Date: Thu, 15 Feb 2018 08:56:39 +0100 From: Michael Schuster <michaelsprivate@gmail.com> To: Per olof Ljungmark <peo@nethead.se> Cc: FreeBSD Mailing List <freebsd-questions@freebsd.org> Subject: Re: which limit is hit here? Message-ID: <CADqw_gKS=%2Be=PCgG6OJVfbuSwWD4zioZ__gnVNc5hYtM2Mfo%2Bg@mail.gmail.com> In-Reply-To: <d4d1093d-0db2-baed-0fb5-04b5127c8ccb@nethead.se> References: <d4d1093d-0db2-baed-0fb5-04b5127c8ccb@nethead.se>
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Hi Per, On Thu, Feb 15, 2018 at 8:41 AM, Per olof Ljungmark <peo@nethead.se> wrote: > Hi, > > A process "squatter" from Cyrus-IMAP version 2.5.11 exits with signal > 11. The purpose of the process is to create an index of the content in a > mailbox. > > On large mailboxes, squatter coredumps, the final message from truss reads: > > mmap(0x0,700448768,PROT_READ|PROT_WRITE,MAP_PRIVATE|MAP_ANON,-1,0x0) = > 34783363072 (0x819400000) > mmap(0x0,936334732,PROT_READ,MAP_SHARED,107,0x0) = 35483811840 > (0x843000000) > SIGNAL 11 (SIGSEGV) > process killed, signal = 11 (core dumped) > to me this looks like the error is happening *after* mmap() returned successfully - most likely because "someone" miscalculates some pointer and tries to access an unmapped address. Maybe (but that's conjecture), PROT_READ is wrong here and someone is attempting to write to that mapped region; I'm not 100% sure though whether that'd actually trigger SIGSEGV. I'd suggest you do something like $ gdb squatter core (gdb) bt and look at the output, and maybe go to the maintainers of Cyrus-IMAP... HTH Michael > and a tempfile is produced, always same size: > 3017208832 cyrus.squat.NEW > > Same result on 10.3 and 11-STABLE. > > Is there a knob to let squatter have the necessary resource to complete > the indexing? > > Thanks, > > //per > -- Michael Schuster http://recursiveramblings.wordpress.com/ recursion, n: see 'recursion'
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