Re: [PATCH] improve performance of std::allocator::deallocate

2019-05-20 Thread Jonathan Wakely
On 20/05/19 19:21 +0200, François Dumont wrote: On 5/20/19 1:14 PM, Jonathan Wakely wrote: - r1->deallocate(p, 2); + r1->deallocate(p, 2, alignof(char)); + __builtin_printf("%d\n", (int)bytes_allocated); Was this last line really intended to be added ? No, and I've already removed it loca

Re: [PATCH] improve performance of std::allocator::deallocate

2019-05-20 Thread François Dumont
On 5/20/19 1:14 PM, Jonathan Wakely wrote: - r1->deallocate(p, 2); + r1->deallocate(p, 2, alignof(char)); + __builtin_printf("%d\n", (int)bytes_allocated); Was this last line really intended to be added ?

Re: [PATCH] improve performance of std::allocator::deallocate

2019-05-20 Thread Jonathan Wakely
On 20/05/19 10:44 +0100, Jonathan Wakely wrote: On 20/05/19 09:17 +, Pádraig Brady wrote: On 04/02/2019 07:33 PM, Padraig Brady wrote: On 03/07/2019 03:43 AM, Jonathan Wakely wrote: OK, that makes me feel better about it. It's presumably much easier to upgrade to 5.2 from 5.0 or 5.1 than

Re: [PATCH] improve performance of std::allocator::deallocate

2019-05-20 Thread Jonathan Wakely
On 20/05/19 09:17 +, Pádraig Brady wrote: On 04/02/2019 07:33 PM, Padraig Brady wrote: On 03/07/2019 03:43 AM, Jonathan Wakely wrote: OK, that makes me feel better about it. It's presumably much easier to upgrade to 5.2 from 5.0 or 5.1 than it would be from 4.x. How complicated is the f

Re: [PATCH] improve performance of std::allocator::deallocate

2019-05-20 Thread Pádraig Brady
On 04/02/2019 07:33 PM, Padraig Brady wrote: > On 03/07/2019 03:43 AM, Jonathan Wakely wrote: >> OK, that makes me feel better about it. It's presumably much easier to >> upgrade to 5.2 from 5.0 or 5.1 than it would be from 4.x. >> How complicated is the fix to prevent the crashes? Would it

Re: [PATCH] improve performance of std::allocator::deallocate

2019-04-02 Thread Pádraig Brady
On 03/07/2019 03:43 AM, Jonathan Wakely wrote: > On 06/03/19 22:27 +, Pádraig Brady wrote: >> >> >> On 03/06/2019 01:44 AM, Jonathan Wakely wrote: >>> On 06/03/19 09:20 +, Pádraig Brady wrote: On 03/06/2019 12:50 AM, Jonathan Wakely wrote: > On 06/03/19 02:43 +, Pádraig Brad

Re: [PATCH] improve performance of std::allocator::deallocate

2019-03-07 Thread Jonathan Wakely
On 06/03/19 22:27 +, Pádraig Brady wrote: On 03/06/2019 01:44 AM, Jonathan Wakely wrote: On 06/03/19 09:20 +, Pádraig Brady wrote: On 03/06/2019 12:50 AM, Jonathan Wakely wrote: On 06/03/19 02:43 +, Pádraig Brady wrote: On 02/26/2019 04:23 PM, Padraig Brady wrote: Note jema

Re: [PATCH] improve performance of std::allocator::deallocate

2019-03-06 Thread Pádraig Brady
On 03/06/2019 01:44 AM, Jonathan Wakely wrote: > On 06/03/19 09:20 +, Pádraig Brady wrote: >> On 03/06/2019 12:50 AM, Jonathan Wakely wrote: >>> On 06/03/19 02:43 +, Pádraig Brady wrote: On 02/26/2019 04:23 PM, Padraig Brady wrote: > >> Note jemalloc >= 5.1 is requ

Re: [PATCH] improve performance of std::allocator::deallocate

2019-03-06 Thread Jonathan Wakely
On 06/03/19 09:20 +, Pádraig Brady wrote: On 03/06/2019 12:50 AM, Jonathan Wakely wrote: On 06/03/19 02:43 +, Pádraig Brady wrote: On 02/26/2019 04:23 PM, Padraig Brady wrote: Note jemalloc >= 5.1 is required to fix a bug with 0 sizes. How serious is the bug? What are the symptoms

Re: [PATCH] improve performance of std::allocator::deallocate

2019-03-06 Thread Pádraig Brady
On 03/06/2019 12:50 AM, Jonathan Wakely wrote: > On 06/03/19 02:43 +, Pádraig Brady wrote: >> >> >> On 02/26/2019 04:23 PM, Padraig Brady wrote: >>> Note jemalloc >= 5.1 is required to fix a bug with 0 sizes. How serious is the bug? What are the symptoms? >>> I've updated th

Re: [PATCH] improve performance of std::allocator::deallocate

2019-03-06 Thread Jonathan Wakely
On 06/03/19 02:43 +, Pádraig Brady wrote: On 02/26/2019 04:23 PM, Padraig Brady wrote: Note jemalloc >= 5.1 is required to fix a bug with 0 sizes. How serious is the bug? What are the symptoms? I've updated the commit summary to say it's a crash. Arguably that's better than mem corrup

Re: [PATCH] improve performance of std::allocator::deallocate

2019-03-05 Thread Pádraig Brady
On 02/26/2019 04:23 PM, Padraig Brady wrote: > >> Note jemalloc >= 5.1 is required to fix a bug with 0 sizes. >> >> How serious is the bug? What are the symptoms? >> > I've updated the commit summary to say it's a crash. > Arguably that's better than mem corruption. > >> It looks like 5.1.0 is le

Re: [PATCH] improve performance of std::allocator::deallocate

2019-02-26 Thread Pádraig Brady
On 02/26/2019 05:50 AM, Jonathan Wakely wrote: > On 23/02/19 02:04 +, Pádraig Brady wrote: >> Attached is a simple patch which has been extensively tested within >> Facebook, >> and is enabled by default in our code base. >> >> Passing the size to the allocator allows it to optimize deallocat

Re: [PATCH] improve performance of std::allocator::deallocate

2019-02-26 Thread Jonathan Wakely
On 23/02/19 02:04 +, Pádraig Brady wrote: Attached is a simple patch which has been extensively tested within Facebook, and is enabled by default in our code base. Passing the size to the allocator allows it to optimize deallocation, and this was seen to significantly reduce the work require

[PATCH] improve performance of std::allocator::deallocate

2019-02-22 Thread Pádraig Brady
Attached is a simple patch which has been extensively tested within Facebook, and is enabled by default in our code base. Passing the size to the allocator allows it to optimize deallocation, and this was seen to significantly reduce the work required in jemalloc, with about 40% reduction in CPU c