. We had a customer report page allocation > failures of order-4 for this allocation. This is a costly order, so it might > easily