* CRITICAL ls MEMORY LEAK @ 2021-02-21 15:18 neal.garrett 2021-02-21 18:05 ` Brian Inglis 2021-02-22 20:12 ` Doug Henderson 0 siblings, 2 replies; 6+ messages in thread From: neal.garrett @ 2021-02-21 15:18 UTC (permalink / raw) To: cygwin I deal with a lot of very large files on a regular basis. I've noticed that when I delve into these directories using in mintty and issue the command ls -l (or ls -color=auto), a very large junk of memory is consumed. The memory leak seems to be proportionate to the number and size of files within the containing folder. To reproduce: generate or use a folder containing 50 (or more) 2G+ files. // In this demonstration, I a ran the command on a directory containing 143 files ranging in size from 2GB to 5GB. $> free total used free shared buff/cache available Mem: 50276004 16465148 33810856 0 0 33810856 Swap: 12058624 186468 11872156 $> ls -l -color=auto . (contents displayed after some delay) $> free total used free shared buff/cache available Mem: 50276004 19844660 30431344 0 0 30431344 Swap: 12058624 186460 11872164 // After 10 consecutive executions of the 'ls -al --color=auto' command in this directory, ls has consumed 86% of my system's real memory. $> free total used free shared buff/cache available Mem: 50276004 43587560 6688444 0 0 6688444 Swap: 12058624 301068 11757556 // If I continue (usually unknowingly) my system will completely be depleted of resources to the point my mouse will barely respond to movement. -- ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: CRITICAL ls MEMORY LEAK 2021-02-21 15:18 CRITICAL ls MEMORY LEAK neal.garrett @ 2021-02-21 18:05 ` Brian Inglis 2021-02-22 20:12 ` Doug Henderson 1 sibling, 0 replies; 6+ messages in thread From: Brian Inglis @ 2021-02-21 18:05 UTC (permalink / raw) To: cygwin On 2021-02-21 08:18, Satalink via Cygwin wrote: > I deal with a lot of very large files on a regular basis. I've noticed that > when I delve into these directories using in mintty and issue the command ls > -l (or ls -color=auto), a very large junk of memory is consumed. The > memory leak seems to be proportionate to the number and size of files within > the containing folder. > > To reproduce: > > generate or use a folder containing 50 (or more) 2G+ files. > > // In this demonstration, I a ran the command on a directory containing 143 > files ranging in size from 2GB to 5GB. > $> free > total used free shared buff/cache available > Mem: 50276004 16465148 33810856 0 0 33810856 > Swap: 12058624 186468 11872156 > $> ls -l -color=auto > . (contents displayed after some delay) > $> free > total used free shared buff/cache available > Mem: 50276004 19844660 30431344 0 0 30431344 > Swap: 12058624 186460 11872164 > // After 10 consecutive executions of the 'ls -al --color=auto' command in > this directory, ls has consumed 86% of my system's real memory. > $> free > total used free shared buff/cache available > Mem: 50276004 43587560 6688444 0 0 6688444 > Swap: 12058624 301068 11757556 > // If I continue (usually unknowingly) my system will completely be depleted > of resources to the point my mouse will barely respond to movement. That number is just the amount of unused physical memory on the system, and will go down as you use the system, because unused memory is wasted meory. Better to use Windows utilities like Task Manager/Performance/Memory, Resource Monitor/Memory, or MS/SysInternals rammap which give system relevant details. You will probably find that a lot of your memory is in Standby which means it is being used to memory map or cache files, and it should be released when needed. Unfortunately Windows often can't release the memory as fast as programs want to use it. Just accessing files can cause AV/Defender to look at what you are doing, and have AV and Search take a look in the files, which uses and ties up a bunch of resources for a while. You need to look a bit further for longer to decide if there are real issues, and if so, where they are. -- Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada This email may be disturbing to some readers as it contains too much technical detail. Reader discretion is advised. [Data in binary units and prefixes, physical quantities in SI.] ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: CRITICAL ls MEMORY LEAK 2021-02-21 15:18 CRITICAL ls MEMORY LEAK neal.garrett 2021-02-21 18:05 ` Brian Inglis @ 2021-02-22 20:12 ` Doug Henderson 2021-02-22 20:30 ` Brian Inglis 1 sibling, 1 reply; 6+ messages in thread From: Doug Henderson @ 2021-02-22 20:12 UTC (permalink / raw) To: cygwin On Sun, 21 Feb 2021 at 08:21, Satalink via Cygwin <cygwin@cygwin.com> wrote: > > I deal with a lot of very large files on a regular basis. I've noticed that > when I delve into these directories using in mintty and issue the command ls > -l (or ls -color=auto), a very large junk of memory is consumed. The > memory leak seems to be proportionate to the number and size of files within > the containing folder. This is likely due to your virus scanner. If those files contain non-executable content, it is probably safe to disable virus scans for those files. Something that ls does is triggering the scan. That scan causes the virus