Re: 1st character change in file takes forever

[David Klein <dklein@bloombergREMOVETHISPART.com>]

Barry Margolin <barmar@genuity.net> writes:

> In article <m08yyodagg.fsf@bloombergREMOVETHISPART.com>,
> David Klein  <dklein@bloombergREMOVETHISPART.com> wrote:
> >When I first try to insert a character into a buffer that is
> >associated with a file on disk, the insert takes close to a minute!
> 
> During that first change, Emacs checks whether someone else has modified
> the file, and also checks for a lock file.  For some reason, these checks
> are taking a long time.  Try doing a system call trace to see what it's
> doing during that time.
> 

Assuming by "a system call trace" you meant the strace function, I did
the following:

> emacs junk1&
> strace -c -f -ff -o emacs_trace -q -r -t -T -p1238
(1238 was the pid of emacs. After running the strace command, I
 pressed the spacebar once in emacs. When it finally inserted the
 space into the buffer, I ^C'ed the strace).
> cat emacs_trace
% time     seconds  usecs/call     calls    errors syscall
------ ----------- ----------- --------- --------- ----------------
 98.46   12.598431          49    255963           read
  1.21    0.154380        5718        27           select
  0.13    0.016690          98       170           ioctl
  0.06    0.007652          93        82           sigreturn
  0.06    0.007152         170        42           SYS_174
  0.03    0.004175          66        63           alarm
  0.03    0.004048          92        44           fcntl
  0.02    0.002571         234        11           write
  0.00    0.000091           4        26           kill
  0.00    0.000070          70         1           symlink
  0.00    0.000068           3        27           getpid
  0.00    0.000038           3        13           gettimeofday
  0.00    0.000033          11         3         3 access
  0.00    0.000024          12         2         1 open
  0.00    0.000020          20         1           stat
  0.00    0.000011           4         3           SYS_175
  0.00    0.000008           8         1           close
  0.00    0.000004           4         1           lseek
------ ----------- ----------- --------- --------- ----------------
100.00   12.795466                256480         4 total


I have no idea how to continue, besides the fact that 255963 read
syscalls seems slightly on the high side for inserting a single
character. Any ideas how to continue?

-- 
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