On Wed, 30 Apr 2014 20:41:38 +0900 (JST) HATAYAMA Daisuke <d.hatayama at jp.fujitsu.com> wrote: > From: Wang Nan <wangnan0 at huawei.com> > Subject: [PATCH 0/4] Replace lseek..write/read to pwrite/pread > Date: Sat, 26 Apr 2014 12:07:05 +0800 > > > In original code there are many operations read from /write to specific > > positions of a file. This series of patches replace such patterns to > > pread/pwrite calls, reduces more than 100 lines of code. > > > > I'm now writing pthread support patch set and it will naturally > include pread/pwrite like this patch set. > > It sounds to me that using pread/pwrite only to reduce lseek code is > weak in motivation. Is there another visible merit? For example, any > kind of performance improvement. I guess it's small even if exists > compared to I/O. There is no user-visible benefit just from applying the patch, that's right. The main benefit is that these pread/pwrite operations are atomic and do not move the file offset, so all subprocesses (or threads) can share the same file descriptor. This allows to remove reopen_dump_memory(), for example. Anyway, is improving code readability really so weak argument? Petr T
