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Bug #80061 Copying large files may have suboptimal performance
Submitted: 2020-09-04 16:29 UTC Modified: 2020-09-21 14:11 UTC
From: cmb@php.net Assigned: cmb (profile)
Status: Closed Package: Performance problem
PHP Version: 7.4Git-2020-09-04 (Git) OS: *
Private report: No CVE-ID: None
 [2020-09-04 16:29 UTC] cmb@php.net
Description:
------------
As of PHP 7.4.0, large files are supposed to be copied by mapping
them into virtual memory at once.  That obviously can't work for
files which are larger than any possibly free memory segment.  So
copying files of 1 GiB or 2 GiB is not unlikely to fail for x86
architectures, for instance.  If the memory mapping fails, we fall
back to reading and writing in small chunks, which has suboptimal
performance.

See also <https://github.com/php/php-src/pull/5319#issuecomment-605901029>.



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 [2020-09-04 16:29 UTC] cmb@php.net
-Assigned To: +Assigned To: cmb
 [2020-09-04 16:56 UTC] cmb@php.net
The following pull request has been associated:

Patch Name: Fix mmap copying
On GitHub:  https://github.com/php/php-src/pull/6078
Patch:      https://github.com/php/php-src/pull/6078.patch
 [2020-09-21 14:11 UTC] cmb@php.net
-Status: Assigned +Status: Closed
 
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