Re: [PATCH] fs/select: add vmalloc fallback for select(2)
From: Vlastimil Babka <hidden>
Date: 2016-09-27 11:51:03
Also in:
linux-fsdevel, linux-mm, lkml
On 09/27/2016 01:42 PM, Nicholas Piggin wrote:
On Tue, 27 Sep 2016 11:37:24 +0000 David Laight [off-list ref] wrote:quoted
From: Nicholas Pigginquoted
Sent: 27 September 2016 12:25 On Tue, 27 Sep 2016 10:44:04 +0200 Vlastimil Babka [off-list ref] wrote: What's your customer doing with those selects? If they care at all about performance, I doubt they want select to attempt order-4 allocations, fail, then use vmalloc :)If they care about performance they shouldn't be passing select() lists that are anywhere near that large. If the number of actual fd is small - use poll().Right. Presumably it's some old app they're still using, no?
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 the years... -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>