scanner to read the entire file. You should see extraordinary GPU and disk activity for some time after the ls completes. There might be processes or at least threads for each file being scanned. Hopefully you will be able to identify a common folder in the path to those files where it is safe to disable scanning for that folder and all folders and files within that folder. HTH Doug -- Doug Henderson, Calgary, Alberta, Canada - from gmail.com ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: CRITICAL ls MEMORY LEAK 2021-02-22 20:12 ` Doug Henderson @ 2021-02-22 20:30 ` Brian Inglis 2021-02-22 21:50 ` Hans-Bernhard Bröker 0 siblings, 1 reply; 6+ messages in thread From: Brian Inglis @ 2021-02-22 20:30 UTC (permalink / raw) To: cygwin On 2021-02-22 13:12, Doug Henderson wrote: > On Sun, 21 Feb 2021 at 08:21, Satalink wrote: >> I deal with a lot of very large files on a regular basis. I've noticed that >> when I delve into these directories using in mintty and issue the command ls >> -l (or ls -color=auto), a very large junk of memory is consumed. The >> memory leak seems to be proportionate to the number and size of files within >> the containing folder. > This is likely due to your virus scanner. If those files contain > non-executable content, it is probably safe to disable virus scans for > those files. > > Something that ls does is triggering the scan. That scan causes the > virus scanner to read the entire file. You should see extraordinary > GPU and disk activity for some time after the ls completes. There > might be processes or at least threads for each file being scanned. > > Hopefully you will be able to identify a common folder in the path to > those files where it is safe to disable scanning for that folder and > all folders and files within that folder. I've often wondered if the heavy activity is due to Windows' defaults to writing files with F+RX perms which triggers executable virus scans? You can't have separate directory and file default perms and unlike Unix, Windows appears dumb about applying the X bit to files, probably because that would render downloaded executables non-X, and there is no easy way for users to change that, whereas Unix requires tools and users explicitly grant X perms. -- Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada This email may be disturbing to some readers as it contains too much technical detail. Reader discretion is advised. [Data in binary units and prefixes, physical quantities in SI.] ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: CRITICAL ls MEMORY LEAK 2021-02-22 20:30 ` Brian Inglis @ 2021-02-22 21:50 ` Hans-Bernhard Bröker 2021-02-22 23:47 ` Brian Inglis 0 siblings, 1 reply; 6+ messages in thread From: Hans-Bernhard Bröker @ 2021-02-22 21:50 UTC (permalink / raw) To: cygwin Am 22.02.2021 um 21:30 schrieb Brian Inglis: > I've often wondered if the heavy activity is due to Windows' defaults to > writing files with F+RX perms which triggers executable virus scans? That could only be the case if Windows actually had an 'x' permission bit. ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: CRITICAL ls MEMORY LEAK 2021-02-22 21:50 ` Hans-Bernhard Bröker @ 2021-02-22 23:47 ` Brian Inglis 0 siblings, 0 replies; 6+ messages in thread From: Brian Inglis @ 2021-02-22 23:47 UTC (permalink / raw) To: cygwin On 2021-02-22 14:50, Hans-Bernhard Bröker wrote: > Am 22.02.2021 um 21:30 schrieb Brian Inglis: > >> I've often wondered if the heavy activity is due to Windows' defaults to >> writing files with F+RX perms which triggers executable virus scans? > > That could only be the case if Windows actually had an 'x' permission bit. Strictly speaking, I am not sure if *Unix* has an 'x' permission bit, but most filesystems do provide such a facility (V/FAT e.g. some /boot/ do not), as do POSIX/Solaris ACLs, and Windows NTFS, whose ACLs have execute permissions: $ icacls /? | egrep exec\|X RX - read and execute access GE - generic execute X - execute/traverse GE grants FILE_EXECUTE and STANDARD_RIGHTS_EXECUTE access rights. Access Mask Format: |31|30|29|28|27|26|25|24|23|22|21|20|19|18|17|16|15|14|13|12|11|10|9|8|7|6|5|4|3|2|1|0| |GR|GW|GE|GA|27|26|25|AS|23|22|21|20|19|18|17|16|15|14|13|12|11|10|9|8|7|6|5|4|3|2|1|0| |..generic..|reserved|..|.......standard........|...........object.specific...........| GR GENERIC_READ GW GENERIC_WRITE GE GENERIC_EXECUTE GA GENERIC_ALL AS ACCESS_SYSTEM_SECURITY access Security ACL in object security descriptor Windows also supports ACLs on system objects, and there may be similar features on SELinux. -- Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada This email may be disturbing to some readers as it contains too much technical detail. Reader discretion is advised. [Data in binary units and prefixes, physical quantities in SI.] ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2021-02-22 23:47 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2021-02-21 15:18 CRITICAL ls MEMORY LEAK neal.garrett 2021-02-21 18:05 ` Brian Inglis 2021-02-22 20:12 ` Doug Henderson 2021-02-22 20:30 ` Brian Inglis 2021-02-22 21:50 ` Hans-Bernhard Bröker 2021-02-22 23:47 ` Brian Inglis
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